How to Tell if the Breather Read Is Bad Lawn Mower

I like to perform my ain maintenance on my Briggs & Stratton engine and enjoy helping others do the same.

Earlier you shell out for an expensive repair to your Briggs & Stratton, read through this helpful guide to learning how to diagnose and set up your backyard mower's potential compression release problems.

Alexas_Fotos, CC0-BY, via Pixabay

Is Your Briggs and Stratton Hard to First?

Does the engine struggle to turn over, and information technology seems as though the starter must exist bad or the battery dead? Is it fourth dimension to pay big bucks for lawnmower repair? How will y'all get that lawn tractor to the repair shop?

Earlier y'all do anything likewise desperate, keep in heed that it may not be that serious of a problem. If this is an overhead valve (OHV) engine, and so information technology may be that you lot have just overlooked a bones maintenance procedure. Sometimes you have an easy repair on your lawn tractor.

Most of the overhead valve engines have a pinch release feature that allows for the starter to non have to work difficult to crank the engine. It's a slight raising, or crash-land, on the lobe of the camshaft. What it does is open up the valve a piddling early to let excess compression to drain off. At speeds over 300 rpm, the tappet just sort of floats over this bump, and it has no effect on engine functioning. Merely at starting speeds, it'due south essential, otherwise the starter just can't turn the engine over.

If the engine will plough over easily and hiccups, won't rev or make power, or only won't first, and so you may be looking at a fuel supply problem.

This guide volition help you lot diagnose and fix your difficult-to-showtime Briggs & Stratton engine.

How to Diagnose Your Backyard Mower Engine'due south Problem

To diagnose this problem, you volition demand a voltmeter.

Outset, check the battery voltage by using the voltmeter on each battery terminal. You should accept about 12 volts.

Next, check the voltage at the starter with the cardinal in the start position. You may demand a helper at this signal, depending on the equipment. What you have to do is ensure that all safety features are activated just as though you are starting the engine. With one lead from the voltmeter on the post, on the starter where the cable connects and the other leads to a good basis such as the engine block, there should be about the same voltage as there was at the battery. A drop of a volt isn't a concern. If all this checks out okay, then it'southward a reasonable diagnosis to suspect the compression release.

Proper performance of the pinch release requires proper valve lash adjustment. Adjusting the valves is a relatively unproblematic project requiring only a few tools and in one case yous learn how to practise it, yous should include it with your annual maintenance plan.

• Ratchet with extension and 3/8", vii/16" and 1/two" sockets
• Feeler gauge in .004" and .006"
• 3/8" wooden dowel or substitute
• Torx or Allen driver to fit lock spiral

How to Fix a Pinch Release Problem in Your Briggs & Stratton Engine

1. First, you need to access the valve cover. This volition be the silver cover on top of the engine head. It will take OHV stamped into information technology and is held on with 4 screws/bolts. These screws are ordinarily three/8" or seven/16" hex caput and are removed using a socket and ratchet. In that location is a gasket betwixt the valve comprehend and head. If y'all are careful, you can usually re-use this. Then remove the spark plug.
2. At present with the cover off, you can see the rockers, push button rods, valve springs, and valve stems. The valves are the ones with the springs on them. If you plough the flywheel by hand, yous will see the valves move up and down and see how the assembly works.
3. Find the intake valve. This will exist the one that the carburetor feeds fuel and air into. If you remove the pushrods, typically the intake valve will have an aluminum pushrod, while the exhaust valve has a steel pushrod.
4. You will need to plow the flywheel clockwise until you see this valve open (move downwards) and then close once again. In one case the intake valve closes, the piston will exist headed to the tiptop of its travel, or Acme Dead Middle (TDC).
5. At this indicate, take the wooden dowel and insert information technology into the spark plug hole. You should feel the pinnacle of the piston.
6. Slowly turn the flywheel by manus while holding the dowel against the piston, and you will feel the piston movement. Exist careful doing this. If the dowel starts to become defenseless in a bind, back the piston upwardly and remove the dowel. You only want the dowel in the cylinder when the piston is at or nearly the top of its travel.
7. With the piston at TDC, rock the flywheel back and along to find the highest spot of the piston travel using your dowel.
8. Find a spot on the head that's easy to run into, and mark the dowel where it lines up with that spot. Now remove the dowel and brand another mark 1/4" higher up the first mark.
9. The valve lash should be set with the piston at 1/iv" past TDC. What you are doing is making a gauge to line up the piston travel with a reference signal. At present put the dowel back in, and rotate the flywheel so that the piston is now 1/4" past TDC.
10. On the rockers, the stamped metallic pieces that open up the valves, there will be a nut and a lock screw within that nut. Usually this spiral volition be a Torx head, only whatsoever it is, loosen it and then loosen the retaining nut. You will notice the slack in the rockers, the amount of slack is what you are adjusting.
11. For the intake valve, have the .004" feeler gauge and insert it between the valve stem and rocker. Then tighten the retaining nut until the feeler gauge will just barely slide in and out. It should exist a snug fit, and the guess should have some resistance when trying to pull it out.
12. So tighten the lock screw back downwardly. That valve is finished.
13. Repeat the feeler gauge procedure on the frazzle valve using the .006" gauge, and replace the valve cover.
14. If the gasket tore when you removed information technology or information technology isn't in the best of condition, y'all tin can either buy a new gasket or do what we do in the store and utilise PermaTex Ultra Black to re-seal the valve comprehend. Nosotros also use anti-seize on the valve cover screws. Both PermaTex and anti-seize are available at any auto parts store, as well as the tools required. (Note: If yous have a twin cylinder engine, you have to care for each cylinder separately. You have to bring each piston to its respective TDC to arrange each cylinder's valves.)
15. Once you have the valve cover dorsum on, you're ready to start the engine. Don't worry if it'south even so doing the same as before. It usually have a few tries to exercise this right if you've never adjusted valve lash. But first over and try it a couple more times if necessary. If y'all can't get it right after several tries, y'all may take a unlike problem which volition require further diagnosis.

Thanks for reading this, and I hope it is of some assistance. Several people take sent me messages request for further help in diagnosis. But please understand, due to constraints within this type of forum, at that place is just no way for me to practise that here.

Briggs & Stratton Pinch Release Fix

Read More From Dengarden

This article is accurate and truthful to the best of the author's cognition. Content is for informational or amusement purposes only and does non substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Dave Lovekin on June 10, 2018:

Fixed a pinch blocked starter in 10 minutes. Great article, thanks for submitting.

Shayne Campbell on May 09, 2016:

It is a common trouble also for the exhaust valve port to get striking, due to the cooling passages getting plugged with grass. This can cause the frazzle valve guide to slide out of the.passage and lock the valve up, causing the pushrod to curve. Fortunately if one is mechanically inclined, this is appx an $lxxx repair with oil, parts, and gaskets. To eliminate this problem in the future, I drill a hole in the side of the head where the frazzle valve guide is, and installed a loctited ready spiral into the valve guide, eliminating the possibility of any movement. I recommend the valve clearance adjustment annually, or as the no crank (high compression) upshot resurfaces.

Doug Cutler from Temperance. Mich on August fourteen, 2015:

Afterward working on these type engines I decided to practise a hub. Did a search to see what hubs were already here. Found this one. May exercise another explaining why the 1/4" piston down and the carb. flooding problem.

You would recollect the shops would know most these bug. I got i in to repair that had the boosted trouble of gas getting into the cylinder from the carb. needle not seating. That extra gas in the cyl. volition do the same every bit the decompression non working. I got the actress gas out and after jumping the battery it finally started. It was then starting easily merely smoked badly. Turns out the the caput gasket blew between the cyl. and button rod crenel. Another common problem with these OHV engines. Changed the gasket adjusted the valves. Engine returned to previous trouble of non turning over. When it was starting easily and smoking badly the burned spot in the gasket was a built in pinch release. So this means the pinch release pin on the intake lob of the camshaft is non operation. This is why when adjusting the valves on these engines, with a properly working decompression system, the piston needs to be ane/four" down to articulate the pin. Adjacent is to have the engine off and apart to ready the camshaft decompression system.

James Rosen from Connecticut on August 02, 2015:

Cheers for this clear write-up. I just acquired a Husqvarna tractor with a 20 HP Briggs Intek single cylinder motor that would not commencement easily. I found the exhaust at 0.010 and intake at 0.005. All looked like new when I pulled the valve cover no sludge or varnish. I reset both to factory spec using procedure you described and the motor now starts easily and runs polish. But issue left is it will run for almost x minutes misfire two-3 times repeat this nigh 4-5 times then stop running. A wait of 2-3 minutes and information technology volition kickoff and run fine for another 5-x minutes and the cycle repeats. I institute the greyness wire to the fuel cutoff solenoid partially melted to the motor heat shield but notwithstanding not the outcome even after repair. The engine has 438 hour run time on the tractor hour meter. Could this be the electronic ignition starting to fail? I have an inductive timing light to check for spark during whatsoever misfire simply is at that place any better test that does non require waiting for the misfire to happen short of replace and see. Also the plug was blackness and wet when pulled to prepare the valve lash. Is 438 hours on this engine considered a lot or should i expect many more with correct maintenance

James Rosen from Connecticut on Baronial 01, 2015:

Cheers I have a 20 hp Intek single cylinder Hsuqvarna tractor just caused as a clear information technology out of my garage find. I plant the frazzle at .010 when I checked and intake at .005 438 hours on the meter gauge valves where never adjusted. Used described procedure and starts similar a gnaw. this was a great helpful post. concluding event I have is after about 10 to 15 minutes the motor starts to miss fire 2 or 3 times in a row does this 4 or 5 times and then shortly dies. If I expect a minute or ii information technology will start right upwardly and run with no problem for another short period of time. though I institute the consequence with the grey lead to the fuel cut off solenoid partially melted to the motor heat shield but no luck. Could this be the ignition module. The ability to restart after a short cool down wait period seems to signal there. I have an inductive timing light ( yes I run old Land Rovers which crave old schoolhouse tools) but have not checked for no spark yet.

Is there whatever known issue with fuel pump or vapor lock on these motors.

is 430+ hours considered end of life by Briggs for this motor.

bktrider on July fourteen, 2015:

Hi, had to register just to post this comment: I take watched videos of this process and acquire best from watching, however, his article was one of the best that I have read almost any topic. Y'all have excellent writing skills and I really appreciate y'all posting this article. A friend of mine has a Snapper with a 7 hp briggs and it is difficult to start. I rebuild/cleaned the carburetor and it is still difficult to outset.....about eleven y/o mower, I volition conform her valves and hope this takes care of her trouble; I too remember briggs as beingness an outstanding engine and promise this turns out to go on to exist the example.

Regards,

Brian

blmgtnman on May 27, 2015:

My passenger has been then hard to get-go these terminal 4-5 yrs. Information technology's like it has a dead battery every time I'd get out to try and get-go information technology. I knew the starter was good because it turns over hands without the spark plug. I've purchased iii battery'southward for this passenger and finally gave upwards two years ago after a shop charged me several hundred and didn't get the engine to plow over like it normally should. I so bought a self propelled toro to keep my lawn looking decent. My bad! I'm very embarrassed right now.

I came across your commodity and your tutorial worked exactly as you described! Now I feel so light-headed for not knowing I should be adjusting the valves on my Craftsman B&S 18.5 hp ohv intek engine every flavour. Because of you lot and your article, I will perform this process first matter every flavour!

And yep, I establish I needed to make several attempts adjusting the valves, but I eventually succeeded! The engine at present fires off immediately! I'k non an engine person and rarely if ever will I attempt something similar this. I'one thousand then glad I was fortunate enough to come up across your article! And if I may, my wife couldn't be happier that at 65 yrs sometime, I'm back in the saddle once again!

Yous Sir, truly are a precious stone and I wanted you to know! Many, many thanks!! Hope y'all have a wonderful day! Be well! Rick

Cardinal Fang on April 17, 2015:

I signed up here simply to say 'give thanks yous' for this neat, user friendly tutorial! I only saved loading up a zip turn mower & lugging it into town, so leaving it for x number of days and and then having them tell me (again!) that it's a 'weak battery'.

It took me maybe an hour, half of that time was just gathering tools & printing out the tutorial above. Outset hit of the key afterward doing this and it's purring like a rabid kitten on steroids. (Ok... and then I demand a beer.) Either manner - it starts like a dream and my original plan for this weekend was to weld up a total size motorcar battery tray... glad I took one final look online and found this page.

Thanks over again!

johng34 on September 25, 2014:

THANK YOU!!!

This was exactly my trouble, Briggs and Stratton nineteen.5hp. Just died during a mowing. The key for me was the high compression inkling. Put a new battery in it and it couldn't turn the engine over. Ii problems needed correcting before it would first.

ane) Exhaust valve rocker arm had 3/8in gap, due to information technology's mounting stud coming loose and backing out 3/viii".

2) Intake button rod, aluminum, bent. Don't know how it got that way, could be the steel cap on the top of the exhaust valve, when it fell into the bottom of the OHV well stuck in the intake valve on the mode downwards.

Installed new rod, loctite'd the stud back in, adjusted valves equally described herein. Started right upward. Put Kano Kreen in gas and oil, fabricated it sound MUCH amend right away. Going to prevent the input valve from sticking, which may have caused the bent button rod. Only 160hr on this 4yr quondam John Deere, that I bought used.

Thanks Once more, I've no thought how much money you saved me!!!!!

PK Jones (author) on January fifteen, 2013:

Hullo, I really tin't exercise diagnostics in this format. I'm non able to log in on a regular basis and this format just doesn't let for it. I can direct you to some other postal service I've made at the following link:

https://notice.hubpages.com/living/Why-is-my-eng...

It sounds like you lot have a a crankcase full of gas or a bad breather.

Chuck 1 on Jan 06, 2013:

My engine was hard starting but once it started ran skilful for ten mins. I turn upwardly the throttle and started off then it started smoking really bad. Fulled the garage with heavy smoke. and then died. I did not try to offset again. I took the valve cover off and it was total of oil and and air cleaner also had lots of oil. this is where I stopped. looking for answers to the trouble. One side of the valve cover had oil residue. What should I look for now????? i'one thousand thinking the head gasket and conform the valves. Anything else????

PK Jones (author) on September thirteen, 2012:

The feeler gauge to be used is the flat manner. The circular one would exist more difficult to concur in place when tightening.

The side valve engines do have a valve clearance procedure but it would exist more than I can explain in a curt annotate. Typically if there's a cam wear issue in a side valve engine, complete disassembly is required and replacement of followers, cam or valves is needed. Or you lot may get away with TIG welding material onto the valve stem end and machining to shape, but that'south also more than I can explain hither.

On the side valve engine, start with pulling the heads and cleaning the carbon build up. Also, you may have another issue than the pinch release, that would require a skilful bit of back and along and I tin't practice that here. Thanks!

cwatersjr on September 07, 2012:

Is there a way to bank check the valves on a xvi hp twin 2 NON OHV engine that is doing the same symptons as the orginal problem to a higher place. Starter will only tunr the engine partially. If you have the plugs out information technology spins freely. Any suggestions would be great..

cwatersjr on September 07, 2012:

Is there an adjustment on the valves when the motor is OHV? I take a BS 16hp Twin Ii that is having this outcome but is not OHV.

andrewharshbarger on September 04, 2012:

what type of feeler guess should be used when doing this or does it matter

PK Jones (author) on August 31, 2012:

Hullo, one time yous take the piston 1/4 Inch past TDC, you adjust both valves at the aforementioned time, no demand to motion the piston again. Now since this is a twin, you have to set the piston i/4 Inch past TDC before adjusting on each private cylinder. So you exercise i cylinder, then rotate the engine for the other cylinder and adjust it.

c- stanfield on August 26, 2012:

do you have to bring the piston to 1/4 past td. to adjust the intake valve then turn the engine again to conform the exhust. i accept a twenty hp. briggs vanguard twin cylinder. i adjusted them the other day and i made it worse. was my kickoff time. at 4-6 ths. simply i adjusted them at td. cheers for any help.

PK Jones (author) on December fourteen, 2011:

Robert is that the First part of the Family number or the Model number? If that'south a Briggs engine, the model number is stamped into the valve comprehend or on the sheet metallic.

Robert on December 13, 2011:

Whatsoever one know the valve lash on this model 2bu706 16hp ohv. I cant seem to discover it on the chart. I appreciate the assist. THANKS

PK Jones (author) on Dec 12, 2011:

You can change the spark timing slightly by irresolute the air gap of the scroll to the flywheel. Tight to the flywheel gives yous a piddling advance, farther away from the flywheel retards the spark. On a stock engine, gaining that trivial accelerate improves operation. On almost Briggs engines you lot tin can't dorsum the whorl up far enough to keep information technology from firing, but the spark may be late enough to cause difficult starting and make information technology run a little weak.

The position of the flywheel on the crankshaft is the primary timing. On a functioning engine we volition either use get-go keys to adjust advance or not even bother with a key and merely accommodate it co-ordinate to dyno results. The key is nothing more than than an alignment tool, it doesn't hold the flywheel in place, simply offset keys make adjustment easier.

You typically won't meet any reward to advancing the flywheel on a stock engine, but by tightening the ringlet to the flywheel you may. The gains are modest, but every little fleck helps.

billybob on December 12, 2011:

Ignition timing is keyed to the crankshaft and flywheel.

Robert on December 12, 2011:

When i ajust the coil to flywheel to.010 is this non the airgap ?

PK Jones (author) on December 11, 2011:

Robert, I'm afraid I cannot do diagnosis on this site. Merely, if this is a Briggs Intek engine, then utilise the link to the Briggs spec sheet, http://www.nnyparts.com/briggsspec.pdf, and cheque your model number against that nautical chart. The reason for using the factory adjustments is to prevent excess wear and ensure your valves are properly timed. Outside of the factory numbers, fifty-fifty by .001", will add together wear to the cam and rockers equally well as reduce performance. At .002" lash, the valves are opening too early and staying open too late, IF .002" lash is exterior of the Briggs specs.

This volition cause college fuel usage too as a loss of ability. On a 16hp engine yous may not easily discover the difference, withal put it on a dyno and yous're probably losing 1/2 to three/4 hp, which in a small engine is quite a fleck. Also air-cooled engines are very dependent upon proper valve and ignition timing for cooling and the prevention of carbon build-up.

For maximum performance on a stock engine, adjust the valves to the tight side of the specification and arrange your ignition timing by making sure that the gyre is no more the thickness of a dollar neb that'due south been folded three times. Past having the coil tight to the flywheel like that, you lot advance the spark past maybe a couple of degrees which improves the fuel fire.

Remember, the lash adjustments are to ensure the valves are opening and closing at the proper time on the cam lobes. Too loose on the valve that provides the compression release and you also volition either have no compression release or information technology will be reduced, causing unnecessary habiliment on the starter.

Robert on December 11, 2011:

I BOUGHT THIS ENGINE USED AND It IS 16HP ohv. WHEN I PUT THE ENGINE ON In that location, I CHECKED THE VALVE LASH.Information technology HAD VERY LITTLE.I couldn't even go a .002 gage to slide between the rocker and the pistom was up right.This engine is running proficient.Should i just information technology .004 and 006 what it calls for or leave it like information technology is? Kneed some help THANKS

PK Jones (author) on December 07, 2011:

Pitiful BillyBladez, I didn't mean for it to sound like you were Bob. Bob has used several dissimilar usernames to try and get posted and continues to try and brand insulting comments everyday. I was letting his posts without the name calling and insults through but plenty is enough. Good luck with your TroyBilt.

billybladez66 on Dec 07, 2011:

for the record pk, im not billy bob. I'1000 non gonna argue with somebody whose info saved my bacon and my dough. For whatever reason a slight adjustment to the formula was what it took for me. Had it not been for your posts, i would have been a sad sad pupy nearly my troybilt. You just keep doin what you're doin and i'll be happy to read what your doing...thanks to ya!!!!

La Purisima Golf Course on Dec 06, 2011:

Thanks to that. Small engine mechanic and was needing verbal specs.. Thanks Sick post 2morow and report results!!!

PK Jones (author) on December 05, 2011:

Bob, you said, "Y'all said in the end you adjusted the valves at .008 and .005 . What else did you detect wrong ? Your proverb that the engine was difficult to turn over. The valve adjustments beingness out that lilliputian wont make the engine hard to plow over." and and so y'all said, "Just for your information... .002 of an inch is less than a slice of paper. Not very much.

So you are directly contradicting yourself. You tin endeavour to recover by irresolute your story but y'all really need to accept that there is a proper procedure and that being precise matters. Information technology'due south most likely that you are not being precise and therefore aren't actually sure what your actual lash is.

This volition exist the final post of yours that appears on this folio no thing how many different names yous try to employ. I accept not allowed some of your other posts to announced because of your tone and am afraid that yous acquit the stardom of being the first I've had to do this to. This is not a forum to fence, information technology'south an information forum. If you would like to adapt your valves however you like, feel free. However Briggs has a particular method they experience should be used and they would tend to know all-time. I've explained why the valves are prepare the mode they are set up repeatedly and that'south not my recommendation, it is how Briggs designed the engines.

Attend a few Briggs training classes, and feel free to argue with them and endeavour to convince their Engineers they don't know how their engines are put together. I've been attention manufacturing plant small engine grooming since the mid-eighties and accept withal to find a reason to tell a manufacturer that they don't know how to adjust their valves.

billy bob on December 05, 2011:

Aye .002" would make a departure if the aligning was "out of specifications" similar for example .007" like your saying. Im non saying that though. What Im saying is I can suit the valves at .004",.005",.006" or anything in between .004" and .006" (which is a .002" divergence) and co-ordinate to the manufacturer they say this is fine considering these are the bodily specs. their recommending. What your telling me is this .002" difference is not acceptable. Tell me what you would gear up the valves at if the recommended specs. were between .004" and .006"

PK Jones (author) on December 05, 2011:

Recollect near it like this. Every bit the lobe on the cam turns and the lifter follows it, the lobe begins to lift the lifter. If your lash is too tight, the valve volition be opening early on the lobe's travel. If it's loose, information technology will open up late on the contour.

From .004-.006" is the amount of lash required to open up the valve at the proper time on the lobe. Add .002" to the gap and the valve volition open up many degrees subsequently on the lobe than if it were at .006". The lobe has a very sharp rise one time you enter the ramp then fifty-fifty .002" will be a big change. From .004-.006" in this case starts the valve opening at the proper betoken on the cam lobe.

Valve lash is an adjustment made to control the opening and endmost timing of the valves. The valves have to start to open and close within a narrow window on the cam's profile. Most people think valve lash is set up to control the total lift on the valve, only information technology's not, even though lift is affected. Information technology's all about the proper timing of the valves.

The manufacturer does say .002" makes a difference, attend any Briggs preparation school and they will cover clearances repeatedly. .004-.006" is the acceptable range in this instance. .007" would be out of spec.

billy bob on December 05, 2011:

Your missing my point. If the manufacturer is giving me specifications similar .004" .006" for the valve adjustments it ways a minimum of .004 and a maximum of .006 . When I went to school they told me there is a .002" difference betwixt those 2 measurments. Why is the manufacturer maxim .002" wont make a difference but your saying it will ?

PK Jones (author) on Dec 04, 2011:

.002" is enough to make a deviation when you lot are adjusting valves. Fix the intake lash at .002" when the engine likes .004" and most engines volition start popping every bit the intake begins to open several degrees early.

Valve lash is virtually when the valve starts to open. As well loose and the valve opens late, besides tight, the valve opens early. This is why about people have to endeavor several times before they get it right. The reason you lot plow the engine 1/4" by TDC is because of the cam's contour. This is how Briggs designed the system, and how the valves on these types engines are adapted. The slight ascent in the profile that creates the compression release does habiliment which will alter the measurements, which is another reason why you adjust at 1/four" past TDC.

billy bob on Dec 04, 2011:

If .002" is going to make a difference why are the specifications between .004 and .006 ? These specs mean your adjustments tin can be either .004 or .006 or annihilation in between. Which is a .002" divergence. This is why I set mine at .005" Information technology runs fine.

billy bob on December 04, 2011:

I think your referring to .004 and .006 equally being the limits. .004 beingness the smallest and .006 existence the largest setting. Similar I said earlier... I adjusted both valves at TDC to .005" (middle setting) and the followed your proceedure of turning the creepo another ane/4 " past TDC and my original settings of .005" were the same. I plant no divergence.

PK Jones (author) on November 30, 2011:

.002" is plenty to brand a deviation with the compression release. Although setting the valves tight is preferable to loose for performance issues. That said, not all OHV Briggs engines use the .004 and .006" specs, only well-nigh. I wrote this referring to Lawn Tractors specifically, which when having OHV Briggs engine, will have Intek engines 99% of the time and use the .004-.006" lashes. If in incertitude, just refer to the Briggs chart at this link, http://www.nnyparts.com/briggsspec.pdf

baton bob on November 30, 2011:

Just for your information... .002 of an inch is less than a slice of paper. Non very much.

billy bob on Nov 30, 2011:

You said in the end you adapted the valves at .008 and .005 . What else did you detect wrong ? Your saying that the engine was hard to plow over. The valve adjustments being out that little wont make the engine hard to turn over.

billybladez66 on November 27, 2011:

great mail service. Had to endeavour information technology nigh iv times earlier i finally made progress. In the finish i wound up setting the frazzle at .008 instead of .006 and the intake i ready at .005 instead of .004. After setting it this manner my flywheel finally purred over nice and polish without the help of a jump start from the trusty F100. This is something i will brand sure to go on on center on from now on. Btw, on my troybilt (2002, 18 hp ovc) my exhaust valve was on superlative as i faced the engine. I could tell because the frazzle pipe was attached at the summit, to the left of the valve, and so i assumed it to be exhaust.

robare15 on Nov 19, 2011:

I had the aforementioned problem with my 16.v Hp Briggs engine.

The instructions here are splendid and helped me solve the problem.

However, not earlier frying a starter motor.

I bought a new starter from dbelectrical.com ($43)and my tractor starts like new.

PK Jones (author) on November 15, 2011:

My statement reflects that if 1 valve is completely open, then the other valve would be at the same position every bit it would be at TDC, meaning it would be closed. Not that both valves are completely open. The inherent problem with using this method on Briggs engines is that the valve needs to be in stage on the cam with the piston 1/iv" by TDC. The method of adjusting valves with ane fully open and adjusting the other valve is an old method used on many pushrod engines. You simply bring one valve fully open, stone the crank back and forth to find the loosest spot in the other valve'due south lash and so adjust. Then repeat for the other valve. People have been using this method for decades on all sorts of engines, works pretty well for multi-cylinder engines when yous don't have a book to tell you what cylinder corresponds to the other.

Frank on November 15, 2011:

This is what yous've stated..."Having ane valve completely open would accept the other at the same position." Its impossible to have both valves "completely" open. Unless theres a trouble with the engine timing.

PK Jones (author) on November 08, 2011:

On the Briggs engines information technology's important that you are across Acme Expressionless Center and have the cam at the right position, which is the reason for going 1/4" past TDC. Using the method you mention, it would exist hard to know just where on the cam'southward profile y'all are. Having one valve completely open would have the other at the same position as at TDC so you would have to try to cistron that in on each valve. Not that information technology couldn't work, just that the method in the article is the easiest way and insures both valves are adjusted in phase.

kandk920 on November 08, 2011:

I take also seen the valve lash adjusted by rotating the engine until one of the valves is completely open, then adjusting the lash on the valve that is closed, so repeating for the other valve. How is this unlike than the method you explained? Thank you

PK Jones (author) on October 17, 2011:

Howdy, I can't do diagnostics on this site due to an agreement with another site and the format of Hubpages really doesn't allow well for it anyway. I volition tell you that the muffler glowing red is probably an overly lean condition in the carburetor. Pull the spark plug and it's probably gray and ashy. This would hateful yous have a carburetor that needs to be rebuilt or replaced most likely, although an air leak could besides cause this. In that location are a few other things that could be responsible but that would require more than indepth diagnostics and I just tin can't do that here. A carburetor issue would be the nearly probable though.

If yous look at the intake manifold, yous should be able to see that it is in line with the intake valve, same for the exhaust valve and the frazzle manifold.

Bob on Oct 16, 2011:

Sorry Nick. The intake is usually larger and exhaust is normally smaller. The valve your describing on the meridian , is the intake.

Bob on Oct 16, 2011:

Hey Nick. The intake valve is usually smaller and is in the block closest to the carburater. The frazzle valve is usually larger and in the block closest to the muffler. When your asking if the valve is closest to the superlative... Im gonna say your describing the intake valve.

nick on Oct 16, 2011:

Hello,New to this only how do you know what valve is the intake and what valve is the exhaust?Is the valve closest to the superlative of the engine the intake or exhaust?

Thanks,Nick

Bob on October 16, 2011:

The muffler was glowing red on my old Briggs. Is this considering the valves are out of adjustment ?

PK Jones (author) on September 17, 2011:

Thanks!

Jerel on September 17, 2011:

Hey in that location, I am a fifteen yr veteran automotive technician with much experience in pocket-size gas engines. I had never ran into this one and the post helped a bunch.

dave on September fourteen, 2011:

Finally someone explains why information technology needs to exist ane/4 by TDC.

I've always been curious.

PK Jones (writer) on September 12, 2011:

Hi, I can't actually diagnose in this forum. If the engine is still difficult to turn over so y'all may have another issue or even a worn cam. It would require a good chip of back and forth to piece of work through information technology and I'm only not able to do that here. Thanks, PK.

Joe on September 12, 2011:

I adapted the valves to .005" at TDC and then checked the valves a 1/4" past TDC and there was no difference. The engine runs fine.

PK Jones (author) on September 12, 2011:

The valve stems shouldn't have whatever lateral motion, merely up and downward. If the valves are moving around side to side, then the guides are probably bad and caput replacement is the best fix.

Jack thursday wack on September 11, 2011:

I volition try your procedure. My initial problem was a cleaved push button rod. I put information technology all back together but it simply ran for a infinitesimal. . . Roughly at that. Ane Q though; The valve shafts are grooved circumferencely. If the valve shaft is supposed to be locked in and move only inside a certain range, is it possible that they tin can motion out of place within a range of travel resulting in a gap so broad it can't exist adjusted to spec.? The rocker arm then flops around all over the place. More than subsequently I attempt the valve lash adj. Thanks for your help.

(Engine is a B&Due south model 310707, type0136-E1, 16HP Sears riding mower)

Pecker on September 03, 2011:

Thanks for the tip. I replaced the caput gasket on my craftsman lawn tractor, and afterwards it was hard to start with the symptoms you lot described. Did the process, and information technology works like a champ. Hardest part was finding a feeler approximate. (Went to Walmart and Ace before going to an Auto parts shop).

PK Jones (author) on August 31, 2011:

The way the camshaft is ground requires you to move the piston 1/four" past TDC so that you accept an authentic lash. Adjusting at TDC on many Briggs engines will give yous too loose an adjustment. Other makes, and some Briggs engines, tin can be adjusted at TDC.

Joe on August 29, 2011:

Why do you have to go along to move the piston another ane/iv of an inch past TDC ? Is this modest motility going to make a difference ? Thanks

dakota on August 12, 2011:

My mower started doing this very exact thing this week. I went thru the entire electric from battery, sol and removing starter to test it. Removed plug engine spun fine, replaced plug and every bit soon as it striking pinch it stopped. I tin can bound it with a jump box it does fine. Tomorrow I will do the above to the letter I volition let you know. Thank you for your commodity. I feel sure its this.

Todd on July 30, 2011:

This is then true. Ive been edifice motors for my tardily model for 18 years and winning on good nights. Never thought my 14.v BS had a valve lash effect. Ive been starting it with a jumper box all f north yr. 20min an information technology is dorsum like new. I used a pencil for the TDC -one/4 worked great. Thanks saved me buying a rider. One time a rain out at all 3 tracks was worth it.

Mike Eastward. on May 15, 2011:

give thanks yous, Exactly the problem .

PK Jones (author) on Apr 13, 2011:

Glad it helped you. Call back to include valve adjustment equally an annual maintenance item.

J. Westward. on Apr thirteen, 2011:

Have had starting bug with my Sears riding mower for over 2 years. Last summer (2010) paid some small engine "expert" $180, and he replaced the starter and bombardment. Same problem after he left.

Saw your article and tried it. Had never adjusted valves on any type of engine. Took me a few tries to "get the feel" of what I was doing, but finally put the valve cover back on and gave it a try.

ENGINE STARTED IMMEDIATELY AND CONTINUES TO Practise SO. Thank you very much for your valuable info.

Al on March 01, 2011:

That did it! Intake valve adjustment was .oo6" instead of .004", once adjusted correctly it made all the difference in the world.

Give thanks you for posting!

Marker on January 29, 2011:

The engine on my Craftsman lawn tractor would only creepo once and not get-go. I was thinking it was the starter merely establish your commodity, followed the steps, and it started correct up. Thank you.

PK Jones (writer) on October 22, 2010:

Glad it was of some help. It's surprising the number of shops which fail to take hold of this one.

Marker on October 15, 2010:

Thanks a ton. Brought my Rider in twice to have the issue looked at. They just kept telling me the battery was bad. Information technology took me xv minutes start to finish and the engine starts and runs similar a summit. Yee Ha!

PK Jones (author) on June 12, 2010:

Hi, aye, the engine needs to exist at 1/4" past Top Dead Center (TDC). At TDC, the intake valve has just airtight and the exhaust has non begun to open. The piston must be at 1/4" by TDC, so be sure to follow the instructions above for how to notice that spot.

D.J. on June 11, 2010:

does the piston demand to be in aforementioned identify for the intake and frazzle valve to be adj.?

PK Jones (author) on April 18, 2010:

Thanks! I'm glad it helped.

Pdemps on April eighteen, 2010:

Thank yous, very helpful and relieve me $$. I appreciate it, best written article on the field of study I could find.

PK Jones (author) on April 03, 2010:

Thanks for reading information technology.

electricsky from North Georgia on February 27, 2010:

Thank you for your commodity

durochermovenciought1948.blogspot.com

Source: https://dengarden.com/landscaping/Hard-to-start-Briggs-and-Stratton-engine

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