How to adjust valve lash on Briggs & Stratton 330000 series engine

How to adjust valve lash on a Briggs & Stratton 33000 series engine. This particular engine needed between .003 and .005 on the intake side and .005 to .007 on the exhaust side. Check your motor's manual to make sure you're adjusting the lash accurately. Furthermore, I initially created this video to address the problem of compression lock regarding B&S engines. Compression lock is mentioned several times during this video, but was ultimately NOT the reason this engine quit starting. The problem was a broken compression release mechanism on the camshaft which had to be replaced. However, if your valve lash is severely off, you might run into starting issues. This video will help with that. Otherwise, check out my other video series where I remove the engine and complete a cam swap. Cheers.

[@brianbitney1022]

Thank you so much. I watched two other videos and could not get this. They didn’t talk about watching for the top dead center after the exhaust cycle.

[@FastFixYouTube]

Hello. I’m glad this video helped then! Thanks for commenting and have a fantastic day. 👍

[@wendellanderson3208]

Great tutorial! Had the same problem with my engine - 17.5 HP Briggs & Stratton. Followed your instructions, and it worked perfectly. No more compression lock, and the engine runs great! Thanks for posting.

[@FastFixYouTube]

Glad this video helped! Please keep in mind the compression lock issue might also be occurring because of a broken compression relief mechanism that’s located on the camshaft. If this part breaks (which is common) the only way to fix the issue is to replace the camshaft. I have videos of that process should you need them. Thanks for the comment 👍

[@jenf1387]

You rock. I can't tell you how many videos I watched that show you how to get the valve clearance with the feeler gauge but you are the only one that shows you top dead center then a quarter inch back. I had to replace the whole head so I was kind of up shit's creek without this video. Thank you so much

[@FastFixYouTube]

Man, I feel your pain! It’s the main reason I started this channel. Cut the bullshit and just show people what they want / need to see. No one is perfect and if I’m honest, I could’ve done this video much better, but I’m glad you found what you needed with it. Thanks for the nice words. Much appreciated 👍

[@Dan-y9f]

Thanks bud, saved me from having to rake a ton of grass... Son had cross threaded spark plug after trying to fix a no start issues... When i pulled the head off the rods stayed in place..yada yada...anyway she's back up n running and the compression issue was the exact no start issue so 2 birds with 1 stone!

[@FastFixYouTube]

Fantastic! Always happy to hear this video saved a hard days labor 🤣👍

[@keithross4928]

Thank you for clarifying TDC and the 1/4" gap. I also changed the head gasket. Started first turn of the key!

[@FastFixYouTube]

Fantastic! Glad this helped. I appreciate the comment 👍

[@cwhyharris7473]

Thank you you did such a good job explaining this. I had replaced everything except I didn't want to mess with the motor, ( battery solenoid starter everything). Then I went out and bought the feeler gauge and that gasket after watching your video set them the first time and it ran. It was only two years old I didn't have the money to send it to a shop I'm a 63 year old female. I was so amazed and you gave such good information walk me right through it, thank you so much.

[@FastFixYouTube]

You are very welcome! These comments are the best to read. It’s why I started the channel. Thank you for posting your experience and the nice words. It’s very appreciated. 👍

[@XvXOutcastXvX]

Great video. Helped me out a lot, now neednto find a good video for tuning a carburetor lol

[@FastFixYouTube]

Glad this helped!

[@markjud1331]

Great video. I’ve read the comments, but want to make sure I understand be starting repairs. My 15.5 hp B&S engine definitely has compression lock. I used your starting fluid method and it worked great. But I want to fix the problem. Do I understand correctly that I should check the valve adjustment first and that may fix the problem? If it doesn’t fix it then go into replacing the cam shaft? Engine runs great after it starts. Thanks.

[@FastFixYouTube]

Hello. Yes, you’re correct. First, adjust the valves to spec. If that doesn’t fix things, look to replace the cam. 👍

[@markjud1331]

Finally got around to working in it. Adjusted the valves like you said and she’s starting and run in like a new one! Sure was glad I didn’t have to open her up! Thanks, man!!!

[@keithshreve6736]

Excellent video. Thank you !

[@breannaoliver6316]

Fast fix gracias por TU explicacion biennn!!! Hecha te lo agradesco amigo!!!

[@FastFixYouTube]

You’re very welcome!

[@jimeronimo]

Hey pardner. Think we have the same motor331777-2372-G5 runs 15 to 20 min then dies and won't start. Think it's the coil. Replaced but need to confirm the armature air gap but can't find a spec sheet for this motor. Can you help a brother out. Is it .10 or different for this model?

[@FastFixYouTube]

Hello. I feel your pain on finding specs for these engines. Parts are hard enough let alone tolerances. It pains me to even think about…. Anyway, I found this video that says it applies for all models. Might give this a try. kzbin.info/www/bejne/a6GciISKnd-DaNU

[@jimeronimo]

@@FastFixKZbin thanks buddy. I was able to have a service rep email me. Confirmed its .08 to .14 so. .10 will work fine.

[@FastFixYouTube]

Excellent! I appreciate you reporting back with the information. Thanks!

[@robwright4398]

Nice car, looks like a fox body mustang.

[@FastFixYouTube]

Rob Wright it is! And thank you :)

[@Pjsev]

Doesn't that have a gasket? I am about to take my Bronco 42 apart and can't find a gasket for it...this might explain that! No wonder I can't find a gasket if it just uses a silicone seal!

[@FastFixYouTube]

Yup, exactly right 👍

[@pamwilson6999]

I set the intake at .004 and exhaust at ,006. The mower starts fine and idles biy when I engage blades the engine shimmys and loses power but doesnt die. should I adjust intake or exhaust? And to what? video helped was not starting without junp before. thank you

[@FastFixYouTube]

pam wilson hmm...doesn’t sound like a valve lash issue if the mower is dying when you engage the blade. Sorry for the stupid question, but is the engine at max rpm when you engage the blade? Engaging the blade at low RPM may be causing it to die. I would also check the drive belt (belt connecting the blade to the engine) and make sure it’s not getting snagged or hung up causing excessive load on the engine and causing it to die. Otherwise, it sounds like a power issue. I’d go to the carburetor if all other things seem okay. Carb might not be getting the correct air/fuel to the engine for adequate power or might be sticking closed or not fully opening. Best of luck!

[@pamwilson6999]

I engage the blade at the half way point on my throttle when I try to move the throttle more it doesnt respond it bogs down and shimmys and sputters. I never had the issue before i adjusted the valves because i had to jump it to get passed compression point

[@FastFixYouTube]

pam wilson if you already adjusted the valves appropriately, that part is done. I’d move on to the carb. Can you rev the engine to max rpm when the blade is disengaged? If so, the carb might be okay. Again, I’d check the belt connecting the blade to the engine. I’m not a small engine mechanic, so I can’t say for certain on this stuff. Just kind of giving you my two cents. Best of luck

[@matthewpiper1421]

And sometimes the compression release lever on the camshaft breaks off.

[@FastFixYouTube]

Yes, exactly! I’ve had it happen 3x…

[@SgtTonybertram]

Manual says to turn the crankshaft counter clockwise.

[@FastFixYouTube]

Yes, you can do that.

[@sidneywhite749]

I have the 19.5 engine, series 31p. I am confused which is exhaust valve and which is intake. My specs call for 5 in and 7 exhaust also but our engines ate different.

[@FastFixYouTube]

sidney white hey there. A good rule of thumb to use is the intake valve will have an aluminum push rod and the exhaust will have a steel push rod.

[@biker197471]

The intake will be on same side as plug exhaust is on side with exhaust pipe.

[@thepatriot4355]

I have the Craftsman T240 with the Kohler KT725 22 horsepower 725cc V Twin Engine 7000 series its built like a brick house

[@FastFixYouTube]

That’s awesome! The B&S suuucks…

[@thepatriot4355]

@@FastFixKZbin Agreed it's a shame Briggs and Stratton at one time was the go to Engine today its Kohler or Kawasaki

[@dansofi]

Hi,can any one help me with hard start , B&S 21 hp ,I set the valve clearance but no change starter can not turn the Engine freely, but if I keep trying it will heat the starter & sometime with not full rotating start right up ,I changed Battery,Starter . Engine ran before with Low & dirty oil--But no knocking when running & after 1 hour of cutting grass when I shut this ,it still hard for starter to move the Engine . Too much compression or any part bend in engine?? Thanks

[@golfergears]

Had that problem once, the start relay contacts were not making good contact. Cleaned the contacts up. Pop rivet the relay back together and it crank a lot better. That held me over until I got a new one. Might not be your problem but could be.

[@hdrjunkie]

Jut doing mine, same engine... it was the crank shaft. There’s a little cam type piece on it that acts as a compression release to make the valve open a little when your starting it then after it starts, the force of the spinning can shaft makes the little cam slide out of the way so the valves work as they are supposed to. Well that little cam wears out and breaks so you have to replace the cam shaft with a whole new one ( abut $60.00) on Amazon dot com. It’s a surprisingly easy and fast fix though.. about an hour to remove engine and take out the cam and put back together... I’m just waiting to get the cover gasket in!

[@dansofi]

@@hdrjunkie Thanks yes I found that last Season & Fixed it--Thanks

[@dansofi]

UPDATE--I fix it -changed the Camshaft with release vale mechanism--Thanks everyone

[@armyvet4081]

You should set both at .004.

[@FastFixYouTube]

Jerome Cook You could do that and be fine, but I like to shoot for the middle of the tolerance range. Thanks for the suggestion.

[@mikeeveans4355]

you don't know how many hp motor you have this is useless unless we know how many hp the engine is

[@FastFixYouTube]

I don’t? Hmm, it is written on the case of the motor, but numbers are hard and who has time to check.

[@ghorn3136]

YOu should DELETE this video because it MISLEADS from the very beginning…. This is NOT a “COMPRESSION LOCK” due to valve misadjustment. It is a FAILED CAMSHAFT COMPRESSION-RELEASE MECHANISM…and the Fix is to replace the camshaft. about 3 hrs for a handy guy with a set of sockets.

[@FastFixYouTube]

You should DELETE this comment IMMEDIATELY because it fails to take into account the EXPLANATION I wrote in the DESCRIPTION.

[@BM205]

@@FastFixKZbin 😁man it wouldn't be a comment section without "that guy". I'm headed out to the shop now to see if it's valves or comp release for me. I haven't adjusted valves in a while so I watched your video as a refresher course and it looked good to me.

[@jdras3]

I would like to add something .... the reason for the extra 1/4 inch of travel is to activate the compression spring release ....after the intake valve closes there is a quick opening and closing of the valve again, if you dont see that action it's a good bet the spring or counter weight on the camshaft has broken and is not operating making valve adjustment useless. Then a camshaft replacement is needed- not a bad job to do but it can be a little intimidating. I know this is an older video and I didn't watch all the way through so you may have mentioned this but I am having that issue at the moment with two B&S motors and have watched a ton of videos to piece it together. I hope this helps !!!

[@FastFixYouTube]

Joe Drasal III yes! That was the exact issue with this motor. I adjusted the valves in vain... the compression release mechanism had failed and prohibited the engine from turning over. After I did the valve adjustment I had subsequently released the pressure in the cylinder and the motor fired up after I had completed the job. A sure sign to me that the fix had worked. But the 2nd time I tried to start the motor, no dice. It took me a while to figure out the problem, but ultimately I discovered the issue. I made a couple videos detailing the camshaft repair, but thought this video would be helpful to those who did in fact have questions about valve lash adjustment. Thanks for the comment and best of luck with those motors!

[@billshedd55]

Rotate the engine until one valve is fully open and then adjust the other valve. When one is open, the other is closed. No need for finding TDC.

[@FastFixYouTube]

William Shedd yes, that is correct. I wanted to show the exact procedure according to the B&S manual so as to most accurately document the procedure for the new-comer that might be afraid of taking “shortcuts.” Thanks for the comment!

[@oldmandoingstuff8997]

Tks b. Shedd helped this 64yo shadetree get to the readers digest

[@exinanition2307]

Blueoyster5, I wish you well, sir. I would like to comment, if I may, about some information you gave in your video. You said the intake valve lash should be set at four ten-thousandths That would be .0004; however, it should be set at .004 which is four thousandths. Perhaps this is what you meant but for the sake of your viewers I wanted to point it out. Also you said you did not have a .004 feeler gauge so you used a "three and a two and a half." That would be five and a half thousandths which is in range yet still a bit large for the intake, seeing that too great a valve lash is what causes the compression lock in the first place. Just for the sake of information, you can set either valve lash as long as the opposing valve is wide open. That way you do not have to mess with the dowel or with finding a quarter inch past TDC. I wish you a blessed day, sir.

[@FastFixYouTube]

Hello Exinanition. Good catch on the "ten-thousandths" comment. I did indeed mean "thousandths." If only KZbin allowed me to edit these after they were posted I would certainly make the adjustment. Thanks for letting all the viewers know. I very much appreciate constructive comments like this one. They help make KZbin a better place I'm not sure if you read the description, but the valve lash ended up not being the reason for the compression lock. The compression release mechanism catastrophically failed and was causing the issue. I address that problem in another video. And yes, you're correct. As long as the opposing valve is wide open (and assuming there's no overlap in the valves) you can set lash. In my video, I was following the B&S instructions on setting valve lash so as to "ease" the mind of new comers to engine work that might otherwise see alternative methods that didn't follow exactly what B&S recommends as proper lash setting procedure. Again, I very much appreciate your comment and have a great day!

[@vinceg362]

Great video. I’ve watched a half dozen about adjusting intek valves and this is the only one that explains how to add the quarter inch. The wood dowel rod is exactly what is needed for us shade tree mechanics. 👍

[@FastFixYouTube]

Vince G and that’s exactly why I made this video. Glad it was of use to you! Thanks for the comment.

[@45tyable]

Thank you so much for this. I got it running and the yard is now mowed.

[@FastFixYouTube]

You’re welcome!

[@oldmandoingstuff8997]

Tks fast fix guy for thkin time to video. Ive the exact problem.

[@FastFixYouTube]

Yes sir, seems to be a common theme. If adjusting the valves doesn’t help, likely a failure for the pressure relief mechanism. Got a video on that too if so. Hope you get it going!

[@jenf1387]

This video saved me from sailing shit's creek without a paddle again. This 19hp engine is garbage. This time the push rod bent and head gasket blew again. Lesson learned.....don't buy aftermarket parts. Got the timing right on the first try this time. Thanks again.

[@FastFixYouTube]

You’re welcome! We share the same feelings regarding the motor. If electric wasn’t 5k, I’d go that route in a heart beat.

[@jenf1387]

@@FastFixKZbin I agree. For that price I'll just replace the head gasket every year. Thanks to your video the hardest part is pretty damn easy.

[@jenf1387]

@FastFixKZbin my words are coming back to bite me, saying I'll just replace the head gasket every year. Well it's been about a year and you're about to bail me out for the third time. It blows in the same place every time the thin strip next to the push rods. This is a Craftsman riding mower and between the engine design and the genius engineering idea to put the exhaust in the front of the mower so it blows in your face the whole time it's almost laughable at this point.

[@thomasfleeman4250]

I have learned don't worry about TDC just get one valve at a time totally open and set the closed valve very easy

[@FastFixYouTube]

Yes, true enough. It’s not a race motor, so…

[@Serpico1152]

Great video and explanations I think it's the best one on KZbin as you have the same good work ethic as I was taught to follow! I've been mechanical my whole life and finally decided to check my same 21hp model Briggs and Stratton's valve lash after 8 years and approximately 800 hours. They were at .009-.010 not too noisy or giving me any issues so I adjusted them likewise at .004 intake & .006 exhaust 1/4" past TDC using my wood dowel. I appreciate all your videos especially on the B&S engine and hope that I don't ever have to replace the camshaft compression release in the future, but I'll feel very confident if I have to by just watching your video.

[@FastFixYouTube]

Hello. Thanks for the great comment! Yes, work ethic of do things right (or at least attempt) and therefore not have to do it again. lol, sometimes that works, sometimes not. But that’s how we learn. I hope you release mechanism doesn’t break either. Sounds like you’ve got a keeper with 800 hours of service! Nice!

[@natester1064]

Great job thank you so much for your help! 👍👍👍

[@FastFixYouTube]

You bet!

[@leroywoolington1176]

Still hard to turn over for me

[@FastFixYouTube]

Hello. Is the starter able to turn the engine over? Or does it turn for a moment then freeze?

[@biker197471]

Ok I did everything exactly 1/4 “ past tdc intake 4 exh 6 tried 3 5 4 4 no luck . How can you tell that compression release is working. Pretty sure mine isn’t releasing.

[@FastFixYouTube]

biker197471 the big give away is if you’re able to start your engine by manually moving the piston to just after TDC on the compression stroke. To do this, remove the spark plug and spin the motor to TDC on the compression stroke. Place your finger over the spark plug hole while moving the piston. When you feel pressure, you then know you’re on the compression stroke. Continue to spin the motor just beyond TDC so there’s no compression left. Replace the spark plug making sure to connect the spark plug wire and try to start it. If the engine spins and starts you know you’ve got a bad release mechanism. If the engine spins, doesn’t start and becomes stuck, you know you have a bad release mechanism. Basically, the engine should spin freely. If it does not, probably a case of compression lock and a bad release mechanism. Best of luck!