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.



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

  1. 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 !!!

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

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