No Compression

bertsmobile1

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First thing is to rotate the engine 2 full cycles with the rocker cover off and watch the valves moving
Both valves move the same distance & sit the same distance out.
A rookie mistake is to set the valve lash on the exhaust stroke, not compression stroke which will cause zero compression
 

slomo

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Or thinking the EX valve is the intake, LOL. I caught myself once doing this like an idiot.
 

Scrubcadet10

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So you don't try to determine compression stroke or exhaust stroke?
I never have.... one valve open (which means that rocker arm will be pushing that valve spring down) adjust the other valve. Repeat the process.
 

Hammermechanicman

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So you don't try to determine compression stroke or exhaust stroke?
No need to. All you are wanting is to adjust the valve while the tappet is on the base circle, or heel of the cam. If one valve is completely open the other valve is closed and tappet is somewhere on the base circle of the cam. Doesn't matter where. Same for the other valve. Only engines i use a timing mark to position flywheel are the stihl 4mix engines.
 

StarTech

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No need to. All you are wanting is to adjust the valve while the tappet is on the base circle, or heel of the cam. If one valve is completely open the other valve is closed and tappet is somewhere on the base circle of the cam. Doesn't matter where. Same for the other valve. Only engines i use a timing mark to position flywheel are the stihl 4mix engines.
And that because they use the same camshaft lobe, just they didn't need a special .004 feeler gauge as I can lose it every so often. I finally got another replacement but I am still awaiting the octagon adjustment tool. I have been lucky so far as to not need it but I know I will.
 

lbrac

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At TDC on the compression stroke, both valves will be closed (on their cam base circles). This is normally the proper position for adjusting the valves. I usually remove the spark plug when troubleshooting with a cool engine and put my finger over the plug hole while manually turning over the engine. There should be pressure on the compression stroke, and vacuum on the power stroke, with both valves closed, except near BDC. The exhaust stroke will have very slight pressure with the exhaust valve open until near TDC; and the intake stroke will have a very slight vacuum when the throttle is closed and the intake valve is open until near BDC.
 

jagg2236

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My Briggs and Stratton 11092-0113 f1 single cylinder overhead valves has no compression. Replaced head gasket,seated and adjusted valves. Was wondering if I need to replace the camshaft? Would the camshaft cause me not to have compression?
My 2cyc Husqvarna 350 chainsaw goes through pistons & cyl every year. With that said pull the head, check/replace the exh valve, check the cyl wall for scores. Replace the cyl & piston. BTW my problem might be I've been replace my cyl/piston with cheap "China" ebay stuff. Next time I'll get OEM. Whole other Husq parts subject???
 
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