Riding Mower barely turns once and doesn't start

Rivets said:
If you have the exhaust valve set at .00, you will have problems down the road. That clearance is to small and will become even less as the valve heats up and expands. Air bubbles in the oil were caused by running with the valve cover off.
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Thanks for confirming my bubble-assumption.

I have the exhaust valve at .03 (not .00) ... do you still think that is too tight and I need to back it out a bit again? (sniff ... but it ran so good - and I ran it for about 1 hr, mowing)
 
This has been a very informative thread but I need some information to clear my ignorance. On the youtube valve clearance setting, it mentioned top dead center check. I know what his is but don't know how check. Any simple expalnations?
 
Jeep Man said:
This has been a very informative thread but I need some information to clear my ignorance. On the youtube valve clearance setting, it mentioned top dead center check. I know what his is but don't know how check. Any simple expalnations?
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A safe rule of thumb for me is to go a tad "past" TDC. In that way you know for certain that the lifters/pushrods are on the low side of the cams.
 
Jeep Man said:
This has been a very informative thread but I need some information to clear my ignorance. On the youtube valve clearance setting, it mentioned top dead center check. I know what his is but don't know how check. Any simple expalnations?
Click to expand...

In a four-stroke engine, top dead center (TDC) is the point in the cycle right between the compression and the the power stroke. At that point, the intake and exhausts valves are closed and the piston is the closest to them (simplified).

In a single cylinder engine, to find TDC you could just turn the engine and watch all valves close, and right before the exhaust valve opens again, stop and turn back a tad. ...

If you've watched the YouTube video and liked it, I suggest, also checking out his 1st part of the video which shows how to do this with the help of a screwdriver in the sparkplup-hole (tells you the piston is up) ... just be carefull now to damage your piston/cylinder (easy does it):

Part 1 of the Video

Hope this helps ...
 
Just a quick note that some engines, and I can't remember which ones, but when you are exactly at TDC, the auto compression release could still be a little engaged and is why I find it best to go a little past TDC just to be sure the valves are "completely" closed. You are on the low side of the cam from a tad past TDC to the bottom of that stroke, so you have a lot of tolerance and no need to be that precise as long as you are within that down stroke
 
chance123 said:
Just a quick note that some engines, and I can't remember which ones, but when you are exactly at TDC, the auto compression release could still be a little engaged and is why I find it best to go a little past TDC just to be sure the valves are "completely" closed. You are on the low side of the cam from a tad past TDC to the bottom of that stroke, so you have a lot of tolerance and no need to be that precise as long as you are within that down stroke
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I haven't watched video mentioned by Hauker yet but I intend to. I was thinking earlier if I put a dowel or pencil through the spark hole and watch for limit of extension, I should be able to get a close TDC.
The closing of valves, I hadn't thought of. Thanks to all for the info.
 
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