Someone gave this mower to me about 2 years ago, and it's ran OK until recently. It's always been a bit hard to start, but always started. Now it won't start at all... when it turns, it hits the "hard" spot (I think this is the compression stroke?), stops, and won't do a 2nd turn. Doing research, I've found it's fairly normal for these engines to have compression release problems, and adjusting the valve clearance should fix it. I had never done this until searching this issue, and it didn't fix the problem. I just talked to the person who gave it to me, and he said in 10 years he had never adjusted the valve clearance even once. I'm assuming this can cause other problems?
Does anyone have any advice on what to do/check from here? I'd really like to fix it myself without having to put it in the shop.
If the valves are set at the proper .004-.006 clearance and still won't get past the compression stroke, it usually means the the compression release is broken, double check the clearances and make sure they were adjusted with the piston 1/4 inch past TDC compression stroke (both valves closed) If still no go, then sounds like time for camshaft change.
Thanks for the reply ILENGINE. That mostly confirms what my research has found. I didn't want to start working on things that aren't broken. I've never really worked on engines, but I'm ready to learn something new. If I'm going to have this thing, I may as well learn to fix it.
I will reply back here if I have any questions or to report success. Thanks again.
To check compression release function - After you have adjusted the valves at .004 and .006 insert a .001 or .002 feeler gauge between the exhaust valve stem and the rocker lever. I believe it's the exhaust valve that does it.
Now rotate the engine to the next compression stroke and if the release is working the feeler gauge will tighten when it is time for the release lobe to do its job as the piston approaches TDC but be loose again just after TDC.
