# YS4500 And Flywheels



## sysiphus (Oct 6, 2015)

So, after reading through here, I got to the point where I found that my flywheel had sheared the key, and that it was what was causing my timing problem. Replaced the key no problem. Started the mower and it ran for about a minute before going off again. A teardown showed that the key was sheared again! It's the Intek Plus 21 OHV engine, and the valves were properly adjusted at the time the key was replaced. I have not checked yet to see if the little decompression nub (or whatever it's called) is working, but can anyone give any other reasons for it happening? 

Thanks


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## bbirder (Feb 26, 2006)

Did you put any oil or grease on the shaft? It has to be clean and dry between crankshaft and flywheel. If clean perhap you failed to tighten the flywheel enough.


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## sysiphus (Oct 6, 2015)

Thanks for the reply. No grease or oil on the shaft, but I can't say with certainty (after the fact) that I had the bolt cranked down enough.


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## bbirder (Feb 26, 2006)

That's why they are usually a little hard to come off, because they are torqued down quite tight.


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## TecumsehBriggs (Jun 17, 2011)

+1 on the flywheel torque. It's common that they don't always torque them properly at the factory.


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