Ive got some running mopeds but how does one go about testing their compression?
compression testing
Re: compression testing
Thread in the tester, hold the throttle grip WOT and kick it over a few times.
Re: compression testing
into the spark plug hole right? WOT? is a tester costly?
Re: compression testing
Yes, it threads right into the spark plug hole. Mopeds have a 14mm spark plug hole. "Wot" is wide open throttle. I think sears or most auto parts places have ones around $25-30. You could probably find them cheaper if you search around. There are two types, a thread in and a push in type. The thread in type is best.
Re: compression testing
will it also gauge top dead center?
Re: compression testing
no
Re: compression testing
Re: compression testing
You could buy or borrow one like this!
Re: compression testing
can someone please explain why you are suppose to hold the throttle wide open?
people say this all day long, but it makes absolutely no difference in the final reading
Re: compression testing
I would think to make sure your getting fuel in there to make a nice seal with the oil?
Re: compression testing
"Something like this dial gauge will help with TDC":http://cgi.ebay.com/Machinists-Dial-Indicator-1-1000-Gauge-tool-Measure-Gag_W0QQitemZ120161766142QQihZ002QQcategoryZ20766QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
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