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xs650 > > Motorcycle Systems > > Engine > > compression test,170psi,too high?!


compression test,170psi,too high?!
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smearny
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Joined: Aug 13, 2009
Posts: 88
PostPosted: September 18, 2009, 1:58 pm    Post subject: compression test,170psi,too high?!
..i heard it should be 150max.but this is the 2nd motor i tested 170psi,both sides
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xsleo
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Joined: Oct 28, 2007
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Location: Earlville NY
PostPosted: September 18, 2009, 11:12 pm    Post subject: Re: compression test,170psi,too high?!
Mine was 165 after I rebuilt it. Thats setting on the bench and testing with the starter. The book calls for 145 on some , some years 138. I think thats just a minimum number. After the engine has run a few years and the carbon builds up, the compression builds up too. If you have the carbs tuned right and the timing is right I wouldn't worry to much about the exact number, run it a while and check it to see if there is a change.
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smearny
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Joined: Aug 13, 2009
Posts: 88
PostPosted: September 19, 2009, 1:46 am    Post subject: Re: compression test,170psi,too high?!
what do you mean by "carbs tuned right"?synchronising?!
i will check the idle,and what else?!
thanks
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xsleo
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Location: Earlville NY
PostPosted: September 19, 2009, 2:06 am    Post subject: Re: compression test,170psi,too high?!
Carbs tuned right means the right jets, air mixture screw, needle position, syncing. every thing right. the same with the ignition, points gap, timing, idle and advance. get every thing right or close to, run it awhile and see how it acts.
I've got almost 3000 miles and still fine tuning things.
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