shimshaggy250r

250r compression

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i just had my top end redone i have a 1988 trx 250r w/a 86 ported and polished cylinder and piston what should my compression be? the problem is my bike wont stay running after it gets hot, it did this 3 times, and each time it took less and less time.now it wont start at all. checked the stator and it appears to be fine as well as the cdi box, any help would be greatly appreciated....thx

shimshaggy

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I think it should be @ the 200-210 PSI mark, but I'm not 100% sure. It sounds like the CDI box to me. How did you check it?

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200psi is very high, you can't run pump gas with that high of comp. I'm pretty sure that it should be around 160psi, but I am not 100% sure on that. I would do a leak down test to make sure your crank case is sealed, if you have a leak some where, that could be your problem.

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Did you do anything "Aftermarket" to the Head after the Porting of the Cylinder???

Check this Chart out.....Specific for the TRX....The WORST thing you can do is Take the Advice of someone that isnt Sure of what they are telling you.....:aargh:

TRX250R Compression / Compression Ratio Chart

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It's Your Coil . After Yrs Of Ridding It Will Wear Down The Coil. The Coil Takes Power From The Stater And Amplyfies It So U Get A Hot Spark For The Spark Plug . The Coil Is Getting Hot And Leaning Out On Power From Years Of Riding The Atv. Also If U Plug Check Without Grounding The Spark Plug To The Motor Or Something Metal This Will Burn Your Coil Out! I Hope This Help U, Well Have A Good Day.

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