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Compression ???

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Old Feb 3, 2009 | 02:42 PM
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Default Compression ???

I wanted to check the compression in the motor and was wondering what kind of compression should I have for an 80cc motor?
 
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Old Feb 5, 2009 | 09:42 AM
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Default Compression ???

Anyone?
 
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Old Feb 6, 2009 | 09:07 AM
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Default Compression ???

I suspect the reason you did not get a response is your question is like asking how high is up.
There are tons of variations on this question. Even where you live makes a difference!!!!

Is it a two or four stroke?
Does it have an aftermarket piston in it?
Does it have an aftermarket cam in it?
Is it ported? (two stroke)

As you can see, there is a lot of questions to be answered before anybody can even begin to answer.
 
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Old Feb 6, 2009 | 11:47 AM
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Default Compression ???

Its an 80cc 4 stroke. Looks to be pretty stock. I found it on the side of the road where someone was throwing it away. I spoke with the owner and he said the motor was shot and no good. I took it home and cleaned the carbutrator and the thing fired right up. Its sounds and runs really good at idle. Its doesn't smoke at all. But when I go to give it gas, it boggs downs and wants to cut off. I dont think its the compression but I just wanted to be able to check it so I could elimenate that as a problem. I've taken out the spark plug and put me finger over the hole and it feels like it has good pressure but I know 60 and 80 psi would feel the same using my finger. I kind of wanted to put a gauge on it just to be sure that wasn't my problem. I've also removed the carb. and sprayed carb clean directly into the intake while cranking and it will run and rev up really high.
 
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Old Feb 6, 2009 | 11:50 AM
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Default Compression ???

Oh yeah, I've thought that it might be the mixture screw but this carb. only has one screw to adjust. I've started all the way from 1/2 turn out from the bottom all the way to its complete out and it still runs the same. Runs fine when idling but as soon as I give it gas, it boggs down and wants to cut off
 
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Old Feb 17, 2009 | 01:59 PM
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Default Compression ???

Identifying the motor or machine would go a long way towards getting some answers, but in leiu of that I'd expect at least 90 psi but probably more like 120-140. That's just a pure guess, but if it's double digits in psi then I'd wager it's not high enough
 
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Old Feb 17, 2009 | 06:44 PM
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Default Compression ???

Sounds more like a carb problem to me
 
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