compression test

[harley1-5]

I know this is a rookie question but should I be performing my comp test with engine warm I allways have before.i tried it on my blasty cold and at 90pnds I am in trouble if no difference

 

[Herpderplol]

It shouldnt make any difference, yeh 90 is low...

 

[Quadman1]

I do mine when cold, and doesn't it have to be 120 to start?

 

[harley1-5]

that's what I figured and yea I knew 90 was low so I guess top end time soon

 

[Herpderplol]

120 is good, you can start engines on low comp though

 

[bansheedave]

Just remember, you have to have the throttle full open while doing a compression test on a 2 stroke.

 

[harley1-5]

yea I knew they would start on low comp ive just done it hot if possible even when I worked in a small engine shop I did comp test on warm engines.it still performs well too.but rather than do more damage I think im gonna wait till I can afford it and do the top end maybe in march or so when taxes come I want it done right so when the income tax fairy comes ill spend with ken for machine work and parts

 

[harley1-5]

i did bansheedave but may try again tomorrow

 

[Larry's Shee]

Consider trying another tester. If schrader valve is at gage rather than end it will read low. Also, cheap gages are notoriously low, as are rental gages.

Have you done a leakdown test? Leaking head gasket might also give low reading

 

[harley1-5]

gonna do leak down test tomorrow after work is a cheap gauge do you think being warm will make a difference?

 

[Awk08]

gonna do leak down test tomorrow after work is a cheap gauge do you think being warm will make a difference?

i've seen reports of only +5 psi warm versus cold

 

[harley1-5]

thanks awk may just have to put the blasty away for a few months

 

[harley1-5]

went out before work found leak in comp tester fixed leak and now I have 120 psi

 

[Awk08]

went out before work found leak in comp tester fixed leak and now I have 120 psi

woohoo....tax $ for other parts I:I

 

[harley1-5]

no tax dollars for some bikes to flip to stretchhhhh $$$$$

 

[harley1-5]

well gonna def need a top end I can reach through exhaust port with my finger and move piston from side to side not good

 

[Herpderplol]

Probably just a hone and new piston+rings

 

[harley1-5]

its got a good bit of play guess ill go up to next size piston and try to do the diy port it from kens videos

 

[Herpderplol]

Perfect I:I

 

[harley1-5]

wiseco top end kit only $98 on ebay cant afford it but I will figure out how to get it gotta find out how much a bore & hone costs