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Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 8:08 am
by tom waite
bakaracer wrote:are you reusing and old head gasket? did you torque the head bolts to spec?
The head gasket was new upon rebuild. I keep tossing it back in because I am taking the head off several times. I'd have to have a stack of headgaskets if I wanted to put a new one in each time. I have been torquing the bolts.
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 10:02 am
by Bear45-70
Reusing an old head gasket is ASKING for trouble. Being cheap only cost you in the end.
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 11:43 am
by jbarb
Quick question about compression tests:
If you have like 80 lbs DRY with WOT, but it boosts to say....100 with a little 2 stroke oil down the plug hole, that motor would be considered to have crappy compression? Those were the readings i got off my spree that would never run right. May have been more like 60 or 70 dry.
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 3:02 pm
by bakaracer
Yeah pretty much. That's time for a rebuild right there
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 3:13 pm
by evilone
Marks on the rings need to face up on the piston.
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 8:36 pm
by tom waite
Bumpdate:
Rings were upside down. I wasn't looking in the right spot for the "mark". Bad news is I busted the Jug base gasket doing the rings. I made a gasket for it but the material was atleast 3x thicker. My results were 95psi. I'm not to familiar with how much of a difference the gasket thickness makes on CR, but I know a little bit goes a long way. I very well could be losing 75psi from it being too thick.
So I put the old broken on back in. It was only severed in one spot. The rest is intact. I figured I had nothing to lose. With the broken OE gasket I got 89-90psi again. I also checked the head and jug for warpage. Both were straight as good be. I used T square and a flashlight as suggested.
Tomorrow I will go on the hunt for a new base gasket, and head gasket. Do you guys honestly think I am two gaskets away from proper compression?
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 9:02 pm
by PimpinSpree
Not really. You should just do it right and get new gaskets, new rings and get the cylinder honed. You'll end up having to do it anyway, so just save some time
Re: I now have compression and it still won't run:(
Posted: Wed Jun 29, 2011 9:04 pm
by bakaracer
yeah get new rings if you ran it upside down. the new stock gaskets will help for sure. before youget new rings, measure the ring end gap of the rings you have now and see if its within spec. if the gap is out of spec, that will give you a low compression reading also as you will loose compression pass the ring ends.
Re: I now have compression and it still won't run:(
Posted: Thu Jun 30, 2011 9:13 am
by tom waite
I need new rings too? They are brand new. The cylinder was honed before install. Are you guys saying hone it again? There has to be another issue.
Re: I now have compression and it still won't run:(
Posted: Thu Jun 30, 2011 9:02 pm
by bakaracer
tom waite wrote:I need new rings too? They are brand new. The cylinder was honed before install. Are you guys saying hone it again? There has to be another issue.
check the ring end gap on the rings you have now. if its to big, that will be one of the reasons why your compression is low.
Re: I now have compression and it still won't run:(
Posted: Thu Jun 30, 2011 11:32 pm
by tom waite
bakaracer wrote:tom waite wrote:I need new rings too? They are brand new. The cylinder was honed before install. Are you guys saying hone it again? There has to be another issue.
check the ring end gap on the rings you have now. if its to big, that will be one of the reasons why your compression is low.
will do.