jrod Posted June 10, 2010 Report Share Posted June 10, 2010 Ok today i finally got my motor all put together. And i did a compression check, and it is about 10psi off? I am at about 140psi, and i have 20cc domes and a Aggressive dune port. I did the compression check by holding open the Throttle and having the pipes off the bike. I am about 1200 feetabove see level. Noss Website says i should be 150ish. Quote Link to comment Share on other sites More sharing options...
SLORYDER Posted June 10, 2010 Report Share Posted June 10, 2010 Ok today i finally got my motor all put together. And i did a compression check, and it is about 10psi off? I am at about 140psi, and i have 20cc domes and a Aggressive dune port. I did the compression check by holding open the Throttle and having the pipes off the bike. I am about 1200 feetabove see level. Noss Website says i should be 150ish. Perhaps your high exhaust port is the culprit. Having an aggressively ported cylinder willl cause your cranking compression to be low Quote Link to comment Share on other sites More sharing options...
Fastassbanshee96 Posted June 10, 2010 Report Share Posted June 10, 2010 I'm at about 150 with 19cc domes on stock cylinders and no porting. Quote Link to comment Share on other sites More sharing options...
pr0blumz Posted June 10, 2010 Report Share Posted June 10, 2010 Ok today i finally got my motor all put together. And i did a compression check, and it is about 10psi off? I am at about 140psi, and i have 20cc domes and a Aggressive dune port. I did the compression check by holding open the Throttle and having the pipes off the bike. I am about 1200 feetabove see level. Noss Website says i should be 150ish. 140 sounds about right with a port job. Quote Link to comment Share on other sites More sharing options...
Drewski Posted June 10, 2010 Report Share Posted June 10, 2010 (edited) it will go up after the break in period assuming you did the rings Edited June 10, 2010 by Drewski Quote Link to comment Share on other sites More sharing options...
firebanshee Posted June 10, 2010 Report Share Posted June 10, 2010 Ok today i finally got my motor all put together. And i did a compression check, and it is about 10psi off? I am at about 140psi, and i have 20cc domes and a Aggressive dune port. I did the compression check by holding open the Throttle and having the pipes off the bike. I am about 1200 feetabove see level. Noss Website says i should be 150ish. With your elevation and a aggressive port job it sounds like you are were you should be. Quote Link to comment Share on other sites More sharing options...
jrod Posted June 10, 2010 Author Report Share Posted June 10, 2010 Alright, Thanks Guys. Makes me feel a little better. Yes i did rings, and my elevation is about 1050. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted June 12, 2010 Report Share Posted June 12, 2010 im at sea level and a while ago when i rebuilt my motor with ported jugs, 20cc domes and .040" squish i was getting 141psi aswell. im gonna throw some 19's in. (i thought 140's was a tad low too) Quote Link to comment Share on other sites More sharing options...
KickStartMyHeart Posted June 12, 2010 Report Share Posted June 12, 2010 im at sea level and a while ago when i rebuilt my motor with ported jugs, 20cc domes and .040" squish i was getting 141psi aswell. im gonna throw some 19's in. (i thought 140's was a tad low too) .040 squish??????? Do you check it everytime u get done riding it? Im running .045 squish on a 4mill. Quote Link to comment Share on other sites More sharing options...
dirtydownunder Posted June 12, 2010 Report Share Posted June 12, 2010 nope, just when i though comp was low. havent check anything like compression or squish in over 20hrs. Quote Link to comment Share on other sites More sharing options...
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