Justintoxicated Posted November 18, 2003 Report Share Posted November 18, 2003 With 20CC domes in getting about 139 PSI...What should I do? This is after riding a tank or 2 on a fresh rebuild. It ran good but is this bad? Quote Link to comment Share on other sites More sharing options...
SDD Posted November 18, 2003 Report Share Posted November 18, 2003 Justin make sure you screw the hose as far down as it will go. Sometimes the o-ring doesn't seal that well and will change the final numbers. Quote Link to comment Share on other sites More sharing options...
MULLET~BOY Posted November 18, 2003 Report Share Posted November 18, 2003 any porting what elevation are both cylinders within 5 pounds of each other ? if so i wouldn't worry about it if its a fresh bore give it a couple more tanks to get the rings set and shit you will pick up a lil more compresion duno what kinda compresion tester your using but if it has a hose it won't be as acurate as one that dousn't have a hose but that dousn't really matter long as your cylinders have about the same compresion in each one Quote Link to comment Share on other sites More sharing options...
Justintoxicated Posted November 18, 2003 Author Report Share Posted November 18, 2003 I was just concerned because I was told it should be around 160-170 THe mods were fresh bore 2 sizes over, 20CC domes w/ NOSS cooling head and PassionRE's 12-port on the cylinders The gauge has a tube its a MityVac Compression Test kit, brand new from Alba I hand tightened it for both cylinders, Im running 1/2 110 1/2 91 pump gas Quote Link to comment Share on other sites More sharing options...
MULLET~BOY Posted November 18, 2003 Report Share Posted November 18, 2003 i don't know what they did to your motor but if they raised the exughst ports its gona drop compresion don't worry long as you got same compresion each side i'm running 15cc domes 165 each cylinder at 1,000 above sea leval just to give you a idea my compresion was within 5 pounds thats all you needto worry about being the same both sides Quote Link to comment Share on other sites More sharing options...
Justintoxicated Posted November 18, 2003 Author Report Share Posted November 18, 2003 i don't know what they did to your motor but if they raised the exughst ports its gona drop compresion don't worry long as you got same compresion each side i'm running 15cc domes 165 each cylinder at 1,000 above sea leval just to give you a idea my compresion was within 5 pounds thats all you needto worry about being the same both sides ahh yes thats probably it then. The bike flat out hauls ass, although I need bigger carbs and reeds so that I can flip myself over on take off Guess I get some smaller domes too Quote Link to comment Share on other sites More sharing options...
papa_smurf49319 Posted November 18, 2003 Report Share Posted November 18, 2003 dont rely on the compression tester, if it runs good, then dont worry about it. Only use the compression tester when youve noticed a problem Quote Link to comment Share on other sites More sharing options...
Justintoxicated Posted November 18, 2003 Author Report Share Posted November 18, 2003 dont rely on the compression tester, if it runs good, then dont worry about it. Only use the compression tester when youve noticed a problem I just wanted and initial reading after rebuild, + im trying to get it dialed in. It looks like I can get some smaller domes since im mixing 1/2 110 1/2 91 Ill check it with another tester when I get out there on T-day Quote Link to comment Share on other sites More sharing options...
. Posted November 18, 2003 Report Share Posted November 18, 2003 whats your elevation? I dont know if they raised the exhaust port or not....but that'd drop compression from whatever it is already. When I had 18cc domes at 900 feet I had 172 lbs of compression. I'd think with 20cc domes I'd have around 150 or so. Sounds like they raised your exhaust ports some. Your numbers for compression are probably about on. I'd go with some 18's and you'd still probably be safe mixing. I'd say 160, start mixing, and 165 get into straight race. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.