jmkapala Posted January 24, 2007 Report Posted January 24, 2007 i have a cool head w/ 18cc domes....i just did a compression test w/ about 151psi in both jugs....i live in a suburb of detroit at about 650 ft above sea level.... is this compression ok? Quote
okbeast Posted January 24, 2007 Report Posted January 24, 2007 According to the chart on this site http://www.nossmachine.com/banshee_heads.htm you should be around 170-180 psi with that size domes and that elevation. Did you test it when the bike was warm and hold the throttle wide open and kick till you couldn't kick anymore? Quote
jmkapala Posted January 24, 2007 Author Report Posted January 24, 2007 (edited) According to the chart on this site http://www.nossmachine.com/banshee_heads.htm you should be around 170-180 psi with that size domes and that elevation. Did you test it when the bike was warm and hold the throttle wide open and kick till you couldn't kick anymore? No, its 26 degrees up here. wasnt sure exactly how to test it on a banshee.....hooked up the tester and kicked untill it quit going up (the compression tester).... also its a 20 over bore....sorry Edited January 24, 2007 by jmkapala Quote
sheefreak Posted January 24, 2007 Report Posted January 24, 2007 That's pretty low for 18cc domes. You might warm it up as mentioned and give it a shot to see if it is a drastic difference, but I doubt it. You may be just looking at rings and a hone both cyls, or new topend and bore job depending on the wear. Quote
dajogejr Posted January 24, 2007 Report Posted January 24, 2007 i have a cool head w/ 18cc domes....i just did a compression test w/ about 151psi in both jugs....i live in a suburb of detroit at about 650 ft above sea level.... is this compression ok? It's a little low...but, it should start and run. Those PSI reading on the NOSS site are appoxamate, not bible. That being said...it's a little low. Did you hold the throttle wide open the whole time you were kicking? Jim, since I know you're a "stang fanatic, I'm sure you used a good quality compression tester, so we can rule that out. I'm available tomorrow after 5:30 PM if you're gonna be home... you got my number. I'd be happy to stop by and take a look. I'm really curious to see what kind of condition those carbs are in. Did you ever find out what jets on in them?? Quote
I hate WYO Posted January 24, 2007 Report Posted January 24, 2007 is it ported that will bring your comp down too Quote
bigboybanshee Posted January 24, 2007 Report Posted January 24, 2007 is it ported that will bring your comp down too That's the first thing I thought.... Quote
jmkapala Posted January 25, 2007 Author Report Posted January 25, 2007 unfortunately, i know nothing about this bike i got it as is.......as stated in "stator help," i think i seriously got BS'ed Quote
dlnoss Posted January 25, 2007 Report Posted January 25, 2007 Also, if the compression tester doesn't thread into the spark plug hole as far as the spark plug, it will give a false low reading. Quote
Bigkahun74 Posted January 25, 2007 Report Posted January 25, 2007 that seems way to low compression for 18cc domes ported or not. i got a drag/dune port on my shee with a pro design cool head running 19cc domes and my compression is 175psi and i'm in northwest indiana (1 hour southeast of gary,in) and i have a craftsman compression tester Quote
Animalman294 Posted January 25, 2007 Report Posted January 25, 2007 Unless there is really something wrong with the crank seal, reeds, or the rings............. Quote
jmkapala Posted January 25, 2007 Author Report Posted January 25, 2007 I'd like to thanks everyone for they're help..... I just re-checked the compression and this time i did it on a "wide open throttle" about 173 in both jugs......also, the motor was not warm as i cant get her started..... Quote
dajogejr Posted January 26, 2007 Report Posted January 26, 2007 That sounds more like it... If you goose it with some starting fluid, will it attempt to start? Quote
jmkapala Posted January 26, 2007 Author Report Posted January 26, 2007 That sounds more like it... If you goose it with some starting fluid, will it attempt to start? nope..... Quote
dajogejr Posted January 26, 2007 Report Posted January 26, 2007 So here's where this one stands. I take the carbs apart, these are stock carbs on a piped shee...by the way. Anyone want to guess what size pilots he has? 45. Yes, you read that right, 45's. And the guy he bought it off of told him it was jetted for 70 degree weather... :shoothead: And, the left side carb threads are so stripped/worn, the brand new throttle caps he got literally fall onto the top of the carb, as if there were NO threads there at all. So...he has a spare left carb. I'm going to drill and tap that for the idle screw, and sent him off to the store to get jets. He removed the airbox, and is going to pods. I sent him to get 27.5 pilots, 340 to 370 mains (it was a balmy 10 degrees in his garage yesterday) and a box of BR8ES plugs. That's where it stands right now... Although he said it wouldn't start before, I think 45 pilots are a big part of the problem. So...gonna start there. With 175PSi in each jug, that should be fine....we'll get it sorted!! Quote
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