Pincushion Posted August 4, 2008 Report Posted August 4, 2008 I just picked up a 03' with an estimated 20 hours. I believe the guy as the frame and everything looks great, but I'd like to get a compression reading for the helluvit. My 06 YZ250 pulled a 215lb reading after a fresh top end, which is great compression for a 250 and shows my gauge is in the ballpark. With that in mind what should I expect from each cylinder? Stock motor, stock carbs, FMF fatty's and K&N's (no airbox) are the only mods. I'm at 300ft ASL. Lastly, should the reading be taken on a motor at operating temp or stone cold? My YZ blew a 215 at operating temp and lower when cold. Quote
mdhc500 Posted August 4, 2008 Report Posted August 4, 2008 (edited) I just picked up a 03' with an estimated 20 hours. I believe the guy as the frame and everything looks great, but I'd like to get a compression reading for the helluvit. My 06 YZ250 pulled a 215lb reading after a fresh top end, which is great compression for a 250 and shows my gauge is in the ballpark. With that in mind what should I expect from each cylinder? Stock motor, stock carbs, FMF fatty's and K&N's (no airbox) are the only mods. I'm at 300ft ASL. Lastly, should the reading be taken on a motor at operating temp or stone cold? My YZ blew a 215 at operating temp and lower when cold. #'s from NOSS Machine... .........Sea Level..1000'.2000'.3000'..4000'..5000' 18cc.........197.....178...171...170.....165.....145 19cc.........183.....167...160...158.....152.....137 20cc.........169.....156...149...146.....140.....129 21cc.........156.....145...138...134.....128.....121 stock........130.....125...118...112.....106.....100 I would say between 120 and 130 psi give or take and look for them to be betwwen 1-3 psi difference per side. Check it cold, with WOT and kick it until you get the highest #... Good luck Edited August 4, 2008 by mdhc500 Quote
Pincushion Posted August 4, 2008 Author Report Posted August 4, 2008 Good info. Thanks a bunch! Quote
Pincushion Posted August 6, 2008 Author Report Posted August 6, 2008 (edited) It blew a 125 and 120 respectively. I was able to repeat those numbers twice. Is a 5# fluctuation something to be concerned about? I took it out yesterday and it runs and sounds great. I hadn't ridden a Banshee since the mid 90's and I forgot how much fun they are. Good times.... Edited August 6, 2008 by Pincushion Quote
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.