Yamaholic in va. Posted March 5, 2005 Report Posted March 5, 2005 Okay my buddy got his banshee bored to .060 over and now its at 98 psi. Originally with his .040 bore he got a standard 120 psi at 1200 ft, I personally checked the ring gap when we got the jugs back, was tight, had to dremal to get the 11 thousanths gap, all normal. Is my gauge wrong or is there something about boreing a jug I dont know about. This has never happened before when they have been done...... Quote
BigRed350x Posted March 6, 2005 Report Posted March 6, 2005 That little phrase... "I had to dremel" scares me. I would never take a dremel to my sleeves. Get the thing honed. For your compression issue... are you holding the throttle wide open when you kick it over? Quote
SheeMX Posted March 6, 2005 Report Posted March 6, 2005 He used a dremel to adjust the ring gap, Not bore the cylinder That little phrase... "I had to dremel" scares me. I would never take a dremel to my sleeves. Get the thing honed. For your compression issue... are you holding the throttle wide open when you kick it over? 333972[/snapback] Quote
icemanscold Posted March 6, 2005 Report Posted March 6, 2005 When I hit 90 psi its time for me to rebuild You must have a problem with yer guage. You have to hold the throttle wide open too, during testing. Quote
FORMULASPEED Posted March 6, 2005 Report Posted March 6, 2005 You have to hold the throttle wide open too, during testing. 334071[/snapback] Yep.and it also has to be warm... SheeMX Posted Yesterday, 09:29 PM He used a dremel to adjust the ring gap, Not bore the cylinder Quote
rocketboy Posted March 6, 2005 Report Posted March 6, 2005 its not uncommon for a wally world compression tester to read 20psi lower than the correct reading ,but if you used the same one then you may have a problem because they do repeat even ifthey are inaccurate. you may need to tighten your topend bolts up better or you are not seated all the way on your head Quote
cam2 Posted March 6, 2005 Report Posted March 6, 2005 did you guys do the break-in procedure (heat up, cool down, re-torque, 2 to 3 times, run a tank of gas throught it) before you checked the compression? most engine builders recommend this so that things seal properly and your rings seat well. as others have stated the engine needs to be warm and you have hold the throttle wide open, plus you will have to kick your tail to get a good reading. Quote
Yamaholic in va. Posted March 6, 2005 Author Report Posted March 6, 2005 did you guys do the break-in procedure (heat up, cool down, re-torque, 2 to 3 times, run a tank of gas throught it) before you checked the compression? most engine builders recommend this so that things seal properly and your rings seat well. as others have stated the engine needs to be warm and you have hold the throttle wide open, plus you will have to kick your tail to get a good reading. 334228[/snapback] Yes, did the 5,10,15 break in with cool downs between. Havent rechecked the head bolts yet. Also I have always checked the compression cold. The bike runs great, so that is not an issue. The gauge is showing the same reading 98 on both sides... Quote
Wallrat Posted March 6, 2005 Report Posted March 6, 2005 Um...not to sound to obvious but you did buy new pistons right? Assuming you did, did you send the pistons out with the cyls so that they would bore them to the size of the pistons? How were the reeds? Maybe during the teardown you got some gunk in there...although I doubt it since its both sides. Quote
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