bink98xcab Posted February 28, 2008 Report Share Posted February 28, 2008 (edited) ok heres tha problem i went for a ride today and tha shee died and backfired so i guessed i probly losat one cylinder and yes thats what happened i had 150 and 147psi and i was running 91 octane w octane booster, and blew a whole right through the center of one piston , but the other looks fine, is this to much compression for 91? i have 21cc domes at sea level , the topend has less than 5 hrs on it and has 64.5 pro lites. should i get 22cc's and replace the one piston? walls of cylinder feel fine . no scroring . any help would be egreat http://i272.photobucket.com/albums/jj170/b...pg?t=1204236984 http://i272.photobucket.com/albums/jj170/b...pg?t=1204237038 Edited February 28, 2008 by bink98xcab Quote Link to comment Share on other sites More sharing options...
shee rips Posted February 28, 2008 Report Share Posted February 28, 2008 looks lean to me. plugged main jet is my guess Quote Link to comment Share on other sites More sharing options...
scjandllj Posted February 28, 2008 Report Share Posted February 28, 2008 you didnt blow a hole you burned a hole.... too lean man Quote Link to comment Share on other sites More sharing options...
bink98xcab Posted February 28, 2008 Author Report Share Posted February 28, 2008 so you dont think it was to much compression? the plug was brown yesterday and the plug was tight and i just had the carbs apart last weak and they wasnt any trash. im running k&n pods 340 mains fmf pipes noss head vforce3's , one of my buddies did this but his plug was about to pop out when the top went, so i knew his leaned out. Quote Link to comment Share on other sites More sharing options...
dlnoss Posted February 29, 2008 Report Share Posted February 29, 2008 I can't see the pictures very well but unless your timing is advanced a lot, you shouldn't detonate in Oklahoma with 21cc domes and 91 octane. I would run 93 octane if you can get it. -David Quote Link to comment Share on other sites More sharing options...
bink98xcab Posted February 29, 2008 Author Report Share Posted February 29, 2008 well my timing is at 4degrees, and like i say one piston looks fine and i have ran a few tank fulls through it with no prob. all i can find is 91 ,i been using 91 vpower from shell caus its about good as i can find. Quote Link to comment Share on other sites More sharing options...
jmd0346 Posted February 29, 2008 Report Share Posted February 29, 2008 ok heres tha problem i went for a ride today and tha shee died and backfired so i guessed i probly losat one cylinder and yes thats what happened i had 150 and 147psi and i was running 91 octane w octane booster, and blew a whole right through the center of one piston , but the other looks fine, is this to much compression for 91? i have 21cc domes at sea level , the topend has less than 5 hrs on it and has 64.5 pro lites. should i get 22cc's and replace the one piston? walls of cylinder feel fine . no scroring . any help would be egreat http://i272.photobucket.com/albums/jj170/b...pg?t=1204236984 http://i272.photobucket.com/albums/jj170/b...pg?t=1204237038 IMO 91 is too low for 150psi. Octane booster isnt gonna help either. Its a gimmick. It raises actual octane by like half a point at most. The only real octane booster is Torco. However, looks like you really leaned out on that jug for some reason. If it was just octane both pistons would be affected. It has to really go seriously lean to melt a hole in a piston. You should have been able to feel it. It should have gave signs of leaning out. Quote Link to comment Share on other sites More sharing options...
bink98xcab Posted February 29, 2008 Author Report Share Posted February 29, 2008 (edited) i gues il tear down the carb on that side after work tomorow to see if thats the prob , caus right now im stumped, and thanks for the help :: the only sign of bein lean was right before it died when i gave it WOT and it wouldnt pulled hardley past 3/4 throttle Edited February 29, 2008 by bink98xcab Quote Link to comment Share on other sites More sharing options...
jmd0346 Posted February 29, 2008 Report Share Posted February 29, 2008 i gues il tear down the carb on that side after work tomorow to see if thats the prob , caus right now im stumped, and thanks for the help :: the only sign of bein lean was right before it died when i gave it WOT and it wouldnt pulled hardley past 3/4 throttle Yep. Did it sound hollow and boggy? Something happened on that carb and it completly lost fuel. Quote Link to comment Share on other sites More sharing options...
bink98xcab Posted February 29, 2008 Author Report Share Posted February 29, 2008 well it only had that "holow , boggy " sound after i started it after it died, and then i knew what was up, but like i sade , right before it died it had that no rev , lean feeling, but BOOM it was to late and hadnt ever gave previous probs Quote Link to comment Share on other sites More sharing options...
jmd0346 Posted February 29, 2008 Report Share Posted February 29, 2008 well it only had that "holow , boggy " sound after i started it after it died, and then i knew what was up, but like i sade , right before it died it had that no rev , lean feeling, but BOOM it was to late and hadnt ever gave previous probs I messed up my float heights last time I changes jets on my OKO's. Caused my bowls to run out. I caught it and fixed it before it did any damage that I know of. Might wanna check that. Quote Link to comment Share on other sites More sharing options...
BellicoseBanshee Posted February 29, 2008 Report Share Posted February 29, 2008 so you dont think it was to much compression? the plug was brown yesterday and the plug was tight and i just had the carbs apart last weak and they wasnt any trash. im running k&n pods 340 mains fmf pipes noss head vforce3's , one of my buddies did this but his plug was about to pop out when the top went, so i knew his leaned out. Detonation can cause the plug to back out... Quote Link to comment Share on other sites More sharing options...
bink98xcab Posted February 29, 2008 Author Report Share Posted February 29, 2008 Detonation can cause the plug to back out... well im leaning toward a lean condition, and both plugs were still tight, thats sunthn i always check b4 i ride Quote Link to comment Share on other sites More sharing options...
sheefreak Posted February 29, 2008 Report Share Posted February 29, 2008 I would make sure I did a pressure test on the motor when you get it back together. Had you checked the plugs at all after the rebuild and running it a bit? Quote Link to comment Share on other sites More sharing options...
bink98xcab Posted March 3, 2008 Author Report Share Posted March 3, 2008 I would make sure I did a pressure test on the motor when you get it back together. Had you checked the plugs at all after the rebuild and running it a bit? oh yea i have checked the plugs after each ride , because i have been adding a few mods one a time , and i havent really had more than a couple rides each before the next mod. i planeed on checked the pressure after i get it back together. any one know where a good place to just get the rings? (pn# 2539cd) i ordered a piston off ebay but tha stupid thing dont come w rings!! i didnt realize till i won the auction. Quote Link to comment Share on other sites More sharing options...
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