jrod Posted July 1, 2008 Report Posted July 1, 2008 Ok i just picked up a bike with alot of good parts a few days back, starts darn near everytime. But was not running right. So i pulled the motor out and pulled it down. Here is what i have found. this could be the reason for low compression? And i have a few more ? The next few pictures are of the cylinders. The guy i got it from said it had been ported and bored. Can any one tell me from the pics if this is true, and are these stock reed valves? these pistons look pretty new huh?\ and my personal opinon is this is a 40 over bore and do most of you guys garages look like these full of quads! Quote
magz Posted July 1, 2008 Report Posted July 1, 2008 reed cages look stock with some carbon fiber reeds... head looks like 1 of my buddys after his wrist pin bearings broke and got ontop. didnt really hurt preformance cause it didnt scar the cyclender wall. but you should probably pickup a cool head with some 20-21cc domes anyways. and if the pistons not beat like the top of that head it was from a re-build blow up. Quote
jrod Posted July 1, 2008 Author Report Posted July 1, 2008 Pistons look brand new. Look to me like who ever had the bike before, had something go wrong and said fuck it and put the POS head back on. Quote
sheerider1026 Posted July 1, 2008 Report Posted July 1, 2008 yea that is definately a past blow up and rebuild.. if the head looks that bad then the piston and cylinder would also.. a lot of pwople reuse the head when they look like that, not a big deal in my opinion, looks like someone did a cleanup port on it.. did you do a compression test before you took it apart?? could be just a carb issue making it not run right.. or something else with the tuning.. just my thoughts on it.. if the compression was good i would never take one apart, first thing would be to try a set of new plugs, then if no change i would take the carbs off and clean them and check everything.. a clogged pilot will make one run like shit.. i have also ran across shees that ran like shit and someone had the carb slides in backwards.. not trying to be negative on ya bro.. just my opinion.. would be a good time to re-ring it and put a noss head on there.. Quote
Wildcardracing Posted July 1, 2008 Report Posted July 1, 2008 Those are boyesen pro-series reeds, looks like a very mild cleanup on the intake, exhaust and lower transfer ports, would have to have some roof to deck measurements to tell you if any durations have been changed. I agree with sheerider, there may have been no need to tear it down. Quote
jrod Posted July 1, 2008 Author Report Posted July 1, 2008 Those are boyesen pro-series reeds, looks like a very mild cleanup on the intake, exhaust and lower transfer ports, would have to have some roof to deck measurements to tell you if any durations have been changed. I agree with sheerider, there may have been no need to tear it down. When i got the Bike there was no AirFilter and he said it had been sitting for months. So that scared me, and i had never actually torn one down before. And i wanted to see what all was done. But if i had to guess i would say carb issues as well, he installed a twist throttle and i bet that is the issue. I am putting my A&S motor on my other bike and am going to use those carbs on this bike to make two good running bikes. Quote
magz Posted July 1, 2008 Report Posted July 1, 2008 When i got the Bike there was no AirFilter and he said it had been sitting for months. So that scared me, and i had never actually torn one down before. And i wanted to see what all was done. But if i had to guess i would say carb issues as well, he installed a twist throttle and i bet that is the issue. I am putting my A&S motor on my other bike and am going to use those carbs on this bike to make two good running bikes. probably need to sync the carbs up. i had my caps off a couple times and mine were way out of sync. ran and idled alot better after i synced mine. Quote
jrod Posted July 1, 2008 Author Report Posted July 1, 2008 how do you sync them? I am real new to banshee. Quote
okbeast Posted July 1, 2008 Report Posted July 1, 2008 Use the adjusters on the top to make sure they're opening at the same time and approximately the same amount. you can do it by eye, or feel, or get one of Jeffs sync tools Quote
FireHead Posted July 1, 2008 Report Posted July 1, 2008 That engine has most likely been rebuilt since that dome damage occurred. There would be other stuff loose and scarred including the top of the piston if that happened with the current parts in the engine. :thumbsup: Quote
Bansheeb0y5505 Posted July 1, 2008 Report Posted July 1, 2008 umm, jrod. You have your front end set up completely wrong. The upper arms are upside down and it looks way to close to the groungd Quote
jrod Posted July 1, 2008 Author Report Posted July 1, 2008 umm, jrod. You have your front end set up completely wrong. The upper arms are upside down and it looks way to close to the groungd I broke a left side balljoint. But i have the a-arms on wrong. Ha figures. Quote
KlotzBanshee Posted July 1, 2008 Report Posted July 1, 2008 The next few pictures are of the cylinders. The guy i got it from said it had been ported and bored. Can any one tell me from the pics if this is true, and are these stock reed valves? it looks like they have been clean-up ported and probably bored, the reed valves are stock but the reeds are not, idk what those are. Oh, and the reed stops are missing also. these pistons look pretty new huh?\ The pistons don't look too bad, little worn. Those ARE Wiseco rings in them right? The bottom rings look thicker to me for some reason??? Wiscecos are usually the same thickness top and bottom, but stock rings are not. :shrug: and WOW Jrod...a little soap and water goes a long way. It hurts my eyes to see dirt and sand getting into your crank case like that. Plus the job is so much nicer when everything is somewhat clean, just my $.02 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.