98_shee Posted February 25, 2008 Report Posted February 25, 2008 Need help I've looked everywhere and cant find any thing on this, here's what it is doing, when the bike is at an idle or about 1/8 throttle it only runs on the right side, and it backfires on the left side when you open the throttle up and let off, here's what we have tryed, synced the carbs, tryed whole different set of carbs, different coil, different stator,different reeds, adjusted needles up and down, changed all jets, and air screws, everything is spotless in the carbs, we also checked all the wire connections, what is the easiest way to do a pressure check? Its not the bike in the sig its a friends bike, Mods are, 300 main, 27.5 pilot, air screws 1.5 out, tors removed, k&n with airbox and lid removed, fmf fattys thats about it, he purchased the bike blown up and rebuilt it and it has never ran right, thanks in advance for the help!! :: Quote
tripledsracing Posted February 25, 2008 Report Posted February 25, 2008 Need help I've looked everywhere and cant find any thing on this, here's what it is doing, when the bike is at an idle or about 1/8 throttle it only runs on the right side, and it backfires on the left side when you open the throttle up and let off, here's what we have tryed, synced the carbs, tryed whole different set of carbs, different coil, different stator,different reeds, adjusted needles up and down, changed all jets, and air screws, everything is spotless in the carbs, we also checked all the wire connections, what is the easiest way to do a pressure check? Its not the bike in the sig its a friends bike, Mods are, 300 main, 27.5 pilot, air screws 1.5 out, tors removed, k&n with airbox and lid removed, fmf fattys thats about it, he purchased the bike blown up and rebuilt it and it has never ran right, thanks in advance for the help!! :: my bike done the same thing..i changed everything from carbs,intake gaskets,coil,plug wires,stator..it was an air leak..also the crank bearing was bad...did he replace the crank bearings and seals on the bottom end when he fixed it?if not there is the prob..its always best to tear it down completely and go over eveything.. Quote
98_shee Posted February 25, 2008 Author Report Posted February 25, 2008 The guy he bought it from try to port it himself and got into one of the water jackets then the dumb ass put that radiator stop leak in it and kept pouring it in until it locked up so the crank was shot and cylinders were shot, the the guy that bought it just built a cheeta bike so he had all the extra parts to build it, so he went through the whole bottom end and cleaned all the junk out of it and put his old crank in it with new seals, we took the flywheel off and the stator off and looked at the seal from the outside of the cased and it looked good from what we could tell Quote
MSBansheeDrags Posted February 25, 2008 Report Posted February 25, 2008 my bike done the same thing..i changed everything from carbs,intake gaskets,coil,plug wires,stator..it was an air leak..also the crank bearing was bad...did he replace the crank bearings and seals on the bottom end when he fixed it?if not there is the prob..its always best to tear it down completely and go over eveything.. mine is doing the same thing basically...except the left side is putting out smoke or steam and run a little...i think it has an air/water leak...i ordered a pressure tester off of Ebay but the plugs were stock size and i needed them for a DM cylinder... try these links: http://cgi.ebay.com/ebaymotors/ws/eBayISAP...609343&rd=1 http://www.widgetco.com/rubber-stoppers the first one is for the test kit and the other is for the various size stoppers you may need...i ordered 42mm for the DM motor, i think... dbr :biggrin: Quote
tripledsracing Posted February 25, 2008 Report Posted February 25, 2008 mine is doing the same thing basically...except the left side is putting out smoke or steam and run a little...i think it has an air/water leak...i ordered a pressure tester off of Ebay but the plugs were stock size and i needed them for a DM cylinder... try these links: http://cgi.ebay.com/ebaymotors/ws/eBayISAP...609343&rd=1 http://www.widgetco.com/rubber-stoppers the first one is for the test kit and the other is for the various size stoppers you may need...i ordered 42mm for the DM motor, i think... dbr :biggrin: on some motors they will smoke on one side more than the other..that could be your carbs out of synch..because the left side of your cylinders cant suck tranny oil on that side..id say get the air leak tester check to make sure thats not the problem..and yes the dm cylinders exhaust flange is bigger i was thinking it was 40mm but not for sure on that... Quote
98_shee Posted February 25, 2008 Author Report Posted February 25, 2008 I'll tell him to get a pressure tester and check it for leaks. Thanks for the help and the link Quote
akita8 Posted February 27, 2008 Report Posted February 27, 2008 My son had a problem with his banshee last weekend. It just died on him at the dunes so we towed it back and he got it running at camp but it would backfire. He thought he blew a cylinder so he tore into it and did'nt find anything wrong mechanically. I started shooting wires and found one of the wires coming from the CDI had melted to the pipe. Pulled it off the pipe and it ran fine. Quote
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