Heylookitsdylan Posted April 21, 2012 Report Share Posted April 21, 2012 I recently started having a problem with my banshee cutting out on the right cylinder at mid to upper RPM range. It first happened while i was out riding with a friend, we rode about 60ish miles that night on dirt roads. I went to make a pull from 3rd, through 6th, and at the top of 6th it fell on its face, much like a fouled plug, The cylinder went silent/dead. I rode for a minute or two before changing plugs, And nothing changed. So i limped her home, Rode great on the low to mid end.. My first thought was maybe a spark issue? Swapped wires left and right, nothing changed. It was suggested maybe reed valves getting weak? Wouldnt that be more of a low end problem? They feel tight and have no damage or cracks. I pulled the carb (28mm Keihin PWK), seemed to be normal. Next step I think i should do a compression test on both sides. If it matters: '98 Banshee Stock bore, never bored honed or ringed. (Starts on first kick after sitting for weeks) Keihin 28mm PWK's 3/8'' Pro-circuit pipes K&N 2-into-1 Filter with no box Right now Im running out of ideas. ANY help is greatly appreciated! Quote Link to comment Share on other sites More sharing options...
Wildcardracing Posted April 21, 2012 Report Share Posted April 21, 2012 If you have access to a flywheel puller, pull the flywheel and shake it see if it rattles. Broken flywheel magnets can/will cause misfiring at certain rpms Quote Link to comment Share on other sites More sharing options...
mhoksch Posted April 21, 2012 Report Share Posted April 21, 2012 I just had a similar problem. Mine was fixed by adjusting float levels and I was a bit lean so I went up on my main jet. Runs a lot better now but still not perfect Quote Link to comment Share on other sites More sharing options...
Sandking Posted April 21, 2012 Report Share Posted April 21, 2012 Put some new plug boots on it..... Quote Link to comment Share on other sites More sharing options...
mhoksch Posted April 21, 2012 Report Share Posted April 21, 2012 Put some new plug boots on it..... He said he swapped wires and it still did it which would rule out boots right? Quote Link to comment Share on other sites More sharing options...
Heylookitsdylan Posted April 21, 2012 Author Report Share Posted April 21, 2012 If you have access to a flywheel puller, pull the flywheel and shake it see if it rattles. Broken flywheel magnets can/will cause misfiring at certain rpms I will check that out when i tear into it! I just had a similar problem. Mine was fixed by adjusting float levels and I was a bit lean so I went up on my main jet. Runs a lot better now but still not perfect I thought about this, But it just started out of nowhere? Ill have to check this as well! Put some new plug boots on it..... Plug boots look great, still soft and pliable and not cracked. Thanks for the help thus far guys! Quote Link to comment Share on other sites More sharing options...
BWells3 Posted April 29, 2012 Report Share Posted April 29, 2012 I had a similar problem when i finished my serval build. It ran good on the bottom but fell on its face just as it was getting on the pipe. I chased it for a while checking boots, wires, coil, gap clearance, fuel / carb issues, jetting, everything. I jetted from 160 down (28pwk's). I got to 125's and it was still rich. I knew this couldn't be right. I thought that it was only running on one cylinder bc one pipe was much warmer than the other. I dont have the money for shearers yet so i threw on a set of t5,'s with a spark arrestor / hush kit that i had laying around. I knew they would be restrictive but this was rediculous. I was stumped and began to think something had plugged up the stingers. I took them apart but they were clean. When I was putting them back on I decided to look at the spark arrestor. The screen was completely plugged. I have never really ran a spark arrestor before so it hadn't even crossed my mind. I pulled the screen out and cleaned it real good. Problem solved. I know its not likely that the exhaust plugged up while you were riding but thought that I would throw it out there. Sorry for writing a book but I wish I could have found a post like this so I hope its helpful to someone. Bottom line, as with everything, start basic and work your way through. I would start at the plugs and work my way through the electrical system. I know you switch plug wires which likely eliminates them but I would recommend you call Jeff at fast and get some of the taylor wires just to be sure. Cheap upgrade and so far seem to be a solid product with a really secure fit. Jeff told me that he ran them on his drag bike for a long time until he upgraded his coil. It also could be the coil breaking down aon the top end or when it gets hot. Anyway I hope you get it all worked out... Quote Link to comment Share on other sites More sharing options...
Jackl Posted April 30, 2012 Report Share Posted April 30, 2012 my banshee did this and unfortunetly it ran for the day then blew the rings on the right piston. worn bore waited to long to do topend oh well all new stuff and running like a champ now hope yours is an easier fix but I would check compression. Quote Link to comment Share on other sites More sharing options...
Heylookitsdylan Posted May 4, 2012 Author Report Share Posted May 4, 2012 my banshee did this and unfortunetly it ran for the day then blew the rings on the right piston. worn bore waited to long to do topend oh well all new stuff and running like a champ now hope yours is an easier fix but I would check compression. Turns out the compression was low. Shes now freshened up and ready to rock, Thankfully it was caught soon enough! Thanks for all the help guys! Quote Link to comment Share on other sites More sharing options...
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