bertmann73 Posted June 19, 2016 Report Share Posted June 19, 2016 Hello all. I am an older rider and have built many desert toys out here in vegas such as a honda v-twin dunebuggy and a 250r 3-wheeler to quad conversion. My 2 stroke knowledge is inferior to my 4 stroke knowledge but i have always managed to keep things running until i met the Banshee. I have been riding with my nephew, Manny, since he was old enough to get on a bike, and now my son has joined us. We bought the banshee new in 2005. It came with FMF and GYTR aftermarket parts from the showroom. He fell in love at first sight. I co-signed and we took it out that day. After a year the top end failed duet to infiltration through the crappy airbox setup. we bored it, got new pistons and put it back together. 6 months later it siezed up and bent a rod. We found a stock donor engine and swapped it out. at least i think its stock... Anyhoo, that engine ran for a while until we began to get misfires and only one cylinder seemed to be running. I replaced the electric carb throttle cable system with the manual ones from the donor bike just cuz i hated those things and they took up too much work space. Still same problem and then we lost the water pump gear and it overheated. we replaced it with a metal gear and got a new alluminum radiator. we put it back together but it wont run. I have gone through the carbs with a fine tooth comb and it still wont idle and the right cylinder gets hotter that hell. I am giving up at this point and gonna tear it down and rebuild it. I am hoping to gather a closet to stock rebuild list that includes a slight bore and jetting at a low cost with anything else you all may insist i do to make it a dependable ride. I am not trying to mod this thing as we dont have time for all that and the bike has plenty of power for us as is. I just want it to run so Manny can smile again when he rides (he has to ride the raptor 350 right now.........no fun) Just point me in the right direction of what to get and things to check. The bike has FMF Gold series Fattys and FMF power cores and the carbs are most likely jetted for those from Yamaha for a stock Cylinder. Please help save another banshee Quote Link to comment Share on other sites More sharing options...
JTmachining Posted June 19, 2016 Report Share Posted June 19, 2016 I'd recommend sending the complete motor to a builder. Have them take it all apart and rebuild it. I recommend Redline Racing 1 Quote Link to comment Share on other sites More sharing options...
guns4children Posted June 19, 2016 Report Share Posted June 19, 2016 Herr jugs racing would probably be the fastest turn around time if you wanted someone else to build it. If not what you should do first is get a crank with all the seals that goes along with it. Then you need pistons then you need to get the cylinders bored to match. If you were set on rebuilding it yourself I would dissemble then contact one of the site sponsors and they can set you up with everything you need. There is a complete write up on how to assemble a bottom end that walks you through step by step once you get all your parts. Quote Link to comment Share on other sites More sharing options...
bertmann73 Posted June 19, 2016 Author Report Share Posted June 19, 2016 i'm most likely just going to do the top end unless there is a need to pull apart the bottom end. no knocks and transmission/clutch is good. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted June 19, 2016 Report Share Posted June 19, 2016 Two things you should do first. Leak test the engine to see if a leak caused the failure. Then find out what jets and needle are in the carbs. Post up what you find. Banshee engine is probably the easiest engine to work on. Get a Clymers Repair Manual. Quote Link to comment Share on other sites More sharing options...
motoman011 Posted June 19, 2016 Report Share Posted June 19, 2016 Do the leak down, seems to be a common issue, and message or ask Larry, he did mine at a affordable price, awesome knowledge, definitely knows a Banshee motor, mine wasn't fine tuned, and started first kick, once a made his recommendations, it's spot on and runs period. Good guy Quote Link to comment Share on other sites More sharing options...
bertmann73 Posted June 22, 2016 Author Report Share Posted June 22, 2016 Thanks for all the input. Most likely failed rings and or head gaskets since leak down comes up so much. I do notice the compression seems low until it fires up and tries to run. Gonna get new pistons and gasket kit. Ill send the jugs out to get bored. if it still don't run right ill deal with the jetting. what reeds should i look for? Quote Link to comment Share on other sites More sharing options...
bigweav81 Posted June 22, 2016 Report Share Posted June 22, 2016 Vf4 Sent from my SM-S820L using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
tfaith08 Posted June 24, 2016 Report Share Posted June 24, 2016 Thanks for all the input. Most likely failed rings and or head gaskets since leak down comes up so much. I do notice the compression seems low until it fires up and tries to run. Gonna get new pistons and gasket kit. Ill send the jugs out to get bored. if it still don't run right ill deal with the jetting. what reeds should i look for? I don't believe you did the leak down correctly if you meant what I gathered. Quote Link to comment Share on other sites More sharing options...
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