thek5king Posted July 2, 2011 Report Posted July 2, 2011 Ok so heres the story...Ive never owned a Banshee, always wanted one when I stumbled on deal..so I bought this 98 Banshee about a week ago..I knew it had some issues but I got a good deal on it so I didnt care....I took it out and around the yard a little bit and it was rippin' so I figured I would ride it a little bit and get it cleaned out... So I took off down the road and after about 2 miles of running sweet, it starts to bog down and dies....Siezed up like a mofo.....So after retrieving it back to the shop, I start disassembly and immediatly notice both carb boots are cracked and have been repaired with rubber cement or something and repainted over....So I am now realizing that she leaned out on me and I prepare for the carnage...I pull the head and I am greeted by piston domes that look like someone took a chisel to them but the cylinders look decent other than some debris build up....I only honed them for about 20 seconds and they were like new...So I had a Std. bore Namura top end kit over-nighted to me along with some new carb boots. The case was clean and everything seemed tight so I forged on the next evening and put her back together..The reeds looked good and they apppeared to be carbon fiber of some brand..I also put two new NGK plugs in it..After reassembly it didnt seem to want to start so I pull started it, and after a few feet it fired right up, but it had perpetual case of back-firing so I decided after 10 mins. to let it rest for the night..The next day I tow started it again and it was still backfiring but it seemed to get a little better, however it would not idle to save its life, after getting it restarted in the woods it seemed to only be running on one cylinder and it was really boggy. I decided it must be starving for fuel, so I removed the tank only to find that were a black and a yellow wire worn through and they looked like they had been shorting out on the head...So I taped them up and moved on figuring that it was my real problem....I took the carbs apart everything looked spotless, so I blew everthing out and put them back together...Upon removal of the petcock I am greeted by sand and other various debris...So I cleaned everthing out and put it all back together with new gas line....I figured I was ready to rock now...But again I had to tow start it, and it runs on the right cylinder 100% of the time but the left only fires about 30% of the time.....I am now at the end of my knowledge...I am no expert on these machines....It ran beautiful before, even with roached pistons.....This is a list of what I know is in it..... I presume it was rejetted when the pipes were installed as they were put on about 5 years ago and it ran awesome the whole time K & N Air Filter w/ Pro-Flow adapter and Outerwears Pre-Filter FMF Boost Bottle FMF Gold Series Fatty Pipes w/ FMF Powercore 2 Carbon Fiber Reeds Completely rebuilt Top End Fuel system cleaned top to bottom New NGK Plugs As of right now I only have about $1250 invested I really want to ride her today so any help would be greatly appreciated.. I have read some threads on here about back firing and have everything from people saying to ditch the NGKs and get Iridium plugs to having water in the gas....I feel its a spark problem but I cant be sure....I really dont know where to look next...Please Help Thanks Trent Quote
coryv4 Posted July 2, 2011 Report Posted July 2, 2011 Ok so heres the story...Ive never owned a Banshee, always wanted one when I stumbled on deal..so I bought this 98 Banshee about a week ago..I knew it had some issues but I got a good deal on it so I didnt care....I took it out and around the yard a little bit and it was rippin' so I figured I would ride it a little bit and get it cleaned out... So I took off down the road and after about 2 miles of running sweet, it starts to bog down and dies....Siezed up like a mofo.....So after retrieving it back to the shop, I start disassembly and immediatly notice both carb boots are cracked and have been repaired with rubber cement or something and repainted over....So I am now realizing that she leaned out on me and I prepare for the carnage...I pull the head and I am greeted by piston domes that look like someone took a chisel to them but the cylinders look decent other than some debris build up....I only honed them for about 20 seconds and they were like new...So I had a Std. bore Namura top end kit over-nighted to me along with some new carb boots. The case was clean and everything seemed tight so I forged on the next evening and put her back together..The reeds looked good and they apppeared to be carbon fiber of some brand..I also put two new NGK plugs in it..After reassembly it didnt seem to want to start so I pull started it, and after a few feet it fired right up, but it had perpetual case of back-firing so I decided after 10 mins. to let it rest for the night..The next day I tow started it again and it was still backfiring but it seemed to get a little better, however it would not idle to save its life, after getting it restarted in the woods it seemed to only be running on one cylinder and it was really boggy. I decided it must be starving for fuel, so I removed the tank only to find that were a black and a yellow wire worn through and they looked like they had been shorting out on the head...So I taped them up and moved on figuring that it was my real problem....I took the carbs apart everything looked spotless, so I blew everthing out and put them back together...Upon removal of the petcock I am greeted by sand and other various debris...So I cleaned everthing out and put it all back together with new gas line....I figured I was ready to rock now...But again I had to tow start it, and it runs on the right cylinder 100% of the time but the left only fires about 30% of the time.....I am now at the end of my knowledge...I am no expert on these machines....It ran beautiful before, even with roached pistons.....This is a list of what I know is in it..... I presume it was rejetted when the pipes were installed as they were put on about 5 years ago and it ran awesome the whole time K & N Air Filter w/ Pro-Flow adapter and Outerwears Pre-Filter FMF Boost Bottle FMF Gold Series Fatty Pipes w/ FMF Powercore 2 Carbon Fiber Reeds Completely rebuilt Top End Fuel system cleaned top to bottom New NGK Plugs As of right now I only have about $1250 invested I really want to ride her today so any help would be greatly appreciated.. I have read some threads on here about back firing and have everything from people saying to ditch the NGKs and get Iridium plugs to having water in the gas....I feel its a spark problem but I cant be sure....I really dont know where to look next...Please Help Thanks Trent bad crank seal? Quote
Larry's Shee Posted July 2, 2011 Report Posted July 2, 2011 check that the "lugs" on flywheel are clean/rust free. Set pick-up gap at .018, check at both lugs. Make sure flywheel is tight. Try swapping plug wires to see if it switches sides. Might want to do leak-down test. Quote
SuprSlow50 Posted July 2, 2011 Report Posted July 2, 2011 x3 on the leakdown test, it is cheap, easy, and a good starting point so you don't fry the new pistons from running lean again. Both my Banshees leaked at the reed gaskets and the intakes, one has stock intakes with crossover and the other has UPP intakes and both of them leaked pretty bad. There is a thread on here on how to make one, it's very easy and adds peace of mind. Out of curosity what was the jetting in the carbs? Keep us posted. Quote
fastquad02blaster Posted July 3, 2011 Report Posted July 3, 2011 Get rid of the boost bottle or your boots will crack again. Im thinking somehow electrical problem. Check your plug boots and make sure that you have good connections there. Quote
thek5king Posted July 4, 2011 Author Report Posted July 4, 2011 Ok, Well here is a bit of an update.... After doing some reading and looking around on this site I kept reading different shit about a choke tube....and Im thinking wtf is the choke tube? And as I soon realized it was MIA SO after I put on in it seems to be running way better I rode it for about 10 min. last night and it didnt backfire once....but it still wont idle for shit...I have to give it just a hair of gas and it will fire, but after its running you have to feather the throttle or it dies....Ive about removing the TORS which I presume is the frankenstein looking thing on top of the carbs....How hard is that to drill the idle screws and stuff? What do I do with the throttle cables? Do have to buy a kit to get that junk off of there? Also I have the stock crossover tube, should I just replace the boost bottle with that? I really dont know shit about carbs so I have no clue about jets and what not..but it definitely running sweet right now.....Thanks Trent Quote
Larry's Shee Posted July 4, 2011 Report Posted July 4, 2011 http://bansheehq.com/forums/index.php?showtopic=135591 Good DYI. Work slow and carefull, carb bodies are soft and you can jack them. Be sure to only use PROPER sized tap drill size, not whatever you think is close. Use lots of cutting oil and turn tap 1/3 turn then back up to remove chips, cut little more , back tap up, repete. Quote
Jereme6655 Posted July 5, 2011 Report Posted July 5, 2011 larry's shee is right....that is a good write up. its not hard....it'll take you a probably about a half hour to do both carbs. Yes the frankenstien things on the carbs are part of the TORS.....and yes you need to get a kit to remove them. or you can buy everything seperate......but why do that....its cheaper to get the kit through our site sponsors here. Have you tried adjusting your idle? on a bike that still has the TORS boxes on the carbs there is a knob on the top of each that has a slotted spot for a flat headed screwdriver. turning both of those equal amounts starting with 1/2 turns will increase your idle. Quote
thek5king Posted July 9, 2011 Author Report Posted July 9, 2011 Ok well...It ran sweet for an hour or so and then it started doing the same thing...popping and spitting on the left cylinder...The right side runs flawlessly...So I decided to tear it all apart and see whats going on.....And come to find out it had 240 mains and 25 pilots.....which according to what Ive read is nowhere near enough...So I took a trip to the Yamaha dealer hoping they would have 27.5 pilots and 290 mains...They the pilots but the biggest set of mains they had was 260...so I put those in hoping for the best....The needles are on the middle clip and I turn the mix screws out 1.5..... I havent started it yet but I know that wont solve the misfire problem.....Could this be an electrical problem? I am really starting to doubt that it is a fuel problem....I think it keeps losing spark on one side for some reason....Any thoughts on why the problem would go away and then come back out of nowhere? Quote
Jereme6655 Posted July 11, 2011 Report Posted July 11, 2011 actually your "backfiring" may infact be a lean backfire.....the FMF fatties that your talking about really need to be using a 27.5 pilot..... mine did what your describing when it was running on stock pilots from the previous owner. threw in the 27.5 and it went like a raped ape.... Quote
thek5king Posted July 13, 2011 Author Report Posted July 13, 2011 Ive already put the 27.5s in and it helped out quite a bit...Ive discovered that fouled plugs seemed to be causing the misfires but I doubt they are causing the backfiring..... Quote
volcrano Posted July 13, 2011 Report Posted July 13, 2011 Ive already put the 27.5s in and it helped out quite a bit...Ive discovered that fouled plugs seemed to be causing the misfires but I doubt they are causing the backfiring..... leakdown will not hurt to do.u check ur plug caps?tight,rusty?flywheel is clean and gap is good?are slides synched correctly in carbs?carb tops tight?silencer packing clogging outlet on left side?u sure reeds sealing correctly and not cracked?did u swap coil wires yet?definately super lean with 240.ull be 290-280 when ur done.check ur grounds.my buddy had a bad stator ground and it did that shit for a while.took forever to figure out since it was internittent. Quote
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