Gobbler Posted April 4, 2004 Report Posted April 4, 2004 Guys, I have a basically stock 2001 banshee except for a K&N pod filter running no air box and a Dynojet rejet kit in the carbs for the K&N filter. The bike has been running sweet for 2 years with the standard pilot, Dynojet needle's in the middle clip and 280 mains @ sea level. The problem I have is recently while at the end of a 3 hour race the bike started to bogg in 5th and 6th at WOT. The bog wasn't there for the first 2 1/2 hours for the race. I was leaning towards an electrical problem because from carting experience a motor wont go out of tune instantly due to jetting. I bought new plugs and also took the stator cover off and cleaned the top and bottom ignition pickup strips and also the magnetic sensor as they were both fairly rusted. This helped it a little by moving the bog a bit higher up the rev range now but theres still a bog at WOT in 5th and 6th. My question is do I chase the jetting now or should I still be looking electrically ? I've ordered some 290,300,310 mains just incase but wouldn't mains that high be getting a bit crazy for only small intake changes ? Cheers Quote
bbluebanshee Posted April 4, 2004 Report Posted April 4, 2004 you may want to check your compression. a three hour race, i am sure, plays hell on a motor!! but i think you are right about the jets. you shouldnt notice any change considering your bike was running fine. if you are getting spark in the lower gears, i dont see how the higher gears would make a difference. how clean are your air filters? Quote
Gobbler Posted April 4, 2004 Author Report Posted April 4, 2004 I did a compression test and I got ~ 125 psi in each cylinder. When I first got the bike new I did a test and it had ~133 psi. Not bad for a nearly three year old engine. What I did notice was it took more kicks for the left cylinder to get up to 125 psi than it did the right side. Proberly twice as much really. Not sure whats going on there ? Anyway, the air cleaner was pretty good, It uses an outerware and that keeps it pretty clean. I just took the bike for a quick ride around the block then and noticed that when it bogs at WOT in 5th, if I pull the choke out to the second click, the motor pulls again and I can get into 6th and still pulling. This would indicate the mains are lean. But then it goes back to the fact of the jetting changing during a race which it shouldn't off. The elevation at the track is the same as my house so I ruled that out. Quote
bbluebanshee Posted April 4, 2004 Report Posted April 4, 2004 well, it sounds to me, you may want to change you'r mains. i dont know why you should need to, but if you have to pull you'r choke out to get a bit more gas, then i thing some mains are in order! Quote
bbluebanshee Posted April 4, 2004 Report Posted April 4, 2004 how does you'r plug look after running w/o? shut it down immediately after and you should have a ligt to med. brown color. any lighter and you are running too lean. Quote
Gobbler Posted April 4, 2004 Author Report Posted April 4, 2004 Yeah Blue, the left side is like a light grey and the right side light brown. Looks like the left sides lean but the rights fine. I cant just put a bigger main in one carb, must have issues inside the engine for it to do that ? Quote
Banchetta Posted April 5, 2004 Report Posted April 5, 2004 Check for air leaks. Spray some wd40 around the carb boots and see if the motor revs up...that would indicate a leak....Both plugs should look exactly the same..You might want to pull the carbs and clean them thorouly w/ an air compressor... Quote
banshee tuner Posted April 5, 2004 Report Posted April 5, 2004 Could be an air leak or a clogged main jet. But a true compression check is w.o.t. and only 5 solid kicks. If your kicking one side twice as much you have low compression on that cylinder. Check again and kick both sides 5 times at wide open throttle. Quote
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