yamaha driver Posted November 17, 2016 Report Posted November 17, 2016 I just picked up a 2001 banshee a couple of weeks ago, wasn't running right when I first got it and figured out the carb slides were in backward. Then I flipped them around it ran a little better but is running lean, starts right up with no choke but have to feather the gas a little to get going and won't rev all the way out. Haven't done an auctal plug chop but they are white after WOT runs and after idle. I bumped up the main jets from 300 to 340 with no difference in running or plugs, also put new NGK plug caps on.Engine is stock with toomey t-5 pipes and silencers, no air box lid with clean uni air filter. I was going to build a leak down tester but was wondering if a bad stator could cause it to show a lean condition? It doesn't seem to get that hot, but just sounds like it's still cold when you try to rev it out. I compression tested it but I believe it's my broken tester since both were at 75psi but kicks over harder then my old banshee. Going to pick up a new one tonight. Any help is appreciated! Quote
RIPPIN' IT UP Posted November 17, 2016 Report Posted November 17, 2016 340 mains will be way to rich for those bolt on mods regardless of temp & altitude, which you have neglected to mention. Also what pilot is in it, it may be the cause to having to feather the throttle. The fact that it isn't revving out could also be caused by a rich condition from to larger mains. Any other mods like reeds, timing plate, etc & getting an accurate compression test could save lots of time & money. Sent from my ZTE T84 using Tapatalk Quote
yamaha driver Posted November 17, 2016 Author Report Posted November 17, 2016 (edited) Sorry forgot that, 1200ft 40 degrees . Boysen reeds tors delete, parking brake delete, ignition delete but no other mods that I know of, 27.5 pilot. Ran the same with the 300 jets but got hot quicker. But it will start up first kick and idle pretty decent. Edited November 17, 2016 by yamaha driver Quote
RIPPIN' IT UP Posted November 17, 2016 Report Posted November 17, 2016 27.5 pilot & 300 mains should be pretty close, differently need to compression test it & if that checks out a leak down test. Sent from my ZTE T84 using Tapatalk Quote
yamaha driver Posted November 17, 2016 Author Report Posted November 17, 2016 (edited) Alright I'll pick up a new tester and try that first. What should be a good psi for stock engines? Edited November 17, 2016 by yamaha driver Quote
RIPPIN' IT UP Posted November 17, 2016 Report Posted November 17, 2016 100 to 120psi any below 100 should be looking at a rebuild. Sent from my ZTE T84 using Tapatalk Quote
yamaha driver Posted November 17, 2016 Author Report Posted November 17, 2016 Ok thanks, would just needing a rebuild make the plugs white tho? Quote
RIPPIN' IT UP Posted November 17, 2016 Report Posted November 17, 2016 No it shouldn't, I'm thinking most likely a intake leak somewhere, which will be found with a leak down test. But compression test still can't hurt will give you an idea of what condition the top end is in. Sent from my ZTE T84 using Tapatalk Quote
yamaha driver Posted November 17, 2016 Author Report Posted November 17, 2016 Ok I noticed a little cracking on the intake boots but they aren't that big, I'll have to pick up both and do some testing. Quote
RIPPIN' IT UP Posted November 17, 2016 Report Posted November 17, 2016 Yeah without checking any of these things, you would be just flying blind. Sent from my ZTE T84 using Tapatalk Quote
Ayesully810 Posted November 18, 2016 Report Posted November 18, 2016 Ok I noticed a little cracking on the intake boots but they aren't that big, I'll have to pick up both and do some testing. Once you do a leak down you will know if those cracks are "not that big" or not 1 Quote
trickedcarbine Posted November 19, 2016 Report Posted November 19, 2016 Ok I noticed a little cracking on the intake boots but they aren't that big, I'll have to pick up both and do some testing.Major problem. Like a hole in a piston problem. Quote
yamaha driver Posted November 22, 2016 Author Report Posted November 22, 2016 (edited) Well I leak down tested it and it held pressure through the 6min.. With only small leak around where I put the plugs in the intake boots. Never picked up a new compression tester but both pistons and cylinders look good with no scoring from what I can see through the exhaust ports. Sprayed soapy water on everything and only bubbles were there. Edited November 22, 2016 by yamaha driver Quote
yamaha driver Posted November 22, 2016 Author Report Posted November 22, 2016 Well I shouldn't say it held complete pressure it dropped a needles worth of pressure. But with little bubbles around the rubber plugs it seemed reasonable. I'll try to get them to seal in there better tommorow and retest but wouldn't it drop more if there was an air leak somewhere else? Quote
yamaha driver Posted November 22, 2016 Author Report Posted November 22, 2016 Well I just slapped the carbs back on and I noitced with the clamps all the way tight the carbs still turn in the boot with little force. So maybe the clamps are the wrong ones or just old? They look like the stock ones since they have the little notch for the top of the intake boot. Could that be the air leak? I'll see if the Yamaha dealer here has some new clamps and try that Quote
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