americanmusc1e Posted July 3, 2011 Report Share Posted July 3, 2011 My banshee seems to run really good when I'm riding by myself.... but when I race my buddies almost stock YFZ450 it just can't keep up... we have raced on pavement with full traction and even if I leave him off the line he still chases me down...... we also race 250' dirt and his times are consistently 1-1.5 seconds faster The banshee seems to run hard with no flat spots in acceleration or bogging. I'm not the best driver but I don't think its just my driving skills either. I thought my jetting might be off, but its really close now. I was running just a little too rich (The smoke ring was about 3-4mm wide and about the right color brown) but I changed the mixture ratio from 32:1 to 20:1 (which is about the same as dropping 1-2 jet sizes). I think the jetting is really close now. more info on the carb stuff I did here:http://bansheehq.com/forums/index.php?showtopic=144636 both pipes seem to kick on at the same time and I just checked the carbs to see if they were out of sync I did a compression test and got 170 psi on both cylinders. I have no Idea what to check next.... Clutch??... it dosen't seem to be slipping..... anything else??? His YFZ has: Slip on FMF exhaust, K&N, Dropped one tooth on the sprocket...... that's it.... no hidden tricks... I've seen him loose to fully piped YFZ's I have: stock stroke welded crank motor on 2nd oversize FMF Fattys HJR Dune Ported Cylinders 19cc swirl-cut domes...... Trinity Stage IV coolhead +4 timing mod stock reeds and cages stock carbs w/TORS delete cable...... 350 mains...... 27.5 pilot K&N filter with modded airbox running 20:1 Yamalube 60% VP racing C12 and 40% 93 octane pump gas I run 14/43 sprockets and 20" paddles or 22" dirt devils (14/43 brings me really close to the stock ratio with 22" tires) Quote Link to comment Share on other sites More sharing options...
Paulie B Posted July 3, 2011 Report Share Posted July 3, 2011 My banshee seems to run really good when I'm riding by myself.... but when I race my buddies almost stock YFZ450 it just can't keep up... we have raced on pavement with full traction and even if I leave him off the line he still chases me down...... we also race 250' dirt and his times are consistently 1-1.5 seconds faster The banshee seems to run hard with no flat spots in acceleration or bogging. I'm not the best driver but I don't think its just my driving skills either. I thought my jetting might be off, but its really close now. I was running just a little too rich (The smoke ring was about 3-4mm wide and about the right color brown) but I changed the mixture ratio from 32:1 to 20:1 (which is about the same as dropping 1-2 jet sizes). I think the jetting is really close now. more info on the carb stuff I did here:http://bansheehq.com/forums/index.php?showtopic=144636 both pipes seem to kick on at the same time and I just checked the carbs to see if they were out of sync I did a compression test and got 170 psi on both cylinders. I have no Idea what to check next.... Clutch??... it dosen't seem to be slipping..... anything else??? His YFZ has: Slip on FMF exhaust, K&N, Dropped one tooth on the sprocket...... that's it.... no hidden tricks... I've seen him loose to fully piped YFZ's I have: stock stroke welded crank motor on 2nd oversize FMF Fattys HJR Dune Ported Cylinders 19cc swirl-cut domes...... Trinity Stage IV coolhead +4 timing mod stock reeds and cages stock carbs w/TORS delete cable...... 350 mains...... 27.5 pilot K&N filter with modded airbox running 20:1 Yamalube 60% VP racing C12 and 40% 93 octane pump gas I run 14/43 sprockets and 20" paddles or 22" dirt devils (14/43 brings me really close to the stock ratio with 22" tires) If you put it in first and slowly roll on the throttle on pavement does it go into the powerband smoothly and rev out real good? At anytime is there a dead spot or sputtering in the rpm range? Those pipes are low end pipes good for trails but not really race winning. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted July 3, 2011 Report Share Posted July 3, 2011 bullshit fatties perform well enouph to take out a yfz and many other thing in the rite hands,there is no need for a 20:1 mixture unless your on alky,32:1 is plenty oil Have you plug chopped it yet it takes 5 minutes and says alot,Also i try to not be a chemist if your bike needs 100oct buy 100,mixing vp an pump fuel is not the best one is man made one is not Quote Link to comment Share on other sites More sharing options...
06specialedition Posted July 3, 2011 Report Share Posted July 3, 2011 Quote Link to comment Share on other sites More sharing options...
bansheeboy44 Posted July 3, 2011 Report Share Posted July 3, 2011 bullshit fatties perform well enouph to take out a yfz and many other thing in the rite hands,there is no need for a 20:1 mixture unless your on alky,32:1 is plenty oil Have you plug chopped it yet it takes 5 minutes and says alot,Also i try to not be a chemist if your bike needs 100oct buy 100,mixing vp an pump fuel is not the best one is man made one is not Definitely too much oil in the gas and you sound too rich on the main jet. I'd think you should be in the 330 range for mains Quote Link to comment Share on other sites More sharing options...
fastquad02blaster Posted July 3, 2011 Report Share Posted July 3, 2011 I would say that your jetting is probably right. I'm not ported and am running 330 main. Yeah, I would run 32:1 on your fuel/oil mix. Clymers says 24:1 but no need. Just wastes oil. You might be a little bit too rich still. You might be running too much octane. Too much will make it run worse too. You could try bumping up your timing 2* more and go with the fuel you're running. Good luck with it. You should be spanking that YFZ. Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted July 4, 2011 Author Report Share Posted July 4, 2011 I swapped in my 340 main jets. The only sizes I have are 350, 340 and 300 (the 300's were on the bike when I got it). and the local Yamaha dealer doesn't stock mikuni main jets bigger than 280 or so. I have to order any jets I get. here is what I got.... now I'm really confused.... what does this mean?? Quote Link to comment Share on other sites More sharing options...
zach15 Posted July 4, 2011 Report Share Posted July 4, 2011 i think the swirel cut head does nothing at all because u want the combusten to get in an out and not take its time spining around its better just to cut a .65 off the stock head and have the chamer reformed or do it ur self if you know what ur doing Quote Link to comment Share on other sites More sharing options...
sangheraent Posted July 4, 2011 Report Share Posted July 4, 2011 I highly doubt its your jetting. your picture of the plug isnt the best but it looks lean. if your bike seems to run without bogging and sputtering your bike with those mods should be running train all over that yfz. its even more unusual that his bike 5 speed catches up to your 6 speed. my stock banshee used to lose bad against my friends yfz but at 6th gear pinned was when the banshee catches up due to the extra gear. your beating him off the line but he catches up to you, tells me its most likely a gearing issue or your bike just doesn't have the power it should. my stock banshee wit toomy t5s and k&n used to be neck and neck with my friends piped yfz. and iv ridden a banshee with fatty's they are no joke. have you checked your electrical system? also do you loose coolent at all? iv lost power with a blown cdi box once, and an oring went on my cool head and lost some power that way. however the cdi problem will make it hard to start and the coolent one well your bike will blow eventually. check your stator also could have a weak spark. Quote Link to comment Share on other sites More sharing options...
toytech Posted July 4, 2011 Report Share Posted July 4, 2011 my Fast racing ported 4mil had no top end with the fatty's I put some R2 pipes on it and re jettet and it is a monster now. amsoil dominator oil mixed 50 to1 is what I use, with great results. Quote Link to comment Share on other sites More sharing options...
RagunCajun Posted July 4, 2011 Report Share Posted July 4, 2011 (edited) My buddy has FMF fatty's on his banshee before it was ported. Strait up garbage to ride. But that doesnt mean they are bad pipes. They are good pipes. Id like to see some videos of you racing your buddy and you racing by yourself. I want to see how good you are speed shifting, shifting, launching, riding etc. Driver skill is huge on a banshee. Id hate to recommend other mods if the problem is you. And 170psi seems high. Some lower octane race fuel perhaps might bee needed. But if you arent detonating, then i guess you are fine. Compression gauges vary. Mine was at 169.5 and i melted my pistons. As for running a train on that yfz450, not in all cases. There's a lot of variables here. Edited July 4, 2011 by RagunCajun Quote Link to comment Share on other sites More sharing options...
americanmusc1e Posted July 5, 2011 Author Report Share Posted July 5, 2011 Alright..... I'm not sure on the domes... I'll have to check on that.... or Maybe 19cc's domes provide too much compression and its heating up the air too much I can't ride WFO in sixth gear really because my front tires are really bad.... they are #1 on my list to replace....... they start shaking about 50-60mph and they show signs of dry rotting ... I don't want to push them that hard..... the 13/43 gearing with 22" tires returns me to the factory 14/42 gearing on 20" tires....... on the 20" paddles its barely more than dropping one tooth on the front sprocket I haven't check the electrical system.... but the bike usually starts on the 2nd kick on a completely cold motor with the choke pulled...... on a warm motor it kicks over the first time with no choke...... how do you check a stator??? I don't loose any coolant at all...... I'll try to get some videos this week...... Quote Link to comment Share on other sites More sharing options...
jackass_25 Posted July 5, 2011 Report Share Posted July 5, 2011 Something seems weird here bud. i have almost the same mods but without the head and domes and my Shee is crazy. 20:1 oil mix is way too much imo, i run 40:1 Klotz, also i believe ur jettin it too rich, im at 2000ft with 300 mains and 30 pilots (donno ur elevation). i run 15/41 sprockets with 22" tires cuz it would spin to 5th gear on loose dirt or pull the front end off the pavement in 4th. sounds like somethings not right to me. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted July 5, 2011 Report Share Posted July 5, 2011 my jetting didnt change going from stock cylinders and t5's to agressive dune ported cylinders and r2's. Quote Link to comment Share on other sites More sharing options...
camatv Posted July 6, 2011 Report Share Posted July 6, 2011 kinda interesting how all that happens.. how much do you weigh?? if your a big ole fatty like me the bike may just be slow,. or you have other issues going on i'd also love to see a video of you riding the bike. and i agree DITCH the stinkin yamacrap and the 20-1 thats a LOT of oil its going to make your main jets need to be much bigger due to the overly oily fuel mix. the swirling in the head is an attempt to make more turbulence in the squish and thats something you do want.. in my opinion the trinity's domes aren't cut deep enough to really make that much of a diff. a bike like that should be able to at least hang with a yfz . last year i had a 350cc ported with sst' fatty's on it it ran very very good. good enough to mess with some larger motor's.. the propblem is not necessairly the pipes. Quote Link to comment Share on other sites More sharing options...
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