tuck1371 Posted February 25, 2012 Report Share Posted February 25, 2012 So I got a little bored tonight and decided to tear into my new (to me) Banshee. I've had it a week now and had to know what I had... Here's what I've found. I could obviously tell it had a Prodesign Cool Head on it... took it off and found that it has 19cc domes. While the head was off I mic'd the cylinders and got a measurement of ~66 mm on stock jugs. It shows evidence of port work, but how aggressive it is I don't know. (I'll try and get pics tomorrow, phone was dead tonight or else I'd have some.) I crossed my fingers, danced a jig, said a prayer but all that didn't put a timing plate in... So no adjustable timing. That is all what I learned this evening... now for what I know is it has a K&N air filter with the pro flow attachment in a stock box, Toomey T5 pipes, stock Mikuni carbs (I think. I mic'd the bore where it slides into the intake boots and it measured just shy of 28mm. Can get pics tomorrow too if need be...), uhh... I think that's really about it performance-wise. Now on to my questions... Is 91 octane fine for this setup? What fuel/oil ratio would you recommend? How much overbore is too much on stock jugs? How do I tell what size jets I have (and any jet recommendations?)? Hell, even before jets... do I have enough carb or should I be looking for bigger? Timing plate is a must-do from what I've picked up on here so far, any naysayers to that? Would changing timing affect what jetting I needed? I'm planning on making the drive up to FAST tomorrow morning, I'll probably have my carbs in tow to figure out what I'm working with there. If there's any more info you need from me, please let me know and I'll get what I can to ya. Sorry if this is too noob-ish of a post, I'm completely new to the Banshee world and I really don't wanna blow this thing up to learn the hard way that something wasn't right. My prior experience has been on a piped and jetted YZ125. Any help/input is greatly appreciated! Quote Link to comment Share on other sites More sharing options...
Worstenemy453 Posted February 25, 2012 Report Share Posted February 25, 2012 So I got a little bored tonight and decided to tear into my new (to me) Banshee. I've had it a week now and had to know what I had... Here's what I've found. I could obviously tell it had a Prodesign Cool Head on it... took it off and found that it has 19cc domes. While the head was off I mic'd the cylinders and got a measurement of ~66 mm on stock jugs. It shows evidence of port work, but how aggressive it is I don't know. (I'll try and get pics tomorrow, phone was dead tonight or else I'd have some.) I crossed my fingers, danced a jig, said a prayer but all that didn't put a timing plate in... So no adjustable timing. That is all what I learned this evening... now for what I know is it has a K&N air filter with the pro flow attachment in a stock box, Toomey T5 pipes, stock Mikuni carbs (I think. I mic'd the bore where it slides into the intake boots and it measured just shy of 28mm. Can get pics tomorrow too if need be...), uhh... I think that's really about it performance-wise. Now on to my questions... Is 91 octane fine for this setup? What fuel/oil ratio would you recommend? How much overbore is too much on stock jugs? How do I tell what size jets I have (and any jet recommendations?)? Hell, even before jets... do I have enough carb or should I be looking for bigger? Timing plate is a must-do from what I've picked up on here so far, any naysayers to that? Would changing timing affect what jetting I needed? I'm planning on making the drive up to FAST tomorrow morning, I'll probably have my carbs in tow to figure out what I'm working with there. If there's any more info you need from me, please let me know and I'll get what I can to ya. Sorry if this is too noob-ish of a post, I'm completely new to the Banshee world and I really don't wanna blow this thing up to learn the hard way that something wasn't right. My prior experience has been on a piped and jetted YZ125. Any help/input is greatly appreciated! At 66m you are at .070. .100 over is where a stock cylinder should stop. You should have enough carb for that set-up but if you do want to upgrade you can do the Mikuni PWK 28's. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted February 25, 2012 Report Share Posted February 25, 2012 At 66m you are at .070. .100 over is where a stock cylinder should stop. You should have enough carb for that set-up but if you do want to upgrade you can do the Mikuni PWK 28's. 66mm is .080 over Quote Link to comment Share on other sites More sharing options...
toytech Posted February 25, 2012 Report Share Posted February 25, 2012 Jeff will steer you in the rite direction Quote Link to comment Share on other sites More sharing options...
ClayAiken Posted February 25, 2012 Report Share Posted February 25, 2012 Your gonna want to change to around 20-21cc domes for 91 octane other then that shee sounds pretty good. Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted February 25, 2012 Report Share Posted February 25, 2012 At 66m you are at .070. .100 over is where a stock cylinder should stop. You should have enough carb for that set-up but if you do want to upgrade you can do the Mikuni PWK 28's. You must be new to the Banshee scene. 66mm is a 2mm overbore (0.078") or 80 thousanths to the metric impaired. While they do sell 66.5mm pistons, I would stop before then. Mikuni PWK 28? Either you are referencing a Mikuni flat slide 28mm carb or a Keihin PWK 28mm carb. Now, to the OP... If you are close to sea level or feel you have poor quality fuel I would run a 21cc dome. 20cc if you are at a higher elevation or can get ahold of a quality 93 octane fuel. Do a search, you can ream out your timing plate for free, or you can usually find a nice aluminum adjustable timing plate for real cheap. Your money will be better spent on other parts before purchasing carbs. I suggest picking up an aftermarket water pump right away. Then, I would look into aftermarket suspension. Works shocks can be had for cheap and will make a BIG difference. Quote Link to comment Share on other sites More sharing options...
Worstenemy453 Posted February 25, 2012 Report Share Posted February 25, 2012 (edited) Ah i messed up. I know my banshee is a 65.5 at .060 over so i just went with the fact that .5 wouldve been a .070. Fail on my part haha. Sorry about the misinformation. EDIT: Yes i was referencing the Keihin 28 PWK's, i still had Mikunis on my mind for my build lol. Edited February 25, 2012 by Worstenemy453 Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted February 25, 2012 Report Share Posted February 25, 2012 So I got a little bored tonight and decided to tear into my new (to me) Banshee. I've had it a week now and had to know what I had... Here's what I've found. I could obviously tell it had a Prodesign Cool Head on it... took it off and found that it has 19cc domes. While the head was off I mic'd the cylinders and got a measurement of ~66 mm on stock jugs. It shows evidence of port work, but how aggressive it is I don't know. (I'll try and get pics tomorrow, phone was dead tonight or else I'd have some.) I crossed my fingers, danced a jig, said a prayer but all that didn't put a timing plate in... So no adjustable timing. That is all what I learned this evening... now for what I know is it has a K&N air filter with the pro flow attachment in a stock box, Toomey T5 pipes, stock Mikuni carbs (I think. I mic'd the bore where it slides into the intake boots and it measured just shy of 28mm. Can get pics tomorrow too if need be...), uhh... I think that's really about it performance-wise. Now on to my questions... Is 91 octane fine for this setup? What fuel/oil ratio would you recommend? How much overbore is too much on stock jugs? How do I tell what size jets I have (and any jet recommendations?)? Hell, even before jets... do I have enough carb or should I be looking for bigger? Timing plate is a must-do from what I've picked up on here so far, any naysayers to that? Would changing timing affect what jetting I needed? I'm planning on making the drive up to FAST tomorrow morning, I'll probably have my carbs in tow to figure out what I'm working with there. If there's any more info you need from me, please let me know and I'll get what I can to ya. Sorry if this is too noob-ish of a post, I'm completely new to the Banshee world and I really don't wanna blow this thing up to learn the hard way that something wasn't right. My prior experience has been on a piped and jetted YZ125. Any help/input is greatly appreciated! Things I would spend money on: FIRST and most important, a trued and welded crank. If your crank lets go you are going to be buying replacement parts for things you already spent money on. Second, mod your timing plate, you can do this for free. Third,get a billet impeller. Fourth,make sure your clutch basket is not loose, if it is and it is stock get a billet one, if it is already billet get some new cushions. Fifth, make sure the bushing on the kick idler gear is not sloppy, if it is sloppy it will knock the clip off sending it through the primary gears and causing more damage, the solution is a bushing from FAST. Sixth is shift modifications- modded star, modded shift shaft, and check out Mull Engineering's shift mods. Seventh, is a pancake bearing for the clutch, especially if you are running ATF in the gearbox. The guys running ATF are welding the clutch ball to the pushrod, I run Klotz Flex Drive 30 in mine and have never had this problem, however I will be installing pancake bearings in all of mine when they are apart next time. Other things to think about- get a service manual, TORS elimination kit, don't just spend money on your motor spend some on shocks, swingarms, A arms, lighting if you night ride, ergonomics, etc. You should always make your bike reliable BEFORE you make it fast as it can travel farther in a half hour than you can walk ALL day. Quote Link to comment Share on other sites More sharing options...
tuck1371 Posted February 25, 2012 Author Report Share Posted February 25, 2012 I appreciate all the replies! I went out today and picked up a few things for her, mainly maintenance items but also ordered a TORS eliminator. Called Jeff @ FAST and talked to him for a bit this morning. Wasn't able to make the drive there but definitely will soon. Did stop by JSR in Wichita and picked his brain a bit. All in all a semi-productive day. Learning all about my shee in leaps and bounds haha. I did find that the mains in the carbs were 270... Just from what i've learned i'm betting thats a little lean, huh? Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted February 26, 2012 Report Share Posted February 26, 2012 (edited) At 66m you are at .070. .100 over is where a stock cylinder should stop. You should have enough carb for that set-up but if you do want to upgrade you can do the Mikuni PWK 28's. 66mm is .080" over not .070". And Keihin makes the PWK carbs not Mikuni. NVRMND Edited February 26, 2012 by Strm Trpr Quote Link to comment Share on other sites More sharing options...
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