CarvedArt

Missing some info: Carb Type, Current Jet Size, Temp, Humidity, Premix Ratio. Porting = Too many variables to guess Airbox No Lid = +1 to 2 on the Mains +4 Timing = +0 to 1 on the Mains Ported Cages = +0 to 2 on the Pilots & +0 to 1 up on the Needles T5's = +7 to 8 on the Mains & +0 to 1 down on the Needles Try this PINNED Topic to find your setup: http://bansheehq.com...showtopic=99361

Just in case... the TORS "brainbox" is the little black box w/ a 3-wire connector mounted on the upper-left front cross-member of the frame just under the front of the gas tank. Regardless of the jet size you can't really adjust your idle by changing jets alone. With the Boyesen's, K&N's, and T6's you should probably be running the 27.5 pilots. Depending on your porting you may want to retard your timing back to +4 as well (retard = more top / advance = more bottom). You might have too much advance for a good idle; I doubt it but every bike's different and +4 is a great safe place to start. Unfortunately if you're still rockin the TORS tops you're going to have to adjust the idle using the idle screws on the tops. The TORS tops are originally set at the factory and not very friendly to adjust but not impossible either. The procedure goes something like this: You need to lightly seat the Air Screws Then back them out 2-turns Warm-up the engine Adjust the idle using the TORS Idle Speed Adjust Screws (to about 1500 rpm). You have to adjust them both equally as they directly affect carb sync. (If you have a sync tool this is the time to use it!) Then you can adjust the Air Screws to fine tune your idle to low-end revs If your pilot is right you should end up between 1 ~ 2-turns out on the Air Screws When you're finished you should also have about a 1/4" of free play in the throttle cable

The stock carb is: Mikuni VM26SS Spigot (round-slide) The stock Jet Needle is: 5N7 1st character = needle length (5 = 5 Series, 50.00-59.99mm) 2nd character = amount of taper in 15 min intervals (N = 3 degs 30 mins) 3rd character = materials and finish (7 = [exact length, major OD, point of beginning of taper in reference to clip position, manufacture specific]) To get fatter you need to do one or more of the following: Move the clip down on the needle (position 4 or 5) You can also use "half-height" washers under the clip to get a little fatter as well Get a needle with more taper (greater than N) The other half of the Jet Needle equation is the Needle Jet which is the "tube" that the Jet Needle mates with (slides/fits into) The stock Needle Jet is: 182 Series A larger Needle Jet (larger orifice) will also fatten the mix. (LEANEST [N-0 through Q-8] RICHEST) Are you sure you need fatter needles? If you're sure you need fatter needles I would suggest contacting an expert in the field not someone who's just selling parts. You might try: www.motorcyclecarbs.com

I would guess that your Pilot Jet is too large, you might want to try a 27.5 or even the stock 25. General rule of thumb: If the air screw is less than 1-turn from Closed, it needs a larger Pilot Jet If the air screw is more than 2.5-turns from Closed, it needs a smaller Pilot Jet

The carb is made-up of 4 main circuits that overlap each other: 0 - 1/4 = Air screw & Pilot Jet (The brass screw on the left-side of the carb, in = rich/out = lean; & little brass "screw" on bottom of carb, inside fuel bowl, next to the main jet) 1/8 - 1/2 = Throttle Valve (The angle cut on the leading edge of the carb slide) 1/4 - 3/4 = Jet Needle (The needle in the center of the carb slide, clip up = lean/clip down = rich) 1/2 - Full = Main Jet (Brass hex on bottom of carb, inside fuel bowl, next to the pilot jet) So if your having issues from 1/2 to full then you're looking at the Jet Needle and the Main Jet as well as your Float setting. "Smokes alot" could be related to your premix-ratio and/or your jetting being too rich or a coolant leak (depends on the color/smell: whitish/sweet=coolant; blueish/greyish=oil, sweet=premix, foul=case). You must make sure your floats are set correctly (21mm from the gasket surface, (not the gasket), touching but not compressing the needle valve bumper) When an air-fuel mixture is too rich: The engine noise is dull and intermittent Condition worsens when the choke is opened Condition worsens when the engine gets hot Removal of the air cleaner improves the condition Exhaust gases are heavy/oily Plugs foul When an air-fuel mixture is too lean: Engine overheats Condition improves when the choke is opened Acceleration is poor Engine RPMs fluctuate and lack of power is noticeable Plugs burn You should also sync your carbs. Rough Calcs... Stock Mains = 210 (plus/minus 10) Boost Bottle = No change (Make sure the rubber intake isn't cracked around the bottle holes) K&N w/ airbox = 4-6 Larger Mains & 0-1 Larger Pilots Boyesen Reeds = 0-2 Larger Mains

In drag racing (on dirt) your always WOT - like Dave said. There is no power to be made at less than WOT. However, I can see where badly unsync'd carbs would affect a run due to one cylinder loading up, or not cleaning out as good as the other in pre stage. I noticed that you've caveated your reply with "(on dirt)" and so I have to admit I'm NOT an expert in 2-stroke dirt drags, most of my drag experience is on the pavement; both bikes, to include an 87 Kaw Mojave with a .40 over KZ1000, and cars (currently running a Z-28 in IHRA Super Rod (9.90 1/4mi)). I used to run an Inglese manifold on a BBC 461 with 8 51mm EMPI's which is where I REALLY learned what syncing carbs was all about; not a Banshee but sure ran like one! I can tell you first-hand when those babies were out of sync, I staged with a 4500 stall, the moment I let the transbrake go @ 5000 she would hesitate before the wheels lifted; mind you that setup took more than a few minutes of my life to tune and sync. I work in aerospace and I'm pretty steeped in theory, design, and test and I've taken what I've had the privilege to observe/learn and applied it to my motorsport hobbies. So please take what I say with a grain of salt, folks like Dave and yourself actually have the hands-on 2-stroke drag experience and that's something that math can't always predict. You've definitely gotten my curiosity up though, I'd be very interested in real-world results of ETs between a drag motor with carbs synced vs. carbs unsynced (or synced by eye); something like 3-5 runs unsynced vs. 3-5 synced (same bike of course). Might even be worthy of its own topic to see what real bikes run within a specific distance capturing actual numbers before and after sync. Thanks for adding your experience/expertise on this subject, I'm huge fan of learning from the experiences of others; it many times save me from misallocating my own hard earned cash! Seriously, you guys are the reason people are still riding/racing Banshees around here, without you guys we'd all be doing a lot of head scratching and guessing.

The air screw is effective across the entire range of circuits, however, has most effect on the pilot circuit (0 - 1/4). So based on your comment that your "idle is smooth and even, starts easily and pulls pretty good," I'd say your air screw and pilot jet are correct. You may very well be right about compensating for something elsewhere, at least a little bit, you're compensating for machining/casting tolerances within the carbs and intake tract; the manufacture has allowable tolerances for each of the parts that they machine/cast plus or minus x-number of thousandths. No two carbs are exactly identical, one might have an extra little indentation in the bore that equates to increased volumetric capacity, while another might have an extra little flashing interfering with flow. Also, typically slides will not rise perfectly square with the bore as the cable pulls the slides will usually drag slightly on one side. So while measuring the slide height that you can see with your eye will get you close enough to start and run it will NEVER be at the top of its game. So I really wouldn't say you were compensating for problems as much as calibrating your intact tract for optimal volumetric efficiency. The higher the volumetric efficiency the greater the potential for running higher RPMs which equates to potentially higher HP. Its not as simple as saying get a sync tool and get more HP. There are TONS of factors that play into these equations to include calculating the optimal resonance amplitudes and frequencies to design your expansion chamber accordingly to attempt to create a volumetric efficiency as close to 100% or higher as possible; which is no simple task. All that being said, I have a sync tool and swear by it; but if you can't afford or borrow one your not going to suffer from major damage. I should reiterate though, if you can, you should! You will notice a seat of the pants difference. To piggyback on dajogejr's comments about... I'd say you'll suffer from performance loss at any level of riding, my point about the drag racers is purely referring to the fact that the only reason your racing is to win and if you can't deliver power down low before WOT you will lose tenths and that could cost you a win. If your "just" riding around the dunes/trails you can't lose any race that your not in. My original post was intended as more of a warm fuzzy to those that can't afford one or can't borrow one. I wouldn't ride mine without syncing and if you can get your hands on one it's well worth your while. It's one of the easiest Banshee "upgrades" available.

First check the Pickup Coil gap it should be between .015 - .020 (about the thickness of a matchbook cover) ------- Use an Ohm meter: Test the primary coil resistance between the 2 blade connectors on the coil you should get .28 ~ .38 Ohms If the primary tests bad, replace the coil ------- Test the secondary coil resistance between each of the blade connectors and the corresponding plug wire; each one should be between 4.7 ~ 7.1 Ohms If the secondary tests bad, remove the spark plug boots and test without them. If the secondary tests good, replace the spark plug boots. If the secondary still tests bad, replace the coil. ------- If both of these are good check the stator next: Disconnect the magneto connector (4-wire; GREEN, RED, WHITE/RED, WHITE/GREEN) and check the resistance between the GREEN and RED you should get between 13.7 ~ 20.5 Ohms If the stator tests bad, replace the stator assembly.

If you've modded the TORS system, and if you haven't already done so, disconnect the TORS Control Unit (little black box on the front-upper left-hand-side of the frame, just under the tank; single 3-wire connector). Here's something that might help... Connections: Ignition = RED + RED/BLACK Coil = ORANGE (+) & BLACK (-) Voltage Reg = BLUE + BLACK [To Frame Gnd] CDI: WHITE/GREEN > STATOR (WHITE/GREEN) WHITE/RED > STATOR (WHITE/RED) GREEN > STATOR (GREEN) RED > STATOR (RED) RED/BLACK > IGNITION (RED/BLACK) BLACK/WHITE > KILL SWITCH (BLACK/WHITE) BLACK > WIRING GRD (BLACK) ORANGE > IGN COIL (ORANGE) Stator: YELLOW > VOLTAGE REG (YELLOW) & DIMMER SWITCH (YELLOW/RED) BLACK > WIRING GRD (BLACK) Do Not Connect (Open Circuit -OR- Tether Switch): Kill Switch = BLACK/WHITE + BLACK Removable T.O.R.S. Junk: Control Unit = YELLOW/BLACK + BLACK + BLACK/WHITE Throttle switch = BLACK + BLACK/YELLOW Carb Switch A = BLACK/YELLOW + YELLOW/BLACK Carb Switch B = YELLOW/BLACK + BLACK Lighting: Headlights = GREEN + YELLOW + BLACK Taillight = BLUE + BLACK

You can get it close enough by using your calibrated eye to run good enough for everyday fun. You can use your hand also, lightly place a finger on each of the slides and press the throttle then feel the drag, you should feel the slides lift at the same time. The deal with the sync tool is that it measures vacuum, where your eye measures nothing. It's like cutting a piece of paper into a square, can you get the paper to be square without a ruler? Of course; will it be a perfect square? Your chances are pretty slim. Could you cut a perfect square with a ruler by measuring each side? Your chances are far greater. It's just something to help you get your carbs closer to perfect sync; your carbs could be synced within several hundred-thousandths doing it by eye vs. maybe a few thousandths or less by using the sync tool. Will you achieve a higher horsepower by using the sync tool vs. your eye? Definitely, your essentially making more efficient use of the available fuel being delivered by the carbs. One carb will be leaner (like by about one gnats butt or so) and flow more volume than the other. Will it blow your motor? Highly doubtful. Will it be noticeable? It all depends on how far off your calibrated eye is. If drags are your gig, where every tenth counts, I wouldn't go without the tool; if riding for fun is where you're at, I'd say as long as your darn close, your close enough. I almost forgot, you can also use a couple of drill bits to sync your carbs. Just get two bits that are the same size and their diameters are taller than the current openings, at the base of the slides, at zero throttle. Insert the backs into the carbs lifting the slides, increase the throttle position until the throttle is above the idle settings and just rest on the bits. (Keep the throttle pulled.) Even-up the cable slack and work the bits like feeler gauges, each one should have the same "pull" force. When they "feel" good you should be synced.

You have to start with a little slack in your cable so that the idle screw is the only thing affecting the RPMs while you sync the idle. In other words if you backed out the idle screws completely the slides should bottom out. Adjust the idle screws until you get the same reading on both carbs. Once you have the carbs synced at idle; tie a string, tie wrap, rubber band, or the likes to keep the throttle about 1/4 open (3-5K rpms). Adjust the carb top cable adjusters until you get the same readings on both carbs. At this point you can remove the implement holding the throttle open and check the cable slack you should have a little free-play between where the throttle is at rest and where it begins to add fuel (about an 1/8"). Once this is done your carbs should be in sync. Take it for a spin, if one side comes on before the other just lift the opposite side ever so slightly until they both fire in unison.

I got the schemes straight from Yamaha's site and you're right I do remember my 87 having a red seat, actually sightly orangy-pink. I also found a typo in the index (troubleshooting) that I've since corrected. The other part that still needs work is the VIN decoder, it will decode the VINs but the VDS section is populated with 'educated guessing' it will definitely give you the right year and whether or not it gets a CA green sticker. Additionally, the sheets are locked with a blank password if anyone's interested in making their own changes. As for the file itself, I would be more than happy to upload the file directly except the site (BHQ) would not allow the file size. If someone knows how to get it uploaded directly I'm all ears. Also, thanks to everyone who's found this useful, and if there's anything wrong, needs to be changed, or should be added, let me know and I'll see what I can do.

BDT v1.0 I put together a little spreadsheet (requires Excel 2007 or higher) to help Banshee owners perform many of the frequently asked calculations and tasks. Hopefully someone will find it useful, this is version 1 and any suggestions are welcome. Of course this is provided "as is" and without warranty or guarantee of suitability. http://www.4shared.com/dir/JGdLyFR1/Banshee_Digital_Toolkit.html I've corrected a typo, corrected the color of the 87, and added a carb sync how to. The Banshee Digital Toolkit 1. How to Jet a Banshee 2. Banshee Jetting Calculator 3. Quick Specs 4. Needle Jet Specs 5. How to Sync Carbs 6. Color Options by Year 7. VIN Decoder 8. Speed Calculator 9. Horsepower Calculator 10. Pre-Mix Ratio Calculator 11. Chain Length Calculator 12. Displacement Calculator 13. Mikuni Troubleshooting 14. Wiring Schematic 15. Banshee Jetting FAQ 16. Carburetor Theory 101

I'm assuming that you don't have a buffing wheel... If it's not all rusty you can just use a soft cloth and something like Brasso. If it's all rusty and as long as the chrome hasn't started flaking or peeling you can rub it down with crumbled-up aluminum foil and Coca-Cola, then follow it up with some chrome polish. Sounds crazy but it works really well. If your looking for someone else to do it for you most bike shops (Harley or customs) have buffing equipment and will buff it for a fee.

They shouldn't be that far out. But what I like to do is sync 'em by eye then ride it around for a bit before I get on 'em with the sync tool. I have found that they will move some after you first get 'em put back together due to the spring and the cable not being fully seated in their "homed" positions. I think that the spring shifts a little and can relax some of its tension if you put it in the slide and then you have to rotate it one way or the other to line it up. Same with the cable it could be slightly twisted one way or the other until you pull it a few times. Also, you have to make sure that you have the cap tight and if you don't have the TORS, make sure the cable ends are completely seated in the caps (dirt free) with the boots pulled down.

Thanks for the input! I'm in the 80deg's right now, normally average between 80 - 95. So I guess I'll start with the 300 Main, 3 on the Needle (middle), 27.5 Pilot, and 1.5 turns on the Air. As for the sync I've got an EMPI (snail) so I'm keeping that in check too. Thanks again.

I have a stock 97 and I just added a few mods. I'm just looking for some reasonable place to start as far as jetting is concerned. Stock carbs TORS removed idle kit installed Mix = 32:1 Elev = 3222 ft asl Humid = 0-30% Base jetting: Slide = 2.0 Pilot = 25 Needle = Y151, 3rd groove from top Main = 200 Air = 1.5 turns ...Ran perfect. Added/Modded: Switched the coil leads, put the pos on the (+) and the neg on the (-) Toomey T5's w/ sparkys Toomey 2:1 High Flow Air Filter Toomey says: Pilot = 25 Needle = Y151, 4th groove from top Main = 280 or 270 for higher elev Air = 1.5 turns Elev = Sea Level My math says: Pilot = 25 - 27.5 Needle = Y151, 3rd - 2nd groove from top Main = 290 - 310 Air = 1.5 - 2 turns What jets should I start with? ...Thanks for your help!

I got a set as well. Only issue I had was the mounts were slightly bent during shipping. To straighten them out I just clamped them between 2 blocks of wood. Outside of that I had to cut about an inch off of the lower hose (engine-end) to keep it off of the pipe (T5). Overall quality is on-par with the higher priced radiators and hoses, the welds are decent, porosity is minimal, the cap has a cheap little foil chain to keep it attached to the radiator when it's removed, fitment is good, and does what it's supposed to.