Hello gang, been reading here for a while, getting all the good info, finally decided to register and ask a question or two.
It's a 2003 Banshee we picked up used, that I suspect was never entirely tuned and jetted for the mods.
Toomey T5s, Reed spacers, Boost bottle, K&N airbox lid filter, breathes well and is unrestricted.
It ran "OK" when we first got it, of course what is "OK" when you have no benchmark?
It started easily, ran OK, nuff said. It began faltering getting worse, and that is when I discovered some whacked out carb air adjustments. Right side Air screw was almost all the way closed, left side was at 2 full turns out, whoa. Left side float valve leaked, knew that all along, also knew it would need the rebuild kit and new float needle/seat
Between my son and I we have owned Blasters, Warriors, i currently have a 660Raptor, the banshee is really my sons bike, so, we aren't strangers to mods and tuning, but this is the first Banshee, so we're getting our feet wet with Dual carbs and lots of jetting stuff.
Rough idle, hard starting, then pretty much no starting. Have remedied most of that stuff.
Did the normal outside checks, Checked for air leaks, ordered the Air filter adapter right away, we've owned at least 3 other Yamahas and know all about how crappy the Air filter fastening system is. Anyway, sprayed WD40 on intake boots, and reed spacers to make sure it didn't have an air leak.
From the looks of the tires, chains, sprockets, and eveything else this thing hasn't seen much riding. We swapped our Maxxis Razrs and Works shocks over to this bike.
Finally got inside the carbs, found 250 Mains and the stock 25 pilots. For the Toomey's and open Air Box lid 250s seemed pretty small. Toomey sez go to 280s, just for the pipes alone. I'm adding a little more for the open air box and cranked it up to 300's. Top End is WAY COOL now, just nothing but arm pulling power, butt sliding off the seat...you guys know the feeling. So we can't say anything bad about 1/4 to Full throttle range, it rocks!
Low end Bog has got us down, though. Starts first or second kick now, idles decent, but when you jump on the throttle is Bogs down, even will cut off if you don't feather it up.
With the stock 25s for pilots, we can start up, get it to idle, but it idles best with Air screws turned all the way in, maybe 1/4 turn out, max. Yeah, it makes sense tht pilots might also be too small. Turn Airscrews OUT more, runs rough, idle goes to crap, then at about 1.5 turns, cuts off. No surprise, figured Pilot was too small, also, just like Mains.
This evening placed 30's for pilots. Almost same indications. Bogs from 0 to 1/8th throttle, right off of idle, really. the warmer it gets, the more pronounced the Bog. If you can "feather" the throttle thru the Bog, it then takes off like, well, a Banshee.
It is now running best and holding best idle at 1/2 turn to 1/4 turn out on the Air screws.
I have 32.5 Pilots, in hand, so, is that the way to go?? Increase from 30 to 32.5s and see what happens to the Bog??
Added info:
-TORS is eliminated, followed all instructions, unplugged all, taped ends all that stuff.
-Has the idle kit and new Carb caps, no problems there, I synch the Carbs each and everytime I replace the caps. Set the idle per what i read, 2 turns Clockwise from where the throttle bodies bottom out and idle screws are just touching them.
-Cut outs facing toward the airbox, float bowls are left/right correct.
-Set float height and check them everytime carb is apart.
-Installed Carb rebuild kits , float needle, seats, Air screws, etc. Fuel is flowing fine, checked that.
-Even in the beginning, first time removing bowls, totally clean, not even any tiny grit.
Only about 300 feet above sea level, 68 to 80 degree temps, 50% humidity.
Running 93 octane at 32:1 ratio
I think I have gone over everything, and just asking, go ahead to 32.5 Pilots and see what happens to the Low End Bog?? If the motor didn't breathe so well, I would think 32.5s were overkill, but, since the bog persists, and turning the Air screws OUT makes it worse, well....that's where I'm at.
any and all thoughts welcomed.
Oh, also, verified needle clip is on 3rd position, so, it's right in the middle.
Thanks for reading and giving it some thought.