EvilBanshee

No i havent checked it. That will be my next step. I ordered a New Coil and wires. And Plug Caps. i put the coil on. Did the same thing. Waiting for my caps to come in.... Its Weird. One time the bike will sounds perfect and Fly! and next minutes it will Sound like its reving. But it wont be making any power? I think it sometimes just runs on 1 cyclinder.

Im still a believer using 1st gear on Grass Iv Never lost a hole shot even.

Usually its rich when it wont rev out on WOT. Lean it will rev like hell and ping and pop. Drop 2 Mains and if it fixes the problem pull the plugs and see its its burning nice(Light Brown), lean or still a tad to rich.

Mine is doing the exact same thing!!! its pissing me off. I just put together a Vito;s 421 and iv been chasing it. Sometimes its fine. Other times its runing like on 1 cyclinder

Its hard for us to tell you. You need to try it yourself and then tell us what its doing. Then we can help you. Make sure you start as rich as you can ,and work your way down.

Drop to main jet sizes and go!!!

Clearly its a joke..?? Canada has lots of snow.... Man no humour around here. And it was suppose to say "In 4 feet of snow" my bad..

I would stick with the NGK BR8Es as well. Nothing against Campion... NGK is a good plug thats proven.

What do you wanna know??

Hey lets see you try and launch a banshee is 4 feet of snow and get it to hook. It takes serious skill

Maby you just havent Raced anyone That can ride...

Actually thats a good idea, I just may try that. And yes i have a temp gun, The Right side does run cooler.

No it cant be tranny fluid. The level isnt going down. And i would see it and smell it burning i would think. I shouldnt say it waay richer. Its just richer. Im gunna pull off the carbs and give them a good cleaning. Becasue sometimes all of a sudden it will have all its power again and it will pull hard. But then right after it will start running like crap. It s weird....

Do any of you guys have to run staggered jetting?? I have 34mm Keihln's on my 421. 168 mains. 40 pilot. The left side is a tad rich which is the way i want it. But the left side is waay rich, to the point it runs like garbage. Iv swapped wires and everything. What could be the problem??

I always start in first on grass. I have a Stock swinger as well. Never had a issue. Pavement I start in second and Ride the Clutch out. Mud i start in second and dump it. 90% of the time im on grass dragging. Im yet to loose around my neck of the woods If i were you id start in first and play with the throttle until you get her rolling then grab second. Alot of guys i race just spin and not move anywhere due to over powering the terrain, By the time they get traction i have 25 feet on them and the race is alll over..

Up your pilot jet 2 sizes. and play with your idol screws. See what happens.

If you happen to go with this set up. Deffinity go as big as you can. But i would personally stick with a 34 or 35mm double carb set up.

Just wondering if theirs a better Ignition Coil and wire set out their. Mine is the original Ignition Coil with Original wires. Their loose fitting and rattle on the spark plugs. I was just curious if their is a better brand out their then a Yamaha Stock one??

Are you using a different fuel then before???

Poor English!!!

Thats good advice!

Same thing happened to my 421. What happens is that when you let off the throttle at hiiigh RPM's you starv your motor for fuel/oil. and on a fresh engine, it will lock up fast ! I checked out my engine after it happened and it was ok. Just a tiny bit of metal transfer. But let me tell you its a scary feeling after you spend almost 2 grand on a new powertrain and it lock up on you. But all is good still

Hey man, welcome. My Advice is to start tearing her apart, and make it bigger and better! welcome to the banshee life!!

ya my old engine, was a 404 with a stock head, and 28mm Carbs. I destroyed a 05 YZF 450, and it had a 13.5:1 piston in it with e FMF Muffler. And that same race their was my buddies ported 350 banshee, and a 700 rapter. Both banshee demolished. 2 stroke all the way!!!

Pull the carbs and give them a cleanin.