engine cuts out at high rpms

[CadillacBanshee]

Happy 4th of july. I've been battleing the jetting on my bike for a LONG time. i get it to run great and then out of no where the engine sputters at high rpms. i have a bad feeling its gonna be more than a jetting issue now, so how do i check the pick up, the cdi, and the ignition. If theres something else i have to check let me know how to check it.

[Ben350]

I fought the same thing on my bike. 1st, 2nd, 3rd seemed OK, but 4th, 5th, and 6th it would sputter at WOT. Went up and down on jetting, ended up rebuilding whole engine and hopping it up, had new bigger carbs, new pipes, still did it. I knew at that point it was electrical. Unfortunately, i have no friends with a banshee, im only one in our group, so i couldnt swap parts. And i also dont have anywhere around my house where i can test and go 4th gear WOT, so im left with testing resistances and throwing parts until the next ride.

 

I ended up changing the stator, flywheel, and coil. Stator was a Ricky Stator 200w. When i sat down and thought about it, the problem started when i put that on. But with replacing the other parts at the same time, i cant say which one fixed it. But it is SO MUCH BETTER. Flawless now. Fought that prob all last year. So, if you have a Ricky Stator, try swapping for your stock one and see what happens. If not, maybe try swapping flywheel and coil. Also for good measure, take close look at Plug caps, wires, GROUNDS{clean them}. I even ran a ground wire from my cylinder head to the frame to be safe. I hope this helps, i know your pain

[Ben350]

also for checking your resistances, look under the Technical Docs page on the home page. Its all there. But if your parts pass the resistance check, doesnt really mean they are good. Part may fail only when under load

[locogato11283]

well you need to totally rule out jetting first. what jetting are you running? have you cleaned your carbs lately making sure no jets are plugged? did you make sure the floats move up and down freely? before you start trying to track down an electrical problem work on the carbs first. also, i have had spark plugs foul out on the top end before. it would run fine until about half or 3/4 throttle then spit and sputter.. pull a plug and see what kinda spark youre getting..

[CadillacBanshee]

i have cleaned up the carbs every time i change the jets. Ive gone from a 470 down to a 400 and the same problem the whole way. The carbs really dont seem to be the problem. About a year ago the flywheel came loose and was hitting the pick up coil and it scraped it down a bit, but that was a year ago. i really dont want to start buying and changing parts. All my mods are in my sig.

[hotrodbanshee]

I had the same problem and come to find out my sparkplug caps/boots were bad. Spent $6.00 on 2 new NGK plug boots and now she runs perfect. Alot of people don't know that plug boots are a wear item. I thought it was jetting too and changed out the jets a hundred times it seemed like and that never worked.

[CadillacBanshee]

I had the same problem and come to find out my sparkplug caps/boots were bad. Spent $6.00 on 2 new NGK plug boots and now she runs perfect. Alot of people don't know that plug boots are a wear item. I thought it was jetting too and changed out the jets a hundred times it seemed like and that never worked.

 

 

 

Where do you buy them? The dealer only sells the whole ignition module. Can i use any plug boot or does it have to be something special?

[CadillacBanshee]

I had the same problem and come to find out my sparkplug caps/boots were bad. Spent $6.00 on 2 new NGK plug boots and now she runs perfect. Alot of people don't know that plug boots are a wear item. I thought it was jetting too and changed out the jets a hundred times it seemed like and that never worked.

 

 

Where do you buy these boots. dealer sells only complete module and they are not sold on ebay.

[Ben350]

Where do you buy these boots. dealer sells only complete module and they are not sold on ebay.

 

 

Vitos performance sells just the boots

[blowit]

Vitos performance sells just the boots

 

 

Did anyone try dropping the plug gap? Banshees are rather weak on spark and many require dropping the gap to around .020. It will act just like jetting is a bit fat and you will chase your tail trying to find it. Plug caps should be tested for resistance. a good cap should be between 3k-6k ohms. Most of the coils being replaced are actually good. A coil failure is rather rare. They are very simple boosting transformers and not much to go wrong.

 

 

Brandon

[locogato11283]

i have cleaned up the carbs every time i change the jets. Ive gone from a 470 down to a 400 and the same problem the whole way. The carbs really dont seem to be the problem. About a year ago the flywheel came loose and was hitting the pick up coil and it scraped it down a bit, but that was a year ago. i really dont want to start buying and changing parts. All my mods are in my sig.

 

 

400 main jets?! thats huge and almost unheard of. are you sure you arent really rich causing the sputter on the top end? ive run up to about 340 mains before but never anywhere near 400..

[_Hex*]

yea man you need to drop them down, 400 is way out there. maybe 340. my stock bike with pipes and coolhead was running that and it was doing fine. do a plug burn, ride the bike on high gear and then kill it, then check your plugs. because the sputtering is deff the jets

[CadillacBanshee]

400's too big? Even with a full drag port? Before i ported i was running 300 on a stock bore. Now i'm at 400 with a drag port and a p6 kit in my bike. What do ou guys think????????

[WALLACE84]

What elevation are you at? Like loco said, I have never heard of a 400 or a 470 myself. And do what Hex said, go down a straight trail or road or whatever, Full throttle, then kill her and check the plugs. A light brown color is what you want