What causes high RPM misfire or sputter ?

[Jayraye39]

like ive said its been running strong for 2 years. dont know why it would be bad now and only at a high rpm. just a wierd situation this one is

 

[GW's Motorized]

like ive said its been running strong for 2 years. dont know why it would be bad now and only at a high rpm. just a wierd situation this one is

Magnets can demagnetize ofer time

 

[Wrench]

It is part of the ignition system and you have replaced everything else, Might as well replace the Mag to eliminate it as a problem

Sometimes parts swapping is the best troubleshooting for ignition systens

 

[Jayraye39]

replaced the magnet and the entire electrical system. Im going back to the carb. This NT carb is junk. If the new carb dont fix it im done. Gonna trash the motor for spare parts and order a phantom

 

[GW's Motorized]

replaced the magnet and the entire electrical system. Im going back to the carb. This NT carb is junk. If the new carb dont fix it im done. Gonna trash the motor for spare parts and order a phantom

I wonder if maybe you are having fuel delivery problems. You said it cleared up a bit when you put the gasket on the right way, maybe that was just your problem to begin with.

 

[Jayraye39]

yeah Ill just toss it if it dont work with the new carb. already rebuilt the entire electrical system. If im gonn put my time ino something might as well be worth my time like the phantom. plus this motors had it fun. jug is 2 yearz old and case is 4. Might just throw it back on boardtracker #1 when P85 gets here

 

[Jayraye39]

So here is a question. When I changed my plug lead wire i noticed one of my cooling vents got moved over a bit. Its kinda close to the plug it self. I didnt think nothing of it because its got a rubber boot on it. But im wondering since high rpm spark happens way more rapidly. That maybe some of thoes charges could be jumping off over to the cooling vent. the closes part is down twards the bottom of the porceline on the plug and its less than 10mm away. Could this be my problem? its the very last thing in the electrical system that could be faulty

 

[Jayraye39]

I can detach the vents in under 5 min. I should do a pull without them and see what happens. just wish i had a way to test if its jumping

 

[GW's Motorized]

I think its worth a shot. Ive gotten shocked through a plug boot before on my mini bike.

 

[Wrench]

Funny story,
Once I put the old fashion thumb screw lead on my S/P because it looked Old Skool Vintage
The first day I got shocked when I touched it by accident I put the S/P clip on lead & rubber boot back on