pain in the butt problem

[heath720]

ok i have a 300ex with everything done to the motor. it runs great when i start it up and run it for a while but when it gets hot it starts missing horribly. im sure its electrical but im not sure wat it is and electrical stuff is expensive and i dont have the money to buy stuff and not have it be rite. before i start buying stuff i just wanted to no if anyone else has had this problem and could tell me wat to do. thanks a lot for ur help.

[02440exkid]

could be some thing with the carb. did this just hapen out of the blue?

[bwamos]

Define missing....

Is it not firing randomly at all rpms, under all loads, or no load?

Ir is it missing/bogging under heavy load af full throttle?

If you're running 11:1 with an agressive cam, you may be just a tad lean, causing extra heat, making it easier for the mixture to detonate.

Or, you'r cam timing could be off, could be a plug misfiring under high heat, could be a rich condition even causing your motor to load up, etc....

If could be many many things.

Help us out by describing the details of your missing condition.

[nickmelll]

do u have a tether switch. my cusin has one on his ltr and it started missing bad and we think thats the prob.

[heath720]

well it starts up and runs awsome for about 10-15 minutes then all of a sudden its like someone turned the choke on and there is just nothing there. i pulled the plug and it is a nice tan color like it should be so i dont think jetting is the problem. i am running a 400ex carb and i have the choke taken off for better air flow so i dont think its that. i do have a tether but i already went through and checked all the wires and they are good. thanks for your help guys.

[Tri-valleyracin]

pull the carb off and clean the jets. mine was doin the same thing and it was a peace of drit that cloged my main jet.

[heath720]

i will try it and let you no. thanks