[wrennchhands]

I have a 1998 trx450fm s that looses spark around 1200 rpm then starts to fire again when slows to idle. Have replaced stator, trigger coil and cdi. Any help would be greatly appreciated.

 

[Here 2 help]

I hope you meant 12,000 rpm - 1200 is about idle speed

I will presume you have a new spark plug in it?

Connect a test light to the black wire with the white stripe at the CDI box - light should light with the ignition switch on and the kill switch in the run position. Run engine - if the light goes off at the claimed RPM, move the test light to the black wire with the green stripe at the fuse box and re-run the engine - if the light goes off, check the connections at the fuse box.

Let us know what the result is

 

[wrennchhands]

Yes new spark plug. The rev may be closer to 2000 rpm. I installed a spark tester and the spark stops in the hi rev (2000 rpm) and starts to fire again at a low rpm. I checked the black and white with test light at the cdi and checked good. Does light even when it looses spark to plug.

 

[Here 2 help]

OK - that proves your kill switches and power supply are good - just about has to be the coil. That coil (part number 30510-HM7-003 which became part 30510-KJ2-405) was also used on:
1985 Honda ATV ATC200M ALL TERRAIN CYCLE
1985 Honda ATV ATC200S ALL TERRAIN CYCLE
1986 Honda ATV ATC125M ALL TERRAIN CYCLE
1986 Honda ATV ATC200S 'H86 ALL TERRAIN CYCLE
1987 Honda ATV ATC125 ALL TERRAIN CYCLE
1989 Honda ATV FL 400R PILOT
1990 Honda ATV FL 400R PILOT
and other models.

Try to borrow one off a running machine and try it on yours.

 

[wrennchhands]

Tried a coil from 04 trx. It's not the same coil but it's what was handy. Ran much worse.

 

[Here 2 help]

Going to have to try a proper coil

 

[wrennchhands]

Same problem.

Ok got the new Honda coil in today. Still same problem.