03 TM85 Overrev problem

Joined
Jul 7, 2003
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#1
My son's TM85 does not seem to want to overrev like it is staving for gas, (starts popping at a certain RPM range.) have tried to go to a larger main jet (210) but it did not help, just blacken the spark plug and run fat. The bike came with a 200 main which also was a little fat. Using a (195) main and plug is a good color of tan. I think this bike has a revlimiter and is there a way to disconnect or remap the ignition? I think the iginition system is a Kokusan. I have even narrowed the plug gap which did not help. Can anyone help me with a answer other than going to a japanese bike?
 

MikeS

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Joined
Jun 12, 2000
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#2
By chance did you check the reeds.
Our TM125 had cracked reeds for the longest time as it would pop and not rev out.

Also we went to a B8EG with the stock (fatter) main. For some reason we developed a condition that caused the bike not to clear out when running slower sections or trail riding. The hotter plug did the trick.

Another time we had a popping and that came from a bad ground at the coil.

Just a few thing that may help.

These ignitions are used for karts that rev way out 12-14000. Not sure if the 85 only has a limiter.

http://greenflag.net
These guys do karts but are helpful for the bikes
 
Joined
Nov 14, 2000
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#3
There's no limiter my '01 TM85 Rev's big time which is virtually the same as the '03 other than some plastics motors are identical.