Rev limiter/governer on TTR90

[NuebieN]

I bought a 06 TTR90 for my girlfriend's kid. She won't let him ride it until I am able to reduce the power of the bike so he can learn without getting hurt. I have been searching and can't seem to find any way to do it.

If you know of a way to limit the throttle on this bike, please post. Thank you.

Jeff

 

[Vic]

You can cut a small piece of PVC tubing and put it over the cable between the slide and the top of the carb to limit the travel of the slide.

 

[NuebieN]

Thank you. I did find someone saying that from a google search. I just tried it. It does keep it from giving it full throttle. The bike still goes pretty fast and I did stick the longest pipe I could get in there and still be able to get the cable in the gap.

I read that yamaha puts a washer in the exhaust to reduce airflow. That seems like it would be better. That way I could reduce it down to idle if I perfer. Do you happen to know where to put this washer? Is it right after the head where the exhaust pipe bolts on?

 

[Vic]

Do you happen to know where to put this washer? Is it right after the head where the exhaust pipe bolts on?

That's where they put it, but I think it's only done on the small two-stroke bikes. I'd be leary about doing it to a four-stroke. The potential for excessive heat causing valve problems is too great. I think making some kind of restrictor for the intake side would be safer.

You might also be able to drill and tap the throttle control housing to accept a limiting screw that would limit how far the grip could be twisted.

 

[NuebieN]

You might also be able to drill and tap the throttle control housing to accept a limiting screw that would limit how far the grip could be twisted.

That's an interesting idea. I'll take the throttle apart and see if it can be done.

 

[NuebieN]

Works a treat. Perfect. Now to find a helmet for him. Thank you for your help.

 

[Vic]

Glad it worked out for you. :cool: