rebrag
07-17-2005, 10:56 AM
I have a savage with nitro star S-25 motor. I ported
and polished this motor 5 months ago and it was running great.
I also run 30% fuel. I've been doing testing of the three speed
for the last 3 1/2 months for shift point adjustments. Lately it
has been starting to run hotter even with the body off. The motor
was sealed with RTV when I reassembled it from porting job.
I decided to replace o-rings in carb. I bought from hpi, A carb o-ring
kit #1450. I replaced all o-rings on and in carb. This did not help
overheating. I had HSN out 5 turns and still hot. I was looking at o-ring
kit and it had every o-ring in kit to replace all 0-rings in the motor.
I removed back plate to replace o-ring on it and reseal. Upon inspection
found one way bearing jammed on starter shaft.
With it wobling around on shaft when running rotostart it
wore out the 0-ring on the inside of back plate. I replaced o-ring inside
of back plate and the one on the outside of back plate, applied RTV
on the outside of back plate and reinstalled back plate. Replaced one way bearing also. My son and I took truck to construction site yesterday
and with body on, runnig O'Donnel 30% and the outside temp at 95 degrees here in NJ and running truck hard temp stayed around 275 degrees.
My 10 year old son and I were very
happy with these results. The truck is his but he can not use it with out me.
Anyway the point of all this is if you are having similar problem with heat
don't forget o-ring inside of back plate. I read many post on this form about
overheating and I didn't see this problem about that o-ring.
Also the three speed is working great.
and polished this motor 5 months ago and it was running great.
I also run 30% fuel. I've been doing testing of the three speed
for the last 3 1/2 months for shift point adjustments. Lately it
has been starting to run hotter even with the body off. The motor
was sealed with RTV when I reassembled it from porting job.
I decided to replace o-rings in carb. I bought from hpi, A carb o-ring
kit #1450. I replaced all o-rings on and in carb. This did not help
overheating. I had HSN out 5 turns and still hot. I was looking at o-ring
kit and it had every o-ring in kit to replace all 0-rings in the motor.
I removed back plate to replace o-ring on it and reseal. Upon inspection
found one way bearing jammed on starter shaft.
With it wobling around on shaft when running rotostart it
wore out the 0-ring on the inside of back plate. I replaced o-ring inside
of back plate and the one on the outside of back plate, applied RTV
on the outside of back plate and reinstalled back plate. Replaced one way bearing also. My son and I took truck to construction site yesterday
and with body on, runnig O'Donnel 30% and the outside temp at 95 degrees here in NJ and running truck hard temp stayed around 275 degrees.
My 10 year old son and I were very
happy with these results. The truck is his but he can not use it with out me.
Anyway the point of all this is if you are having similar problem with heat
don't forget o-ring inside of back plate. I read many post on this form about
overheating and I didn't see this problem about that o-ring.
Also the three speed is working great.