1980 rm 125t

[dongabsch]

i have a 1980 rm 125t and i would like to make it more rideable with less of a power band.  can anyone advise me on how i would go about doing this?  any info would be appreciated
thanks donny

[DR]

Simplest method I know to detune a bike is fit a restrictor to the exhaust. This can be done at the exhaust flange by fitting a restrictor plate (like a large washer with a smaller hole) or you could restrict it at the muffler by decreasing the flow via something like a TS185 muffler. Not the best method but it's rare people want less power from a 125. A flywheel weight may make the delivery more 'flattish' but that's also means having a weight fabricated which will cost $. Try the restrictor in the exhaust. Vary the size till you find something you like but it will mean a rejet of the carb more than likely

[brent j]

Just a thought, Does that model RM have a TS equivalent? Sort of like TS125L to TM125L. I used to run a TS ignition, with external rotor, on my TM125. Gave me power for lights and toned it down for enduros.

Also if there is a piston with a longer skirt. Once again TM/TS crossover.

Brent

[TT5 Matt]

a pe175 will have an external rotor for wieght increase and allow you to keep the cdi sparks but Docs elcheapo washer idea will work too


TT5 Matt

[Lozza]

Restrictors in tail pipes is not a good idea to either tone down power or for longevity of an engine unfortunately. Increasing the compression is the best way to get more off pipe performance.Setting the gearing correctly will improve your ride also,but No1 choice will be enroll in a race school and learn how to keep corner speed up and ride the 125 as they are meant to be ridden. 

[evo550]

2nd head or base gasket?

[LWC82PE]

2nd head or base gasket?

exactly what i was thinking! but specifically a thicker head gasket rather than 2

[evo550]

Good advice, a thicker head gasket is always better than two thin one's.
By the way donnyg thicker head gasket will lower compression, thicker base gasket will lower compression and change port timing slightly, although someone cleverer than me will have to explain what changing port timing does.

[oldmxracer]

I used a Moose Intake Spacer on a 93 YZ125 once thaI set up for woods riding. It moved the power down a little in the rpm range. Could be a cheap remedy....