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Discussion Starter · #1 ·
I am interested in modifying RC model engines, and want to step up to 125 two-stroke bikes.
The engine I am interested in is a YZ 125 Yamaha motocross engine,
but I want to use all 125-sized forks, wheels, shocks in a steel tube frame,
and running full street gear.
I live in New Zealand. Any ideas on suitable frame etc donors that are not that expensive?
Reasonable forks and brakes are wanted.

In the 1970's, Suzuki used to make a small 125 twin which would be about the right size, but I need something more modern, probably Japanese.
I am 6 foot and 110 kg (240 lbs), so the frame needs to be big enough to suit my size.
1970's 250 and 350 twins seem to be big enough, but the wheels, tires, forks could be downsized a bit.

I don't want a full race fairing and low bars, as I an not that young any more,
and cannot bend into shape that much.

I have some ideas for the Yamaha engine that will pull it up from 33 hp to close to 50 hp.
- see YouTube 2Stroke-stuffing - he has some good ideas.

The resonant inlet power valve seems to be a new one, and would probably work with a slightly modified reed valve engine.
I need to look for a slightly used '20s YZ 125 that is still in running order, and not too expensive.
A complete running motocross bike is around $4500-$8500 nzd
at the moment, ebay US seems to be the only source of separate engines.-
expensive to freight an entire engine.
Any other ideas?
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