RM125A/B 4 Stroke

[Stewy138]

Hey I was wondering if there an 'easy' (relatively) 4 stroke engine conversion/implant for an RM125A/B ?

Cheers,
Stewy.

[mainline]

are you nuts? some sort of bike-wrecking heathen? how can you even think such a thing?

[Stewy138]

That bloody old song...to dream the impossible dream... is playing inside my head. 

Of course it would be a lot easier to just go original  , if only I could find an engine  ....but where the fun and frustration in that hey  ?

[cyclegod]

XL185/XR200 fits in there I've seen afew in NZ.

[Marc.com]

Hey I was wondering if there an 'easy' (relatively) 4 stroke engine conversion/implant for an RM125A/B ?
Cheers,
Stewy.

Good for you mate, nothing like a good 4 stroke special, though there is an easier path..... grab a DR400 and RM C bits like the swingarm and do your self a DRM400 special. BTW TT500 engine fits RM frame but needs a lot of hacking about. Works better with RM400 N or T frame.

[Tahitian_Red]

Will the DR motor fit in the RM N&T frames?

[Marc.com]

Will the DR motor fit in the RM N&T frames?

Realistically it is too tall, easiest option  is direct bolt up of RM suspension to DR frame. RM250C swingarm goes straight on, N/T forks. The DR400T or S was good enough starting point that frame swap is pointless.

[cyclegod]

Buy this instead...

http://www.ebay.com.au/itm/TT-500-SPECIAL-/380347204677?pt=AU_Motorcycles&hash=item588e75c445

[Stankflapper]

Could someone point out the advantage of doing this?

[Marc.com]

Could someone point out the advantage of doing this?

Should be lighter and better suspended than the original TT frame which wouldn't take too much. Like I said earlier and you can see from the RM370 carve up, TT motor into RM ABC frame requires major surgery and there are better frames for the job, like a Husky one.... 4 stroke specials have been there as long as MX has been there, in fact really scrambles, MX started out as 4 stroke special racing.

[Slakewell]

I going to do an XR 200 special as my next big project , you may not be at the front on one but you will be smiling 

[Marc.com]

I going to do an XR 200 special as my next big project , you may not be at the front on one but you will be smiling 

They were good little bikes in their own right and popular in their day, any thoughts on frame, CR125 comes to mind. OR keep the original frame as there was not much of it anyway and do something with the suspension.... heres one I did with $100 XL250 wreck

[Colin Jay]

Could someone point out the advantage of doing this?

Should be lighter and better suspended than the original TT frame which wouldn't take too much. Like I said earlier and you can see from the RM370 carve up, TT motor into RM ABC frame requires major surgery and there are better frames for the job, like a Husky one....

The only / slightly difficult part is making an oil tank.

CJ

[Nathan S]

There was a KLX powered RM125C(?) at CD6. Pretty bike, apparently went well with 310cc kit in it.
Its been mentioned before on these forums, I think the owner even popped up.
Dunno what it achieves compared to a mildly modified KLX as a race bike, but a modded KL engine in an RM-B frame could have potential as a pre-78 race bike.

[Davey Crocket]

Hey MarC....maybe you should have spent $200 and got a front end for it......looks a bit hard to ride with one wheel and no handlebars.....