Is it worth yz125 engine conversion

[igiyf]

i got a DTR 125 was thinking about throwing a yz engine in there.. the dtr engine in its self is alright..the power valve is pinned and its never let me down,i understand a yz engine will need a lot of maintenance as there not made for the roads.. would it even be that much faster? i know a yz is faster the bike is lighter though.. would you bother? think the results are worthy of the effort?

[G]

If I wanted a faster road bike, I'd buy a faster road bike - something like a CRM250 maybe.

If I wanted a faster motocross bike, I'd buy a YZ and stick a plate on it if I had to ride to the track.

[2006 _p1]

i wouldn't bother but its up to you. if you dont mind maintaining the engine i gues it would be alright on the road. you will defiantly need to mess about with the gearing because you wont get much faster topend on a yz 125 engine than you will on a dtr. just quicker acceleration

[igiyf]

yea not worth it.. was going to put a yz tank and plastics on there and with the dt engine get a frame off ebay and build another bike from scratch.. i just like building making things

[prawny1]

If your just after a project, why not build yourself a yz/dtr125-200 hybrid, all you need is a yz with a trashed motor and a cheap tatty dt donor bike (i think you need a wr 200 exhaust as well) as a bonus you will have loads of spares for you dt when the project is over

They are a pretty popular conversion, you don't get the same power as a full mx bike but you will get all the lighting, reliability and tractability of a dual purpose bike with the handling looks and suspension of a proper mxer.

If you use the 125 engines (so long as its still restricted) you may even be able to ride it on l plates although insuring it could be a problem.

The dtr 200 engines are getting hard to come by, but ive followed a few threads on these type of conversion (including kx-kdx conversions) and the 200 engine seems to make for a fantastic greenlaner/enduro bike when fitted to the yz chassis.

More info on here-

https://www.dirtrider.net/forums3/text/topic/97379-1.html

Its mostly about the kx/kdx bikes but there is a yz/dtr-wr bike on there aswell.

[igiyf]

i may look into that-cheers!

[twotakt]

I'm definately considering doing the yz125/dt200 conversion as in the thread in the previously posted link. It's a **** as I turned down a dt200 in full off-road trim (I've no use for a full off road bike as no access to van/trailer) which would've been perfect to nick the motor from.

Is there any particular yz125 (year/model) which is better than the rest i.e. in handling, looks, suspension, brakes etc?

Also do any SM rims relatively straight swap fit to the yz chassis? Or will it be an excel rims laced on original hubs style jobbie?

Ta,
Jack
____________________
R.I.P. Tareree Shiimi, 1985-2008

[prawny1]

Most yz's from about 1996 onwards are meant to handle pretty well but i think the later shaped bike (2001ish onwards) look nicer and have a better suspension.

I wouldn't go for the alloy framed ones, purely for the fact you would need an alloy welder to make the mounts.

[prawny1]

There is a dt230 version available in some markets, It looks like the latest shape 125 and is tuned for more torque and mid range supposed to be as fast in the high revs still due to the extra cc, but i can imagine finding one of those engines is going to be as difficult as the dt200/wr200 motors.

Parts could be a problem to find too come rebuild time, the gearbox and clutch etc are dt 200 but the crank and top end are different

Its a shame you missed that 200, they are pretty good bikes for off roading, no good for rough stuff or jumps but will pull you round the woods all day.

[twotakt]

Alloy welding wouldn't be a problem as my Dad's friend could do that for me for next to nothing cost wise. Do you think the alloy would be that much better in terms of weight/handling etc?

I think I'll go for a dt/sdr200 motor in some sort of late 90s/2000s yz125 chassis.

Thanks for your time,
Jack
____________________
R.I.P. Tareree Shiimi, 1985-2008

[twotakt]

I've recently discovered that Dt200's and there motor's are difficult to get a hold of, therefore I'm now looking into the option of doing the kdx220/200 in a kx125.

I know someone with a 2003 kx125 which has a broken crank case which was a result of a snapped chain. Fingers crossed he'll sell the bike to me
____________________
R.I.P. Tareree Shiimi, 1985-2008

[prawny1]

I suppose the good thing about the kdx/kx bikes is that there is less wiring to mess with because the p.v. are mechanical rather than electric so you can strip the loom to the bare minimum and run a small battery in the air box for the horn, indicators and brake lights.

[2006 _p1]

[stevo as b4]

Yeah definately if i wanted more go in an on-off road 125 2stroke trail bike, then id look for more cc. The DT125R isn't a bad chassis for dual purpose use, but the YZ/WR's are a stronger more off road biased chassis, that would take alot more punishment and also have better suspension with more travel. The YZ/DT200R would be a nice bike, and IMO you need a bit more midrange on a 125 engine for general off road riding, especially if you want to use it on the road as well. The 125 cannot really be geared to suit both uses, wether it's a DT or YZ engine your using.

The KMX/KDX200 engine into a KX125 frame should also be a very good hybrid off roader IMO. I have a KMX200 and although it was not much faster than a tweaked full power 125 version, the midrange makes it a much better bike for most of the time.