[G-forcer]

I made my GPR 50 in to GPR 250. I used YZ250 engine. The bigest problem I have is that to start I have to push and I had some problem fitting the carb, it's very tyte there, because of those bars that hold the shock. Also I am scared riding it, so many people say something going to let go !

 

[G-forcer]

I made my GPR 50 in to GPR 250. I used YZ250 engine. The bigest problem I have is that to start I have to push and I had some problem fitting the carb, it's very tyte there, because of those bars that hold the shock. Also I am scared riding it, so many people say something going to let go !

 

[G-forcer]

Ow yeah ! If I ever had to replace 125 engine with an other 125 it would be CR125 or YZ125, this engines are already racing and willing to take the beating ! More power than that rotax could ever have !

 

[rickyduck]

niiice

 

[banzairx7]

Awesome!

 

[G-forcer]

I gotta question. How come Aprilia and Cagiva got their own galary and we do not ??? Who's in charge here? lol

 

[HutchysRS50]

I gotta question. How come Aprilia and Cagiva got their own galary and we do not ??? Who's in charge here? lol

Wellcome to the derbi section mate... this is a world of its own, noone on here cares for us little people, took us ages and alot of effort just to get the FAQs up.

 

[ectoplasma]

Ow yeah ! If I ever had to replace 125 engine with an other 125 it would be CR125 or YZ125, this engines are already racing and willing to take the beating ! More power than that rotax could ever have !

Hey mate how fast does your 250 go? Have you passed 100 mph without anything breaking ( no offense , I love your bike ) Cause I wanna do the same but with a rd 350 enigine. Found someone who can get it in there for me with some welding and stuff. Thought it might be fun but just curious if the bike can take the beating ? And I assume you still have the gpr 50 frame and not the alluminum bennelli frame of the gpr 125 ?

Can anyone else here tell me if a gpr 125 could take the beating 70 hp would give?

kind regards and thx for all comments so far

Ecto

 

[HutchysRS50]

Make sure you get the frame supports fitted...

And be ready for the front forks to bottom out alot

 

[G-forcer]

Hey mate how fast does your 250 go? Have you passed 100 mph without anything breaking ( no offense , I love your bike ) Cause I wanna do the same but with a rd 350 enigine. Found someone who can get it in there for me with some welding and stuff. Thought it might be fun but just curious if the bike can take the beating ? And I assume you still have the gpr 50 frame and not the alluminum bennelli frame of the gpr 125 ?

Can anyone else here tell me if a gpr 125 could take the beating 70 hp would give?

kind regards and thx for all comments so far

Ecto

Yeah I made a thread about my project with pics and also I'll try answer every thing there!

 

[mattz123]

put simply.

it can be done, but 250cc 2 stroke engines need alot of work to maintain and cost a fortune on re-builds.

you could buy a aprilia rs 250 engine, probly make it fit, but it would involve ALOT of work, new loom, new carbs, new cables, new manifolds, new airbox's (which wont fit so probly need a K&N stype filter, which you know are rubbish) work to the frame, welding points etc..

so yes, it CAN be done, but your either rich or stupid to try it, most people will just buy a 2500cc bike or bigger if they want a faster bike.

but doesnt that defeat the point of upgrading? to take something small/low/sh*te/whatever and make it good? go for it u never know unless u try?

 

[HutchysRS50]

but doesnt that defeat the point of upgrading? to take something small/low/sh*te/whatever and make it good? go for it u never know unless u try?

thats what big bore kits and bigger carbs are for

 

[Greg RS125]

Wellcome to the derbi section mate... this is a world of its own, noone on here cares for us little people, took us ages and alot of effort just to get the FAQs up.

Lulz

 

[1991 Mito MK1 :)]

i really want to put my 83 suzuki rm engine in my mito....

 

[mattz123]

that looks like a monster in a good way. nice as

 

[ectoplasma]

i really want to put my 83 suzuki rm engine in my mito....

well , after learning the hard way I do no recommend engine transplantation...

 

[darkstar]

well , after learning the hard way I do no recommend engine transplantation...

the hard way? what happend with your project Ecto?

 

[tzrman1984]

yeah annit i want to know

 

[Jeram]

Do you actually have the big bore kit? Not to be negative about it, it seems like the right way to go to me 2. I just don t know of anyone who has it and can t wait to hear a review on it . And you are right that is absurd. But a fact is that anand in mito forum has a 88 hp 350 cc mito or something like that so that kinda does own all of us here at derbi forum even people with a full tuned derbi will no way in hell ever even get half of that

from what Ive gathered from the forums, It wouldnt matter if you were on his 350 and he was on your stock derbi, he would probably still own most of the people on the forums...

Im currently building a KTMito380 and I dont recomend doing it unless you have a builder, there are so many things involved that you (and I) would never in a million years concider. I thought of myself as having a decent knowledge of bikes, I can pull apart an inline 4 race engine and put it back together without many dramas etc. but shoehorning an engine in has its dramas.

for example,

-trail bike engines like the one im using have different primary drives (the gear between the crank and clutch), you will need a custom primary drive if you want speed.

-Head and cylinders are designed for dirt bikes (biased towards bottom end power)
and the pipe will go under the engine, and different shape so you will need a custom pipe

-where is the bigger pipe going to go?

-how are you going to make the engine mounts? if billet mounts, whos going to design and make them?

-the new engine, how does it fit in the frame, is the sproket offset? if yes you will have to offset the rear sproket to match etc

-are you upgrading your brakes, forks, and shock to match the power upgrade or do you plan on running into oncomming traffic?

I dont want to discourage you because my build is currently a very very rewarding experience for me (untill the sh#t hits the fan!)

but do your homework and speak to some expert builders first, and lastly dont always beleive everything you read on the forums when it comes to major work like this!