got no idea how to do any of it but dooo it show the mito boys we can go just as fast

 

if you have to ask your not capable really tbh

 

Well no I m not capable ... Like most of us here. That's the whole point of the forum no ? To help people who are clueless and incapable to become capable and well informed? And I never said I'd actually do it I'm just curious to see if other people here think it is possible. And if they do believe it is possible I might do it and try andto do most of it myself with the help of you guys and the mito 250 guy from somewhere around here, my dad and maybe a mechanic for some things.

But right now this topic is just theoretical and I want to motivate people to think about this and maybe consider it.

Like flackie 666 said "got no idea how to do any of it but dooo it show the mito boys we can go just as fast

"

we dont just wanna get owned by the mitos guys now do we ?

 

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.

 

I hope i m not stupid and unfortunately I m not to rich either. But in belgium you need to be 21 in order to ride a 25 kw + so that excludes most 250 2 stroke racers and onwards ( unless they have different papers ) . Besides I m quite fond of the looks of my gpr and would hate to have to replace it. There are a lot of second hand engines from damaged , old or tuned bikes out there for very little money , even second hand cross bikes which are just real old and outdated and therefore cheap but often have done very few miles... So that s why I m considering this, or at least finding it worthy to discuss on this forum. I bloody well know that it s far easier to just by an rs 250... And if I were rich and there were no laws I would be riding a turbo injected suzuki hayabusa 1300 but i'm not ey...

 

This is reposted from the other thread just so the info is in the right place-

A Yamaha WR200 engine will bolt up to the sub frame. It uses the same cases as our 125 motor. Im not sure if the head clears everything though. Also unsure if the 125 exhaust will mate to the 200 motor.

 

Seems to me that it is better and cheaper to just get the 170 cc kit like you are doing then as it is only a 30 cc difference and at least you can still fit a race exhaust to it

 

Interesting.... just after I bought my bike the 250cc disappeared from the Piaggio site. I have never ever seen one, but they apparently did exist in some markets somewhere !

Before my local Piaggio dealer shut up shop we spoke about this and he said it was a version of the Aprillia 250 they used. The GPR was (apparently) designed as a 250 (hence the "chunky" feel).

Personally speaking the best bike for this kind of tampering is the 1st generation Hyosung GTR's which were available in 3 flavours 125, 250 and 650. The engine used is the Suzi SV Vee-Twin, torquey and reliable also rather tuneable with being all out yeeha !

The mito boys do it because Cagiva have a ready supply of evily tempered larger 2 stroke engines which they can drop straight in... however if you read that thread you'll see they have brutal issues with sprung weight on the front forks causing them to bottom out in rather spectacular fashion !

 

Their are no engines that drop straight in the mito chassis, just happens that alot of people have custom modified mounts to fit in the RD350 YPVS engine, then they have to alter the wiring system, set the carbs up to run on pod filters as theirs no room for an airbox and have a custom exhaust system made up.

 

I think I see where this is going. It is possible but will cost me more to do then I actually paid for my second hand derbi so basicly it s pointless... right?

And I v read a part of the mito stuff and those guys do go through a bit of sh*t to actually get the bike stable and getting everything right.

So are we all agreeing that this would indeed be pointless and more expensive then actually buying a second hand 250 cc or 600 cc bike?

I hope someone will contradict me here cause i d still love to see a 350 derbi or something simualar.

A 200 or 150 engine seems rather pointless aswell. Even if it were cheap I d only consider it if my engine broke down because, as we all know and as banzair is testing for us, you can get the derbi gpr to 170 cc with the standard engine and a normal 125 gpr race exhaust, so why bother ey... ?

If somemone knows where to find engines that are plug and play ( like a 250 derbi engine or hyosung ) which we can still find today ( I dont think a derbi or hyousung 250 engine will be easy to find though but by all means proove me wrong here) please let us know.

 

Why bother to put a bigger motor that will cause more troubles, just get the big bore kit, a decent exhaust, a big ass carb and sort the sprockets and off U go, dont think u need more

 

No offense taken. Dave and myself have a very different view on these bikes as compared to you guys on the other side of the pond. These are "toys" to us. They are very rare beasts over here, I think there are less 20 in all of the USA. We don't ride them because we are limited by power or CC's on what we can ride. Because of that, to me anyway, I don't mind dumping money into it for a bit more power. For you guys it just makes sense to just buy a bigger bike down the road.

 

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 !

 

 

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

 

niiice

 

Awesome!

 

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.

 

Make sure you get the frame supports fitted...

And be ready for the front forks to bottom out alot

 

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...

 

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

 

yeah annit i want to know