pyromaniac
Member
- Jun 25, 2000
- 377
- 0
I have a old designed 250 2-stroke engine('86LT250) that seems to be designed for low'end from top to toe. It pulls good from bottom but where a "normal"(can only refer to my '93cr250) 250 begin to pull and just in a split second rev to peakrpm and throw you away - this engine just continue slow gaining rev and not pulling much more. I want that mid hit and instand jump to peakrpm, i just love it.
I have a few ideas how to get the engine the way i want it.
First off it have a 34mm carb. Then the intake is different from any i have seen, its a round intake hole(36mm) and then only one reed(steel) to the bottom intake holes and nothing to the top intake holes - no idea what affect this have. The reed is mounted inside the cylinder so to get it out i have to take off the cylinder.
It doesnt have a powervalve wich i understand is one of the biggest improvment of the 2-stroke engine. As i understand gives the engine better low'end, nothing this engine lacks but other changes are make to get bottom of the expence of no top'end.
The silencer is 40cm long so its also bottom end possitive. The pipe i dont know but my guiss would be its also designed for low'end. Any way to measure what its tuned for?
So lets go to the mods. Alternative one would be to modify the current engine. I think that would need to include porting, bigger carb, intake mods(?) and shorten the silencer and new pipe. This may end up costing around $500 and i would have a old tech engine running the way i want it.
Alternative two Would be to buy a '86 or newer 250 motocross and take the engine componets from it. It would then have powervalve and normal intake and already be running the way i want it. I saw a '95cr250 for $700 then i can sell the rest of the bike hopefully get back some of the money, maybe $300. The downside with this is that it may need to be mods made to the engine mounts and the pipe needs to be modified, souldnt be too much. The good thing is i can end up with a faster, stronger and more reliable engine. In the long run i will also save money on cheaper parts for it than the old LT engine.
Alternative three would be to buy only a engine, pipe and carb. Should be cheaper than buying a complete bike but the downside is its hard to know if it works and even harder to know if it run good.
I would like to hear what you would do.
I have a few ideas how to get the engine the way i want it.
First off it have a 34mm carb. Then the intake is different from any i have seen, its a round intake hole(36mm) and then only one reed(steel) to the bottom intake holes and nothing to the top intake holes - no idea what affect this have. The reed is mounted inside the cylinder so to get it out i have to take off the cylinder.
It doesnt have a powervalve wich i understand is one of the biggest improvment of the 2-stroke engine. As i understand gives the engine better low'end, nothing this engine lacks but other changes are make to get bottom of the expence of no top'end.
The silencer is 40cm long so its also bottom end possitive. The pipe i dont know but my guiss would be its also designed for low'end. Any way to measure what its tuned for?
So lets go to the mods. Alternative one would be to modify the current engine. I think that would need to include porting, bigger carb, intake mods(?) and shorten the silencer and new pipe. This may end up costing around $500 and i would have a old tech engine running the way i want it.
Alternative two Would be to buy a '86 or newer 250 motocross and take the engine componets from it. It would then have powervalve and normal intake and already be running the way i want it. I saw a '95cr250 for $700 then i can sell the rest of the bike hopefully get back some of the money, maybe $300. The downside with this is that it may need to be mods made to the engine mounts and the pipe needs to be modified, souldnt be too much. The good thing is i can end up with a faster, stronger and more reliable engine. In the long run i will also save money on cheaper parts for it than the old LT engine.
Alternative three would be to buy only a engine, pipe and carb. Should be cheaper than buying a complete bike but the downside is its hard to know if it works and even harder to know if it run good.
I would like to hear what you would do.