I have a 85 lt250r bike in wich I have installed 87 lt500 motor. The retro fitting went well, But I could not get any of my pipes to fit . I tried triming down my 250 pipe and got ot to fit. But now when I try to run the bike the engine starts fine and runs okay at a very low rpm range, and then when I reach the upper three quarters of the rev range the engine just sputters and has no power. Is the pipe modification causing this? I dont know for sure if the pipe is the problem because I aquired this engine off ebay and never heard it run, before I put it in my bike. Does anyone know of a pipe that will fit this modification ?
Thank you for your time.

 

Congrats on putting together a pretty lethal combination... Power to weight ratio is VERY VERY good!!!

YOu need a pipe that is designed to work for the 500 motor. You could do serious damage to the motor by running what you have (A butchered up 250 pipe that's made to fit)

You need to do some homework here... there were companies back in the late 80's that built pipes for these conversions... they were called hybrids.
I can't remember brand names, but I'm thinking CT made one, among others... I did see a hybrid pipe sell on flea bay not that long ago.

I have a good friend that can hook you up with a custom made pipe, but they aren't cheap ($500 range)... but you might stumble onto something elsewhere if you look hard enough.

You may have other tuning issues with the motor as well... depending on its health.

I would highly recommend that you don't run the 250 pipe, I'd hate to see you burn things down.

 

Thanks for the info. I will not try to work with 250 pipe any more. I belive the engine is in good shape. good comprresion. new reeds, new main and counter shaft bearings, and no gasket leaks. So it has to be the pipe or carb settings. I have orderd a trinity pipe (for a 500) wich I am told will work. but if it dosent I would definitly like some more info on your friend that builds pipes. Does he have a web site?

 

Click on the camera under my name. The last picture is a LT250/500 hybrid pipe. Dr. Q over on macdizzy.com made it for me. Duneaddict's price was in the correct range. CT did make one but I don't know if they still do. Macdizzy's forum costs 12 bucks to join, but Dr. Q's LT500 motor Rx and LT250/500 hybrid Rx threads are worth alot more than that.

 

to talk to Dr.Q just go to planetsand.com and pm him


my motor and pipe are both done by him

 

Don't throw your $$$ away on a trinity pipe!!!! and then chop it up to make it fit...

Save your $$$ and get one of Dr. Q's pipes... Anything else is sub-optimal

 

Thanks for the info. I have made a deal with trinity to return the pipe if it does not fit. So far most of the reserch I have done only turned up pipes that mount outside the frame. Can Dr. Q make a pipe that fits inside the frame.

 

his 250 hybrid pipe is an inframe.



search in the planet sand 2-stroke 4-sale forums for: 250 hybrid pipe.
or by username: Dr.Q



you will be able to find info on his hybrid pipe, he was selling soem about a month ago on there

 

Since nobody read my first post [img]i/expressions/face-icon-small-confused.gif[/img], I repeat..... The pipe in my pics is one of Dr. Q's. It's an in-frame pipe for a built LT500 motor in an 85-86 LT250R frame.

 

Sam, what are you waiting for???? Get that thing put together so you can give us a full report.

Now I can't decide whether I want to chrome my pipe or not... I really like the 'raw' look, but yours looks pretty good.

I'm still waiting on my parts/pipe... The pipe's gunna be a little bigger than yours (Roidzilla transplant) [img]i/expressions/face-icon-small-wink.gif[/img]