lt250r 4 stroke hybrid ?

[LT250RMan]

Ok, I picked up 2 1988 lt250r's and one of them has no engine. Im looking for some ideas for a 4 stroke hybrid for motocross.

What do you guys think would be a good 4 stroke motor for this build ?

[troybilt]

RM-Z450/250

[LT250RMan]

Originally posted by troybilt
RM-Z450/250

Does any know the height of a rmz450 motor ?? I do not want to hack up the top frame rails to make a motor fit.

[LT250RMan]

I can get a z400 motor reasonably cheap. I might go with the 400 motor just because of the price.

What do you guys think ?

[yfzttracer76]

i would just sell it and buy a better handling quad. I owned an ltr and they are great for what they are. There is a lot better out there for reasonably priced. Just trying to save you some time and headache bt in the end its your choice.

[LT250RMan]

Originally posted by yfzttracer76
i would just sell it and buy a better handling quad. I owned an ltr and they are great for what they are. There is a lot better out there for reasonably priced. Just trying to save you some time and headache bt in the end its your choice.


First of all man, im not asking if I should use a lt250r chassis. My question is, what motor should I put in my spare Lt250r ??
I own 3 quadracers and a 2008 trx450er and I do realize how the quadracers handle. I think it would be cool to own a 1988 quadracer 4 stroke with burgard long travel +2 a-arms and a extended axle.

[NED441SUZ]

I say a RMZ250 with a 280 0r 300 big bore.

[ytman]

I'm a big fan of keeping the same brand engine with the same brand motor.IE: Suzuki with Suzuki. I don't know that a 250 4stroke is that much shorter than a 450. I do know that a 450 can beat up a 250. A smaller displacement engine is a backwards move. Either way an engine swap is not easy and you will be "hacking into " something. Have you considered a 500 2 stroke? That seems like the ultimate choice.(to me) A counterbalanced big bore 2 stroke in that chassis would be the the you know what.

[LT250RMan]

Originally posted by ytman
I'm a big fan of keeping the same brand engine with the same brand motor.IE: Suzuki with Suzuki. I don't know that a 250 4stroke is that much shorter than a 450. I do know that a 450 can beat up a 250. A smaller displacement engine is a backwards move. Either way an engine swap is not easy and you will be "hacking into " something. Have you considered a 500 2 stroke? That seems like the ultimate choice.(to me) A counterbalanced big bore 2 stroke in that chassis would be the the you know what.

Im looking for a good motocross engine and the lt500r motor is to crazy for mx quad. I want to stick with a 4 stroke. Im really leaning towards a z400 with some mods.

[ytman]

I raced a Z with a big bore kit once, in the desert, and I was amazed how the thing kept pulling on top. It's electric start right? You will be modifying the frame' but it should be cool.

[LT250RMan]

The only thing im worried about is how tall the z400 motor is, Im hoping I don't have to modify the top frame rails to much. Ill mod and fab up the motor mounts, swingarm ect. I just don't want to actually cut up the fame to accept the motor if its to tall.

[ytman]

If the swingarm bolt goes thru the motor, that that will dictate wether or not you will be modifying the bottom, top, or both b and t frame rails.

[LT250RMan]

Originally posted by ytman
If the swingarm bolt goes thru the motor, that that will dictate wether or not you will be modifying the bottom, top, or both b and t frame rails.

Im sure I can make the swingarm bolt work with some fabrication to the swingarm or engine bushings.

[ytman]

Good luck sir.

[TRKR]

I thought of doing this conversion myself, just lost the frame to someone else. IMO the quadracer is the 1 of the roomiest frames. A 400/450 engine will fit in there, no problem. It is true that parts are hard to come by, but you know that already.
The 250f engines are really small compared to the 450's. I put a 250f in an ATC 250R and that trike has no space at all. Also, the quadracer is very light and handles well for its age.
I would go with 400 engine. Electric start, very reliable, plenty of aftermarket, can produce very decent power and torque. What's not to like? You may need to check cooling capacity of the quadracers' radiator and its ability to efectively cool the 400,
4 stroke motor. I'm sure other things will pop-up. But hybrid projects are just like that and that is to be espected.
That should be a great project and trail bike. Just my opinion.

TORKER.

[madmaxmodquad]

use a dr based motor from a enduro ive seen the lt230 auto motor on a dr600 frame so the other way should be just as easy i have a dr 600 currently waiting for the a lt frame to stuff it in cutting it is the least of your worries

[headache]

I would at least try to stuff in a rmz450 motor. i have an lt250r and i rode my buddies z400 last weekend and it doesn't have near as much power as the 250. it is stock however. i just think u would be going backwards by using the 400 motor unless u make a 440 and cam it and up the compression

[LT250RMan]

Thanks for the interest but this thread is almost 2 years old. I never finished this quad, I sold it to a friend and now the motor mounts are back to a 250.