250x

[adamd]

im just kinda wondering has inyone ever put a honda 250x motor in a 3 wheeler frame? i kinda like the idea i know people have put 350x motors in 250x frames. its very hard to come by 350xs around me or atleast i cant find many 4 sale.
and i really liked my 250x i had plus the reverse would be nice for trails. i could proaly come up with a close to roller 350x and a 250x motor would it work?

[Mrs.Mosh]

Yes the 250x Motor was the same size and shape as the 300ex motor. The 250x engine would almost be the better choice to use, IMO. Reverse was easier to use, it basically has the same power as the 300ex, and you wont have to deal with mounting a battery.
A few guys have dropped 300ex motors in 350x chassis with little work at all.
They almost go right in, with only one mount needing re worked. As will the 250x motor.
Our friend runs a 350x with a 300ex engine.

[adamd]

nice i found it so it is a almost direct bolt in besides the rear top motor mount?
i did a search before i posted this but was not thinking 300ex just 250x basicly same motor besides electric start with the ex and i didnt want to deal with batterys and the 250x are alott cheaper to come by for me. also what kinda modification did u do to the motor mount?

also heres a link to his build if inyone else is intrested
http://www.3wheelerworldforums.com/s...ighlight=300ex

[factoryX]

a 250x motor would wiegh about the same as a 350x motor right? also, I thought the 250x/300ex where based off the 250sx?

[adamd]

im perty sure the 250x was based from the 350x? considering there close to the same besides power and oil cooler no? these r both also 4 valve engines a sx is 2 valve and shaft driven.
and thanks for telling me on the spacers i looked guess i missed it in you'r thread.

this will proly be a winter project for me this winter. i like the idea of reverse and easyer to get parts of the 250x. and i would guess the weight to be around 20 ish pounds less just a guess?

[factoryX]

I remember somewhere that the 250x motor came from the 250sx motor, and the 350x motor was more from the xr400 or xr350 or something..idk..

[adamd]

i really just dont see how i mean i dont know alot about engines but i am a decently fast learner and have spent quiet a few hs building 250x motors and had a few sx motors a part and bout the only semularieties are they are both honda and both 250's

the 250x motor is a 4 valve, manuel clutch chain driven bike with a 1 down 4 up trany.

the 250sx is a 2 valve auto clutch, shaft driven bike with a 5 up tranny

the closes to a 250x is a 300ex bassicly the same bike besides e start and few other lil things

the older close bike would be a 350x in my opinion being the motors are very similar they are almost bolt ins in both frames the bigest difrence being the 350x is the bigbore with no reverse and a oil cooler

am i correct on this?

[rdlsz24]

Yeah that sounds right to me. 250sx engine doesn't seem to have much in common with the 250x/300ex engine at all.

Rob

[adamd]

ok i was just confused on why factory x said the 250sx n 250x were close

[Dirtcrasher]

^ nope, there are very few similarities to the 250SX.....

If you find a good 300EX runner for cheap, have at it. But unless they are abundant and CHEAP, you'll find that you'll want the added power from a 350X powerplant.

Brand new crate motors can be had from 600-1000$, thats the best way to go and you can take your time and save up some cash for it; it will be WELL worth the weight and a few hundred bucks more IMO!

[adamd]

the bigest reason im thing about a 250x/350x frame bike is because i want a bit more power than my 200x and i just am not big eough to ride with the power of a 350x were this bike will be rode alot of tight trails. and when ever i want to upgrade i can drop in a 350x motor for more all around power and sell the 250x motor