250x/350x Project

[Preddy05]

Alright guys I Should be gettin a 250x. Friend of my dads paid $200 for a 1991 250x. The motor needs redone. Has Original plastic and a white brothers pipe on it. Im gonna offer him $500 for it and if i get it I wanted to know how hard it would be to put a 350x motor in it. I know were i can get 2 bottom ends and an after market cam for the 350x cheap so i'll just need the topend might even have that to gotta talk to my grandpa. Let me know if you have any info on this. I'll post up some pics of the quad tomm.

[350xsx]

i have a complete 350X motor, carb, oil cooler, cobra and stock pipe etc that ill sell ya, im tryin to get rid of it, its on a shifter kart right now, and im puttin the whole thing on egay soon, so iif our interested in it ill get pictures for ya, you can get alll the mounts, a pipe for the converion and all that stuff from Powroll, i believe the sites just at powroll.com
Kyle
P.S. if he wants $20 for the quad why give him another $300???

[Preddy05]

Well i got the 250x! And took the motor out of it and have all the plastic off of it so i can start to clean it up before i go any farther. Heres what i wanna do
*Racing cam
*Heavy Duty Balve Springs
*bore kit but not sure how reliable they are
*Pipe (not sure about yet)
*K&n

Ok well here are some pictures of it....the topend of the 250x is junk. So i might sell the bottom end on ebay or something.


Anyone have any ideas on were the best place for the oil cooler to go is?
Any other ideas of what i should do?

[OldSchoolin86]

Well i got the 250x! And took the motor out of it and have all the plastic off of it so i can start to clean it up before i go any farther. Heres what i wanna do
*Racing cam
*Heavy Duty Balve Springs
*bore kit but not sure how reliable they are
*Pipe (not sure about yet)
*K&n

Ok well here are some pictures of it....the topend of the 250x is junk. So i might sell the bottom end on ebay or something.


Anyone have any ideas on were the best place for the oil cooler to go is?
Any other ideas of what i should do?
I would seriously weigh out the cost of rebuilding compared to dropping in a 350x engine. IT makes one hell of a fun combo and it takes a lot of work to get a 250x up to 350x power. Good luck on the project and the 80mm big bore is a pretty reliable deal in my experience if you choose to go that way. Also the head on the 250x is super restricted so figure on porting too if you want any of the other stuff to work good.

[Preddy05]

I would seriously weigh out the cost of rebuilding compared to dropping in a 350x engine. IT makes one hell of a fun combo and it takes a lot of work to get a 250x up to 350x power. Good luck on the project and the 80mm big bore is a pretty reliable deal in my experience if you choose to go that way. Also the head on the 250x is super restricted so figure on porting too if you want any of the other stuff to work good.

I plan on dropping a 350x engine into it but i don't wanna drop a stock 350x engine into it so the list that i put up is what i would like to do to the engine.
I should get a price on the engine i wanna get this weekend. Maybe i'll get it ported as well.

[Preddy05]

I was thinkin about puttin a 400ex carb on it when i start to get everything togeather. I heard you have to open the intake port if you are gonna use a 400ex carb. Will it make it run alot better with a 400ex carb or should i just use the 250x carb?

Thanks
Mike

[Mike_Ham_250R]

http://powroll.com

[Mike_Ham_250R]

Powroll has a kit for this including Supertrapp exhaust.

[Mike_Ham_250R]

Kinda expensive though, I was looking here (http://www.powroll.com/P_HONDA_CONVERSIONKIT.htm) and maybe it would be much cheaper to make the 350x/400ex exhaust fit and spending only $70 on the mounting hardware rather than dropping $470 on an exhaust with the package.

[Preddy05]

Its been awhile so i figured i would let everyone know whats goin on. i'll get some pictures tomm. of the roller cleaned up and the parts i have for it.

What i got so far.
-Complete 85 350x bottom end w/cylinder, oil cooler, head cap, and cam (not stock its biger) $250
-Powroll Conversion head pipe $117, im gonna use it with the white brothers silencer i have for the 250x
-Powroll spacers w/wiring instructions $82 (should get them on the 6th)
-Rear Bearings and seals $21
-Head & cylinder $225 (just won today so who knows when i will get it)

Still need to get alot of parts (14t front, 38t Rear, chain, swingarm skidplate, kick leaver, stronger valve springs, piston, rings, topend gaskit kit) Those are just some of the things off the top of my head. After i get the spacers im gonna grind the motor to make it fit (the back tube where the motor mout bolt goes through. was told have to grind it to make it fit.) Then after thats done im gonna see how far the oil cooler will reach to see were i wanna mount it. I should have most of the parts i need ordered by next week.

If you have any Ideas on what else i should do let me know

Thanks
Mike

[Preddy05]

Heres some pictures of it and the stuff...i'll post a couple more.

[Preddy05]

sorry the pictures arn't that great...would of got better ones but there is to many bikes in their to move anything around. im not sure what tires and rims im gonna use yet because the ones i pictured i might put on my predator.

[Mosh]

the oil cooler will mount up near the cdi box on the front 2 down tubes of the frame.basically the same place that you would find it on the 350x.i would strongly recomend port and polish.it will make the engine rev like a newer 4 stroke and really,you will get fullpotential from the cam that way.a 250x carb will be way too small.stick with a 350x carb or you can go with the 400 carb.but a 350x carb will go right in there.you will also want to get a 350x harness and cdi box.i believe the 350x cdi has different timing advance and rpm limit on it.the 250x cdi might end up choking the 350x motor performance.but i rode one last year,and you will love it.i would also recomend putting 400ex arms on the front.then you can modify stock banshee shocks to fit the upper frame mounts.that willwiden it out to 400ex front width and give you 2 inches more travel.i did the 400ex front end on my 250x and i love it.still looking for a good doner 350x engine for it though.

[Preddy05]

Thanks for the info! always nice to hear from someone else. I do wanna get the motor p&p but i don't know anyone around here that does it. Still not sure if i wanna spend lots of money on the motor or not because im not sure if im gonna keep it or sale it. Really have no need for it bein i have a predator and my dad has a 350x and i might have to put this project on hold because i might be buyin a 91 rm 250 for $500 .

[SWIGIN]

when i built my 250x/350x quad i used a 250r rear shock...not as hard as it sounds to get it in there you just need to be able to weld the linkage mounts to the frame and build a new swing arm. i also used 250r long travel front shocks too but you have to cut the old upper shock mounts off and build a new one higher up on the frame

[toyota200x]

Awesome build. Keep us updated,

[Preddy05]

Well i got the Spacers with instructions. And i got the head and cylinder so bein i won't have anything to do this weekend....maybe i'll start workin on it!

[Preddy05]

Today i cut the motor so it would fit and installed the bottom end. Im gonna put the oil cooler near were it is on the 350x. now that the bottom end fit i gotta take it back out because you have to have the motor togeather before you put it in. cylinder is just little to big to fit on. here are some pictures of it.

Should have front and rear sprocket and topend gaskit kit in a few days.

[Preddy05]

Just got a few more parts.

Piston Pin $16.64
Ex. and In. Rocker arms $91.80
Front sprocket $18.36
Back Sprocket $34.36

Still waiting for the gaskit kit because when i went to get it a couple days ago they ordered me the wrong one. If i don't find a stock cam by Friday im gonna buy the race cam and valve spring kit off the powroll site.

some pictures of parts i got and peice i had to cut off bottom end to make it fit.

[Preddy05]

thought i would post up some pictures of what it looks like with the motor in it. got it wired up last night so i put the gas tank on it and it fired right up! Now i have to build a bracket for the pipe and one for the oil cooler and i'll be able to ride it. I think later down the road if i keep it i'll put a differant oil cooler on it something a little bigger to help it cool down better. Should have it done by tonight if im lucky.

[Mike_Ham_250R]

Looking good man! Hope to see you at the races!

[Preddy05]

I would love to go to the races but i have a problem now! Got the bike back togeather and was riding it to see how it rode and rode it for like an 30-40mins and relized the oil cooler wasn't gettin hot....took off the side case and the oil pump was broke! so took out the oil pump from the 250x and made it fit. now its gettin oil but but it smokes really bad! Now im goin to take it back apart get the spare cylinder i have bored out and get new pistin and rings for it. But after i get it togeather i do want to come out there and race. and im goin to have to gear it down some. Im not sure if its because its not running right or if the 14/38 gearing is to high but its not what i thought it would be! i'll post some pictures of it tomw of it togeather after i get back from riding.

[travis712]

You think you fried up the rings or what? Well I hope you get it all back together in working order.

[Xowner]

hope that it is only the rings and piston most of the time its the head that sees most of the damaged