cr250/400ex questions?

[Zakradu398]

I think I really want to put a cr250r in my 400ex. Does anyone have tips on what all I will need and if the pipe and sprockets and hard to line up? Thanks.

[Langbolt]

http://www.servicehonda.com/honda-2010-models/atv-srx250r

Service HONDA has all the parts you need!

:devil:

[Zakradu398]

Do you know what it costs there for the parts . I'd look but I'm on my phone driving lol

[jcs003]

I [ut a trx250r engine in a 400ex. look up my thread.

[Zakradu398]

Originally posted by jcs003
I [ut a trx250r engine in a 400ex. look up my thread.

250r motor is expensive...

[JOHNDOE83]

I have a cr250/400ex hybrid

It was relatively easy to build and I could walk you through it and send you many pics if you need. I could even send you templates if you needed it.

I used a 98 cr250 that I bought running for $600, The pipe I custom fabbed from a 250r bigbore motor.

I hand made the motor mounts and a used a 400ex swingarm spacer that I had turned down to fit inside the cr250 crankcase.

it sounds like alot of work but it really wasnt for me.

NO frame mods are needed at all!!! all 400ex plastics, gas tank etc, work.

Best thing is to buy a complete running bike, I shopped for 6 months before I found one for the right price.

Just ask or pm me if ou decide to do it! you can even learn from my mistakes and improve where I fell short :devil:

[Langbolt]

Johndoe83 - Please post up some pics....I'm sure everyone on here would love to see how you put it all together.

:D

[Zakradu398]

Originally posted by JOHNDOE83
I have a cr250/400ex hybrid

It was relatively easy to build and I could walk you through it and send you many pics if you need. I could even send you templates if you needed it.

I used a 98 cr250 that I bought running for $600, The pipe I custom fabbed from a 250r bigbore motor.

I hand made the motor mounts and a used a 400ex swingarm spacer that I had turned down to fit inside the cr250 crankcase.

it sounds like alot of work but it really wasnt for me.

NO frame mods are needed at all!!! all 400ex plastics, gas tank etc, work.

Best thing is to buy a complete running bike, I shopped for 6 months before I found one for the right price.

Just ask or pm me if ou decide to do it! you can even learn from my mistakes and improve where I fell short :devil:

For sure want to do this. The ole hundy just isn't fast enough lol. What kind of budget should I have for this? Not including motor.

[JOHNDOE83]

well heres a basic parts list to use as a basic research guideline for pricing.

This is without motor, I bought a complete bike for $600. Even if you bought a higher quality bike for $1000 you will still be ahead of the game.

Most of this stuff you already have 1 set of if you have a 400ex and cr250.

around $50 in steel from lowes and home depot.

2 sets of 400ex motor mounts and bolts.

2- cr250 kickstart knuckles.

2 sets of 400ex swingarm spacer/bushings.

some type of radiator, mine was $40 and it went to a late 80s cr80r. I also have a cr125 radiator thats a lil bigger im gonna use in a future build, you might be able to make the cr250 rad work.

around $50 in misc bolts, spacers, washers "maybe".

you will need to custom fab a pipe, I recommend using a 250r pipe because it already almost fits a 400ex frame exact. to make mine fit I used the cr250 pipe flange that inserts into the motor and cut the FTZ pipe at the right angle to work for my build.

You could find a new pipe for $200 or buy used for less money.

Long story short, I routed my pipe differently then the 250r, this made the stock cr250 rad not fit which to me didnt matter . I was using smaller and lighter anyway for drag racing purposes. This is also why in my pics the pipe sits LOW in the back instead of up high. If I routed it the correct way and wasnt using such a fat pipe, it would have routed normally.

You need the extra swinger spacer, you trim it down to fit inside the cr250 crankcase because the cr250 swinger bolt is slightly bigger, a machine shop turned mine for $40, I then cut it to 3.5in and it fits perfect in the cr250 motor.

After the swinger spacer is done you can fab mounts, start at the front then top then bottom. I bought? I believe it was 3/16 flat plate steel, 3/16- 1in flat bar, 1in square tubing, 1x1 angle metal.

I custom fabbed everything and test fit 100 times, marked everything for exact fits with line marks etc... then took it to a welder.

There is also a RM250 hybrid in here that built his the same time i built mine, you should look up his thread.

Heres links to my before "mock up build" and my after "revised" build. I decided not to go into detail about the revised mods but will gladly share them if you are going into this build.

I will also get you detailed pics of the mounts this weekend.


Before, mockup build. http://www.exriders.com/vbb/showthread.php?s=&threadid=477981&highlight=hybrid


After, with revised mounts ETC...

http://www.exriders.com/vbb/showthread.php?s=&threadid=498018&highlight=hybrid

[JOHNDOE83]

heres some of the motor mount pics, the only one I didnt get a pic of was the mount for the top, not sure if it even needs that one but im going to use it anyway for safety issues. The mount is already made I just have to weld some wings on it for support.

This front mount is supported by the stock 400ex front mount location, the spacers are made from the top motor mount from a 400ex and the bolt is also the top mount bolt for a 400ex. If you look closely you will see the only frame mod I had to do was cut the stock 400ex front mount nuts that are welded on, the vibration rattled the welds loose on the nuts, I recommend cutting them off and using reg nuts.


front mount
http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00213_zpsbe2cef79.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00214_zps43bcdbe4.jpg



bottom mounts, I also used a 400ex top mount bolt for this.

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00215_zps472168fb.jpg

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00216_zpsb1b7b2d7.jpg


swingarm spacers, this is a 450r swingarm, the left spacer is a 450r, the right is a 400ex. inside the case between the 2 spacers, is a 400ex right side spacer cut down to fit inside so there is no slop in the swinger bolt. "cr250 bolt is fatter" A 450r swingarm with these mods and a 400ex front sproket, the sprokets line up like factory.

http://i953.photobucket.com/albums/ae15/johndoe83_2010/CAM00217_zps8104b473.jpg

The hardest part is fabbing everything up in such a way that it all fits and works after its installed, everytime you move something you have to make sure the pipe still fits, the radiator willl work, the spark plug isnt hitting...etc...

[Zakradu398]

Wow doesn't seem bad at all. I plan on using a cr250 pipe tho. I found another hybrid thAt used it and it looked fairly easy, plus my lady's dad is a boilermaker so he has most of the things needed for metal work. I appreciate the things you've posted up.

As for the kicker did you end up extending it or will a kicker from another bike work?

[JOHNDOE83]

Thats why you need 2 cr250 kick start knuckles and the 3/4 steel square tubing.

One knuckle you completly cut the big pin that the kick start slides on, this makes it almost square to fit in the square tubing, then you weld that into the square tubing.

The second knuckle, you cut the square tubing for the complete knuckle to fit in with the big pin sticking out, I believe I cut the square tubing at 3 or 3.5 inch's to clear the rear brake when kick starting.

After building this, I saw that cr85/80 had shorter kick staters, maybe do some research and possibly get a smaller kick starter lever to use instead of cr250.

Just something you may be able to improve on where I feel short.

Look in the top view pic of my build, you will see how it sticks out slightly and it does kinda get some leg rub, maybe with a cr80 kickstart you wont be so close.

Oh, I broke 3 kickstarts before using the square tubing, everything else bent or broke...fyi.

[Zakradu398]

Every single one of my friends have different bikes 2 or 4 stroke so I will have over 30+ different bikes I can try them from, Even a few backwards kicking quads :D

[JOHNDOE83]

Check this out, this guy and me built these at the same time.

http://www.exriders.com/vbb/showthread.php?s=&threadid=479502&highlight=rm250

The thread ends but he later posted vids and it turned out to be a AWESOME quad!

Look it up on youtube hes there somewhere.

[Zakradu398]

I will have to read that one when I have some more time. With the stock cr250 pipe coming out center, would I be able to simply heat and bend it?

[JOHNDOE83]

Originally posted by Zakradu398
I will have to read that one when I have some more time. With the stock cr250 pipe coming out center, would I be able to simply heat and bend it?

I was thinking of doing the same thing, I think we could possible cut the pipe by the expansion chamber and re route to come out in the center, I think if we got the right size tubing it could be cut bent and welded to the existing exhaust?

IMO that would be the best and easiest to avoid crimping.

[Zakradu398]

Could I just use steel tube and make a new stinger? I have access to a JD squared bender.

[JOHNDOE83]

Ya probaly, this is all custom work so as long as your comfortable trying something new the sky is the limit. :D

[Zakradu398]

Currently have zero experience with metal work but will never turn down the opportunity to learn something new or at least try :D