400ex motor in 250r frame?

[mac_ando]

just wondering if anyone has tried it. i see alot of other swaps. but have never seen this one.

[C41Xracer]

i tried and it didnt work. the top frame rails are to low

[250Renvy]

It's a good in theory, but like anything the 4-stroke motor is too big and heavy for the stock frame. It would involve lots of hacking - your best bet would be to get a hybrid YZ426 and change it up.

When I was looking at the best motor for a trail quad, I first thought of the 300ex and started along that route then decided the Z400 would be better as there are more options available and it's a liquid cooled motor.

[jcs003]

you can find 400ex frames anywhere cheap. just go that route.

[woodsracer144]

Originally posted by mac_ando
just wondering if anyone has tried it. i see alot of other swaps. but have never seen this one.


i was thinkin that same thing!

[mac_ando]

well i've started on mine. i can make it work. i picked up an 86R ... i'll keep you all posted

[C41Xracer]

this is going to be interesting

[250Renvy]

Originally posted by mac_ando
well i've started on mine. i can make it work. i picked up an 86R ... i'll keep you all posted

I can tell you 100% that you can't make it work without lowering the lower frame rails or getting a custom gas tank made.

If you decide to mount the motor through the swingarm please let me know what you use to make it fit as the hole is bigger than the swingarm bolt.

Check my sig for my 300exr build. There are some pics of the 300 which is slightly smaller in size but similar dimensions as the 400ex. I tried the 400 and Z400 and they are bigger motors that hit the top. It just barely works with the hybrid frame, let a lone a stock frame.

If you are anywhere close to harrisburg, look up HRE - he would have some good advice.
HREATV.com

[mac_ando]

Well i think you should get your percentage meter checked or re-calibrated.. HaHa just kidding. cuz i have everything all figured out. as far as the swing arm bolt. the 400 and 250r will interchange. (same bolt!!!) . And you can't run the swingarm bolt through the motor anyway. cuz the motor won't go back that far.. the bottom frame rail that runs across under the swingarm is round, and the 1 on the 400 is flatend more. So you have to make a special rear motor mount. i made mine out of the old R mount and a piece of C channel. this rear mount alows you to sit the motor forward and down slightly. At this point the motor wasn't the issue anymore. It was the throttle cable comming up out of the carb. (you know the big elbow). so i took the cable out of the top and mounted it into the plastic side cover. and it still works perfictly. then you have the issue with the air filter tube. I had to notch & reinforce the top rail that runs across above the rear shock mount. well you get the point!! I just got all my stuff back from p/c and i'm starting the assembly.

[250Renvy]

Post pictures - start a thread then and show assembly. Show me what you did to avoid having the head hit the top frame rails and how you are going to get the gas tank to fit without getting a custom one made that clears the top of the motor as well.

I tried doing this in a stock dimension frame and it just wouldn't fit. The hybrid frame is still tight and it's got the extra inch clearance.

[mac_ando]

WOW!!!! I did'nt mean to stike a nerve!!!! Take it easy.. I have already had this thing all mocked up. the head fits within the frame rails. and the only thing that the tank tuches is the carb. but I won't have to get a custom made tank.. i think the key to it is with that back motor mount. cuz it let me drop the motor alittle.

http://i39.tinypic.com/seljyd.jpg

http://i43.tinypic.com/a1s876.jpg

http://i40.tinypic.com/okweb6.jpg

[mac_ando]

after powdercoat

http://i42.tinypic.com/2qas16x.jpg

back motor mount

http://i39.tinypic.com/rupcno.jpg

notched for air boot

http://i39.tinypic.com/6foaxz.jpg

battery box

http://i42.tinypic.com/25r1mk1.jpg

arms are on

http://i42.tinypic.com/2iqjoyb.jpg

[mac_ando]

Idk what your doing wrong ... but i hope this helps..

[250Renvy]

No nerve was hit, I just wanted to know and see visually what you did because my motor is sitting in there low and there was no way to get the gas tank to clear. I had to make a special bracket and tank bottom from aluminum to get it around the head.

I still have the inside frame rails though, so maybe you got it to fit lower by taking them out.

Is that battery box custom or did you weld the stock one in there? That's another problem I'm having - the battery. I put it on the side of the subframe like the 400ex but I don't like it there.

Also, did you forget about the oil tank and oil cooler?

[woodsracer144]

[QUOTE]Originally posted by mac_ando
back motor mount

http://i39.tinypic.com/rupcno.jpg

notched for air boot
[QUOTE]

how did you get the sproket to line up with the pivot bolt? got any motor pics pm what you did?
what year motor from a 400ex did you use as well? thanks

[jcs003]

not to sound insulting. but why would you hack up a 250r frame to put in a 400ex motor. 400ex frames are practically free.

the reason people (servicehonda.com) did it is 250r frames are hard to get ahold of at a cheap price.

[mac_ando]

Originally posted by 250Renvy
No nerve was hit, I just wanted to know and see visually what you did because my motor is sitting in there low and there was no way to get the gas tank to clear. I had to make a special bracket and tank bottom from aluminum to get it around the head.

I still have the inside frame rails though, so maybe you got it to fit lower by taking them out.

Is that battery box custom or did you weld the stock one in there? That's another problem I'm having - the battery. I put it on the side of the subframe like the 400ex but I don't like it there.

Also, did you forget about the oil tank and oil cooler?

No.. the battery box is from a 300ex. And i had to weld it in. i had the same setup on my 460EX. i like to have the side of the subframe clean. No i did'nt forget about the oil tank. im using one from a z400 cuz it it looks alot more like a natural fit. I just Can't beleave that nobody has done this yet. so do you think that i should try out for QOTM when its done?

[250Renvy]

If you could do me a huge favor and take/post as many pics as possible when you start assembly as well as state other problems you've encountered because I need to know if it's worthwhile to do this mod to my frame. This is how it sits now so you can see what I'm working with.

http://i75.photobucket.com/albums/i289/250Renvy/300exR%20build/DSCN2571.jpg

This is how my other frame is starting out - needs some work still.

http://i75.photobucket.com/albums/i289/250Renvy/Laeger/DSCN3574.jpg

[250Renvy]

To answer your question, I have seen this done before, but the lower frame rails were lowered and widened.

I'd like to see a pic when the motor is in as well to see how much lower it sits in the space in the center of the frame.

Do you think it would be hard to duplicate your motor mounts and the way you see using a Z400 tank.

See the pic above with the disfigured frame and how it's got 2 posts on the rail? That's all for a 400ex tank.

[mac_ando]

Originally posted by jcs003
not to sound insulting. but why would you hack up a 250r frame to put in a 400ex motor. 400ex frames are practically free.

the reason people (servicehonda.com) did it is 250r frames are hard to get ahold of at a cheap price.

No man.. i'm not insulted. but you know what? I would'nt give you a dime for a two stroke! no offence to those of you that like them. But i just don't care for them. the only reason why i used a 250r frame over the 400 is that the R's handle better. also apparently I'm the only one that has done this. so that in itself was worth it (to me anyway) and it's nothing to me to "hack" up an R frame. it's just another frame to me. Again, I'm not trying to insult anyone.. Just my 2 cents... if you guys have anymore questions let me know.

[jcs003]

Originally posted by mac_ando
No man.. i'm not insulted. but you know what? I would'nt give you a dime for a two stroke! no offence to those of you that like them. But i just don't care for them. the only reason why i used a 250r frame over the 400 is that the R's handle better. also apparently I'm the only one that has done this. so that in itself was worth it (to me anyway) and it's nothing to me to "hack" up an R frame. it's just another frame to me. Again, I'm not trying to insult anyone.. Just my 2 cents... if you guys have anymore questions let me know.

i have a 400ex and a 250r and i feel the 400ex handles better. i am doing a 250r/400ex hybrid as we speak and i will be able to tell you real soon what s the best bike in my opinion. you can see my thread and know i did it well.

but, to each his own. work hard, ride hard.

[mac_ando]

Originally posted by woodsracer144
[QUOTE]Originally posted by mac_ando
back motor mount

http://i39.tinypic.com/rupcno.jpg

notched for air boot
[QUOTE]

how did you get the sproket to line up with the pivot bolt? got any motor pics pm what you did?
what year motor from a 400ex did you use as well? thanks

alot of mesuring.. to make sur the sprockets line up. after you get those in line the rest is cake. not sure what year motor is. but they r all the same. i'll get some more pics out along the building process

[mac_ando]

Originally posted by jcs003
i have a 400ex and a 250r and i feel the 400ex handles better. i am doing a 250r/400ex hybrid as we speak and i will be able to tell you real soon what s the best bike in my opinion. you can see my thread and know i did it well.

but, to each his own. work hard, ride hard.

i hear ya man.. I'm a firm beleaver in Ride what makes you happy. I just like to have something differnt. I want to be able to go out to the track or trail and not see 20 of my bike.

[mac_ando]

this is a rough mock up of the oil tank and cooler

http://i39.tinypic.com/301g5jb.jpg

this is the mounts for the oil cooler (on each side) and the mount for the coil (in the middle)

http://i43.tinypic.com/mwf8mw.jpg

[mac_ando]

a few pics of the oil tank and shocks installed.

http://i40.tinypic.com/2309x.jpg

http://i43.tinypic.com/ng95wx.jpg

http://i43.tinypic.com/b4xpv9.jpg

http://i41.tinypic.com/303actd.jpg

[MyKe2g3]

Nice work man Im glad you attempting this because it just shows it can be done and still look good. As for the other guy saying the 400ex handles better than the 250r hmm i dont think so. Good luck with this project.

[woodsracer144]

so is this a rather easy build... how did you get the sprokets and pivot bolt to a line? lower the front mount a ton or what.. how much did you have to move it? thanks

[mac_ando]

Originally posted by MyKe2g3
Nice work man Im glad you attempting this because it just shows it can be done and still look good. As for the other guy saying the 400ex handles better than the 250r hmm i dont think so. Good luck with this project.


thanks man! Ya, it's been a prooven fact that the R has a better handleing geometry ... but everyone has there choice of bikes. thats what make it all fun

[mac_ando]

Originally posted by woodsracer144
so is this a rather easy build... how did you get the sprokets and pivot bolt to a line? lower the front mount a ton or what.. how much did you have to move it? thanks


you know, it has'nt been to hard of a build so far. the hardest part ( well what took the longest) was making sure that the sprockets lined up. i accually used the stock mount from the R in the back (just modded it a little). i had to make my own front mounts. by making that rear mount it moved the motor forward and down enough. hopefully i'll get the motor done and in this weekend.

[mac_ando]

well i got the motor all together and in the frame. here is what she looks like so far.


http://i43.tinypic.com/1zvvpy1.jpg

http://i40.tinypic.com/35jgeh2.jpg

http://i41.tinypic.com/2mnkqdh.jpg

http://i40.tinypic.com/2lazr54.jpg

[250Renvy]

It looks 100x better with the black motor than the red one.

Once you get it together and start riding it, I'd love to hear a report on those tires.

When you get a grab bar on there it would help me a bit if you could get a shot showing the underside of the motor - I'd like to see if it's a must to remove the middle braces or if they can just be moved. Thanks.

BTW it looks good - are you going with white or black plastic?

[mac_ando]

The tires worked good for me on my 460. so im sure they will be just as good on this bike. i'm going with white plastic... yeah i like the look of the black motors w/ the fins ground. i got a little bit more done today. here are some pics of the tank /carb clearance. I think you will have to cut the bottom rails out, but you will have to try it first. idk how differnt those frames are setup. honestly i think the carb is a bigger issue than the top of the motor.

http://i44.tinypic.com/2nar7t4.jpg

http://i40.tinypic.com/24mhzqh.jpg

http://i40.tinypic.com/hvz6ux.jpg

[timmy400exfast]

how id you get paint on the block and head without painting the cooling fins

[mac_ando]

I just paint the cylinder and head and then grind the fins. If you are going to do this.. the only paint i found that will work and stay nice is PJ1 1500 degree paint for the cylinder and head and 500 degee for the bottom end.

[mac_ando]

I've been having trouble posting on this thread lately. i've got the pipe installed last week. the build is moving on slowly. i also sit the pastic on, just to see what it looked like. my graphics should be here thursday. i hope to be done soon.

http://i41.tinypic.com/27yd1t.jpg

http://i39.tinypic.com/28ama8x.jpg

http://i40.tinypic.com/bi7cjp.jpg