400ex to crf450 conversion parts list

[jamiesel]

If anyone has done a 400 to 450 conversion, I think it would be really cool to compile a list of everything that needs to be done.

If someone wants to jot the stuff down, I would organize it and make a pdf or something.

thanks
Jamie

[Pvt. Maggot]

lots of money.









:eek2:

this is what i know of
1) oversized radiator
2)engine mounts
3)i think you need different sleeves for the swingarm so the to sprockets line up
4) head stay is recomended unless the 400ex blot will work(not sure on this one)
5) aftermarket or gusseted OEM frame, personaly i would jsut spend the extra money and get the frame

please correct if any of this is wrong

[CHAUNCY]

Originally posted by nacsracer27
this is what i know of
1) oversized radiator
2)engine mounts
3)i think you need different sleeves for the swingarm so the to sprockets line up
4) head stay is recomended unless the 400ex blot will work(not sure on this one)
5) aftermarket or gusseted OEM frame, personaly i would jsut spend the extra money and get the frame

please correct if any of this is wrong

You forgot the engine;)

[jamiesel]

400ex's are coming down and motors are getting easier to get. I think this can be done for well under 10k if the 400 frame can be utilized. If honda won't step up to the plate. a kit should be offered. If anyone has done this in a ex frame, it would be great to hear how it went or goes or?

[Striker49]

Get Jeff (@Quadshop) to post a list of what they did if he will offer it. :eek: They had an aftermarket 450 and sold it for 13K...very nice. :D

[jamiesel]

hey mods... is exriders interested in getting behind a conversion kit? at least instructions? Inexpensive route with stock frame if possible.

[Mxbubs]

Bling bling.

:D

[Tommy 17]

the cheapest way to go for a 450f is the arens frame... its 2g with the frame rad motor mounts and a few other parts...

the only problem with it is that its stock geometry... it isn't a 500link, no link, narrow front or anything like laegers, walsh, gibson, etc...

but bang for the buck its the best out there by far... probably just as strong if not stronger then the rest... arens 250r frames are some of the best on the market...

[NTPracing22]

i wish aftermarket frames weren't so much. i'm gonna make a company and sell aftermarket frames for 1,500. i've been in Walsh's shop and i know how they make the stuff, i'll just steal thier jigs and metal and everything and weld it up. lol,jk..... a lot

[jamiesel]

I suspect that for 500.00 a 400ex frame can be modified if a shop really knew what they were doing and could do it on a regular basis.

Frame mod 500.00
Janssenn rad 300.00
Motor 3000.00
hoses 150.00
Kick start ext 50.00
keep the crf header 0.00
muffler and mod 250.00


Additions? Missing? Add to it

This could be done 400 ex engines are probably worth 1,000.00 to 1,500.00 used

Looking like a doable thing for around 4,00.00 to 5,000.00 if you have a good used 400ex 3,000.00.

[NTPracing22]

why not an R frame? i was trold the 450s mount right up if you lower the mounts. all you have to worry about is the angle of the motor so the chain will by lined up and won't snap when your rear shockl compreses

[jamiesel]

That is interesting.... I have a really nice 250r roller. Engines are getting pretty worn on a lot of those. Do you know of someone who makes the motor mounts or has done one of these?

[NTPracing22]

i don't know off the top of my head, but i know there are people that could do it. heck, you could do it yourself if you have the right tools. i'd do it, i just dn't have a motor to size up

[jamiesel]

If I talked to someone who succesfully did it, I would probably buy an engine to start the process up.

[86atc250r]

Where do you find the kickstart extension for $50?

[jamiesel]

Have 50 of them run at a macine shop and I would be surprized if it was more then 50.00 each. I could be wrong.

[jamiesel]

Things are looking up!

[Mxbubs]

I found a better way than having a spacer/bushing machined for the pivot bolt mount, in the motor.

I did that at first, but I kept bending and breaking pivot bolts.

So I drilled out my frame, put the stock bushings back into the yz motor, drilled out my swingarm bearing spacers and stuck a 5/8" bolt thru there. You can get a 5/8" bolt at a hardware store for around 4$. Its solid, and MUCH stronger than stock.

You WILL need a chromed masonry bit, 21/32 to drill out the swingarm bearing spacers. They are too hard for a regular bit.

My dad is a machinist, we found this is about the only way to drill thru these suckers.

Also drill the frame.

It should work the same on the CRF motors.

[Rad Rob]

MXBUBS,
Have you done a crf450-400ex conversion?
Have'nt done a yzf conversion yet myself. You actually found a bolt that long at a "hardware store"?
We do have a customer that wants to place a WR450 in a 300ex
frame! Maybe your suggestion will help out on that.
Thanx,
RAD.

[400exBro]

the crf and yzf don't have the same mounting points do they???

so i can't use the arens crf/ex frame to mount a yzf 426 engine??

[Mxbubs]

Yup....my hardware store carries 5/8" bolts up to 13" long.

We machined a bushing to fit the stock pivot bolt, I broke a titanium bolt we made, and a steel one....so I just went up to a 5/8" bolt. The 5/8" bolt is the way to go.