400ex 2 stroke project

[yama450yfz]

does anyone know of anyone putting a cr500 2 stroke dirt bike motor in a 400ex frame I am interested in trying it but don't want to waste my time and money on something that will not work any advice please thanks

[big_poppa49]

2 stroker!!

that would be like smacking god up side the face!

[aDviSol2y]

Go to the Hybrid page, you will most likely find something there. I did see a guy on here do a really nice cr500 conversion. The issue with it is, the cr500 motor is not counter balanced, so you get a lot of vibration. Bolts tend to rattle loose and the vibration also works its way to your arms.

[hypersnyper6947]

someone on here has already done it. He used to post often, maybe he will come on here and show you. I have seen a vid of though and its pretty freakin bad ***

[fearlessfred]

i did one in the early 90s in a 250r. iwas warned by a friend who is an atv mechanic not to do it, that the vibrations were to bad, i wish i would have listened to him . the rear grab bar would break in halve from the vibs (3 of them) . Many of these have been built,and i have only heard one person and say that the vibs.were not bad and he even suggested that the quads that did vibrate bad were built over the weekend with crappy welders and zipties .he changed part of the frame and used the stock cr 500 exhaust. maybe his changes made the frame less ridged helping out with the vibs. i would definitly follow his lead because he is the only person i have heard say that the vibs were not bad , the power is incredable he has posted pics of his bike in the last day or so

p.s. i only used the highest quality zipties on mine

[aDviSol2y]

The one you are talking about is the green and black one right?

[aDviSol2y]

http://www.exriders.com/vbb/showthread.php?s=&threadid=322841&perpage=10&highlight=cr500 400ex&pagenumber=1

go to the second page. He has a pic. I'm trying to find the thread where he has the video.

[aDviSol2y]

http://www.exriders.com/vbb/showthread.php?s=&threadid=436482&highlight=cr500

more pics

[aDviSol2y]

http://www.exriders.com/vbb/showthread.php?s=&threadid=367965&highlight=cr500+video

video

[aDviSol2y]

http://www.exriders.com/vbb/showthread.php?s=&threadid=397131&perpage=10&highlight=cr500 build&pagenumber=1

more

[fearlessfred]

yeap thats the one

[aDviSol2y]

I haven't seen this guy post in a while. Maybe the bike killed him. :ermm:

[tayyo789]

http://www.exriders.com/vbb/showthread.php?s=&threadid=436482

[tayyo789]

whoops you already got that one;)

[bigbad400]

one i raced... i got spanked:eek2:

[bigbad400]

i raced him on a Kawasaki Mojave with a cbr650 crotch rocket motor in it at the kaleva drag strip in kaleva MI. i got so ridiculously beat, that thing is an animal!

[fearlessfred]

Originally posted by bigbad400
one i raced... i got spanked:eek2: that sure is pretty,how bad did it vibrate

[BuB400]

If you were going to put a cr500 motor in,I don't get why people say you feel vibration worse in a quad frame compared to a bike frame.

[honda400ex2003]

why not use some good poly mounts to help with the vibration? that seems to be a logical thing to do when working with something such as that. even rubber bushings would work good instead of mounting it direct to the frames. steve

[fearlessfred]

steve, i did that on the one i built years ago ,i used the shock eye rubber bushings off of a 250r shocks. for what ever reason it did not work, the bike ran fantastic,but vibrated terrible

[honda400ex2003]

i would not have guessed that. lol. i was thinking along the lines of rubber mounts that bikes use on the motors or the 400 uses in the swinger. i would think something like what we have for mounts with dampeners built in would be tremendous to help with any sort of stuff getting to the bars. i guess not though. steve

[honda400ex2003]

something like this is what i was thinking could be used. mount it between the motor and the mount to help absorb the vibes.

[fearlessfred]

i built mine in the early 90s ,i did not have things like this forum to look on for info. i used what i had.

[JOHNDOE83]

I was looking into doing a cr500 conversion before I started my turbo project, I weighed the odd's and did a price check and the cr500 conversion was gonna be atleast $1500....so I went with the turbo project.

All the motors on ebay are atleast $800 for a decent one, and the whole entire bike goes for around $1000, which would be a better deal, coming with all the parts you would need, but I would wanna port, bore and stroke one or do atleast a motor overhaul before completely installing, I would then sell the cr leftover's and ex motor for cash back.

Or ex motor the cr500 chassis...lol... thats a good idea.

I really would like to do this, good luck if you do, I really dont give a F$%^ if it vibrate's, loctite everything and deal with it....lol.

[atv fan 28]

Originally posted by big_poppa49
2 stroker!!

that would be like smacking god up side the face! what you cant handle the power of a 2 stroke?

[honda400ex2003]

Originally posted by fearlessfred
i built mine in the early 90s ,i did not have things like this forum to look on for info. i used what i had.

ah cool, lol. sounds cool. It is awesome to build something that way though, when it all comes together you can say that it is one of a kind. steve

[fearlessfred]

yea, it is cool ,i have one other crazy prodject left in the garage, its my old desert sled 250r race bike soon as i learn to post pics on here im gonna post it. it has 16 inchs of travel up front and 18 in the rear that will get u thinking how is that possible ( or maybe hes full of crap)

[tayyo789]

Originally posted by fearlessfred
it has 16 inchs of travel up front and 18 in the rear

thats what i'm talkin about :devil:

[86 Quad R]

i've built 2 hybrids over the years.

the first was using a power valved 98 yz250 and didnt cut any corners in doing so. the entire tranny was cryo'd and the works, i used all rubber mounts and the thing still vibrated ur teeth out of ur head and all bolts, nuts and cracked many mounting tabs. dont get me wrong, it would flat foot run but was a total waste.

the second was using a trx250 engine(counter balanced) with a 4mm stroker crank with the porting to match. with a extended width suspension and the shorter wheel base, this thing was like riding a blaster on steroids. i kid you not. was amazing in the tight woods and trails and would have upper revs for the dunes and sand bars. the power was very controlable. the engine had enough torque in the upper gears that when getting traction when she hit the pipe could literally reer up on the drive side rear wheel.

was a great ride for any adrenaline junky. :cool:

[00.400ex#55]

Originally posted by aDviSol2y
I haven't seen this guy post in a while. Maybe the bike killed him. :ermm:

Im still here, so is my quad.


Mine does not vibrate very much at all with this set up. Its noticable when when stopped but goes away as soon I let the clutch out and put stress on the motor. Thats also one of the reasons I switched to some heavy 20in HD's. The only thing thats has broke from vibration on my current set up was my pipe mount. I used a sea-doo 700 somthing rather pipe hanger and its been good ever since.

[jcs003]

Originally posted by 00.400ex#55
Im still here, so is my quad.


Mine does not vibrate very much at all with this set up. Its noticable when when stopped but goes away as soon I let the clutch out and put stress on the motor. Thats also one of the reasons I switched to some heavy 20in HD's. The only thing thats has broke from vibration on my current set up was my pipe mount. I used a sea-doo 700 somthing rather pipe hanger and its been good ever since.

got any pics??

[00.400ex#55]

Originally posted by jcs003
got any pics??

pics of what, the exhuast mount?

[jcs003]

Originally posted by 00.400ex#55
pics of what, the exhuast mount?

of the 500 2-stroke in the 400ex.

[00.400ex#55]

Look at the links on the first page, thats my quad.