cr500 motor 400ex frame

[lester985]

has anyone done this mod if so how hard is it to do all help would be nice

[SLABORDE]

I HAVE A CR500 ON A CUSTOM FRAME

[lester985]

was it a hard build because im thinkin of selling my 400ex or just sell the motor and use the frame to put a cr500 in it im from louisiana too from larose around houma

[SLABORDE]

IT TOOK A WHILE. IT VIBRATES LIKE HELL EVEN WITH A BALANCED CRANK. IF YOU DECIDE TO SELL YOUR 400 MOTOR I MAY ME INTERESTED

[hondamx213]

im in the middle of putting a cr500 in my 400ex frame, so far the swing arm bolt for the 400 is smaller then the 500. Im thinkin bout getting a sleeve made but on a good note the sprockets align perfect.

[fearlessfred]

i built one in the 90s in a250r frame,a good mechanic friend told me not to because of the vib. i wish i would have listen to him it was very fast ,but would vibrate the rear grab bar to wear it broke off the bike [ three grab bars] it would vibrate your arms to wear u couldnt hang on

[wannaride4]

I have been wanting to hotrod a qude, I have kicked around lots of idea's. First is to big bore and NOS. the other thing I have seen in a couple hillclimb bikes is a snowmobile motor in a bike so why not a quad? And I have thought of the 500 cc motor in a quad. My question is why does it vib. so bad?

[fearlessfred]

no counterbalancer , a really big piston and the atv frame is more ridged than the bike?

[hanzito]

i have a 89 cr500 motor in my 06 yfz 450 chassis. i raced it flattrack this winter. hooly shiznit fast. but have had a COUPLE ISSUES from vibration. most noteably my muffler keeps breaking where the exhaut pipe comes into it. i have aantivibe stem so i dont notic th vibe whren i am ridding, but still working the bugs out of it,

[aDviSol2y]

There is a guy on these forums that did the cr500/400ex conversion. He stiffened the frame with a removable crossmember. It was black and green. Search the 400ex forums. It was a nice build. He did a good job.