Jump to content
Sign in to follow this  

CR500 swap???

Recommended Posts

I really like those Service Honda cr250/cr500 engine bikes, cant afford one though. However, I own a 97 CR250 with a bad motor and I also have a 87 CR500 with a fresh motor. Would that 87 CR500 motor fit in the 97 chassis? I know the "stairstep" exaust pipe wouldnt work, perhaps a "lowboy" pipe from a later model would work? I think the chassis that Service honda uses is 2001-2003, I dont see much if any difference in the 97, as a matter of fact the motor in it now is an 89 model, it bolted in with no mods at all....I just wonder about the 87 500 motor, would the motor mounts be any different from the later model years that Service Honda uses?..What do you guys think?

Share this post


Link to post
Share on other sites

use a '91+ cr500 exhaust, reroute the coolant hose to the rear of the jug to clear the pipe, swap the rear case bushings with the ones from the 250 motor, drill the 500 cases with a 13/16" bit to get them in. you need to make spacers for the swingarm bolt, 4mm and 6mm. cut out the X brace and front mounts, retain the lower mounts. fab some front mounts and get a longer front bolt, we have a honda part number on banned. Fab a head stay and heat gun the tank. also use the shorty plug to give more room for the tank. br8ecm

Share this post


Link to post
Share on other sites
use a '91+ cr500 exhaust, reroute the coolant hose to the rear of the jug to clear the pipe, swap the rear case bushings with the ones from the 250 motor, drill the 500 cases with a 13/16" bit to get them in. you need to make spacers for the swingarm bolt, 4mm and 6mm. cut out the X brace and front mounts, retain the lower mounts. fab some front mounts and get a longer front bolt, we have a honda part number on banned. Fab a head stay and heat gun the tank. also use the shorty plug to give more room for the tank. br8ecm

Listen carefully to this guy and do it. It won't be that hard. I was able to carefully remove and re-use my front mounts, don't know with a generation 1 frame, though.

There are a bunch of picture rich tutorials on the sites listed.

Service Honda used different frames for different years. I think they used the gen 3 frames for a couple of years (03+ cr250's) and then the gen 4 crf250's for a few years. They started with your frame, I believe.

Share this post


Link to post
Share on other sites

the only way to reuse the front mounts on a gen-1 is if you stretch the frome out, its too close to allow room for the bolt head. we were selling kits (all out now) that included front mounts as wide as the frame so the nut nd bolt head were on the outside. I made one set of mounts (before we were making kits) by getting a 1" aluminum dowel, drilling a hole down the middle and cutting one side flat. Service hondas first bike was a '98. I guess AJ got frustrated by the fact that in '97 the cr250 got an aluminum frame and twin chamber forks, then in '98 the 125 followed, but nothing for the 500, so in '98 he built his own. since then they have always used the current chassis and always used 250 chassis, so with the gen-4s the went from the cr250 to the crf250. Goodluck, mang 👍

Share this post


Link to post
Share on other sites

As I said, listen to dgraves!

As for my front mounts, they were on a generation 3 cr250. I cut the mounts back so that the engine didn't run into them, re-drilled the mounts, had my welder fill in the original holes along with the rest of the welding, then re-drilled them again (his welds ran into the new holes). It wasn't very much trouble to re-use them for the newer frame.

For your generation 1 frame, Dannygraves is THE guy to ask about conversions. You got lucky to have his advice here.

Good luck!

Share this post


Link to post
Share on other sites

Thanks Danny,

I've also got a clean '97 250R that I intend to put an '85 500 engine in--maybe this next off season. Hope I can make it look factory!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...