Decisions, decisions.....older kx500, or newer cr500

[reknelb]

After retiring from road racing last year I've been getting the itch to do some competitve riding again. I was thinking of doing some hare scrambles next year. I am just finishing parting my cr250 and will be ready to purchase a bike in about a week. My buddies both have the new 4 strokes but I've been craving a big bore 2 stroker. I Found a '90 kx500 for sale realitivly cheap, also found a '97 cr500 for the same price. Apperently all the swing-arm and shock bearings have been changed on the kx and he says its ready to ride. The guy came down 500 bucks on the cr which concerns me a little. Either he is afraid of it, or there could be some hidden issues? What do you guys think? Are the older kx engines the same as the newer ones, or did they change some power valve parts? BTW the kx is about 20 min. away and the cr is a little over 3 hours away. Any suggestions on what to look for when checking out the kx?

Also, how much maintenence will I be doing on the power valves? I'm not really familiar with how they work. I've never messed with them on the cr250. I'm a relatively mechanically inclined guy as I've done alot of rebuilds on 4strokes and rd400's during my road racing days.

[mikesmith]

The KX500 hasnt really changed that much,but I would look at and ride both bikes and see what ones in the best shape for the best price(how much by the way?),and tell the KX owner about the newer CR for the same price as a barganing tool to lower the price some.As far as power valves dont sweat it,youll have to learn the first time or so and then itll be easier.Besides Rick has some good "how to" articles allready written up.Good luck and hope you get the KX!

[GreenMachine]

there are many things to check when looking at older bikes, but one of the things that most people look past is the case. remove the stator cover and check the end play on the crank. Does it wiggle up and down. If it has excessive end play or wiggle in the crank it could be bad bearing. If you want to dig further remove the flywheel and check the seal. if it moves in the pocket then the case is really bad and will be hard to get fixed. if its tight then you have bad bearings or a case thats just starting to go bad and is about a $100 or so to have fixed up.

Just my 2 cents.
Wig

[reknelb]

I'm not sure someone would let me start tearing engine cases off. Would be nice to at least check out the left side crank seal though.

[gowen]

I've run through quite a few CR's and I've noticed that the CRs have chronic issues with the (a linkage locking up unless taken care of (b spokes coming lose no matter what (c kick starters slipping (d clutch baskets groving badly. I do have a '90 KX and will admit that it was run in the ground and has needed alot of work. But, it also came with no plastics and was sitting in somebodys backyard for about 10 years. So, that was my fault. I had my PV's cleaned once a year or two ago, still is like new.

[reknelb]

Sounds like alot of the problems I had with my cr250. Kicker not engaging, basket grooved badly, and every bearing/bushing in the shock linkage and swingarm were shot.
The owner of the kx did say he replced all the swingarm and shock linkage bearings recently so that's a plus.

[KXcam22]

reknelb,
  When buying a used bike my two favorite tests are, a compression test (since it is easy) and I like to take the pipe off and check the piston and cylinder wall with a flashlight for scores, seize marks and general condition.  It's easy and quick to take off a pipe and with a 500 you can see alot (huge exhaust port) and can fit your finger in there to see how much the piston wiggles.  Also on the KX look through the exhaust at the transfer ports to see if the plating is flaking off.  Engine and wheel bearings are cheap. Look for other things that cost big $$.  Also, as I recently found out, determine which owner is the most knowledgable bike mechanic.  I just got a mint 03 xr100 for my son (from a non-mechanic) and got a few big $$ surprises I didn't expect caused by complete lack of bike savy. My '92 KX is setup for HS and easily bests all the KTM's out there. Still has the original top end (not for long) so they last pretty good. I think the KX is better for hare scrambles but it's hard to argue with a '97CR for the same price.  Either one will be a blast.  I used to roadrace a fully preped RD350LC.  Hope this helps.  Cam.

[reknelb]

Went and looked at the '90 kx500 yesterday. Started with 4 kicks, ran pretty good, even idled  The only problem I could really find on the thing was a leaking rear shock seal. The rear end of the bike sat about 2" lower than normal. Are the rear shocks rebuildable?

[gowen]

Reknelb, yes, they are pretty simple to do also, if it is just leaking, there is a thread here by Rick on how to rebuild the shock.

[enmerdeur]

I just bought a used 97' CR500 that was set up for off road.  When I buy used bikes I have to go through the whole bike before I can ride it.  That's just the way I am.  Anyway What I found on mine is that the piston had a 1 inch long hair line crack on the skirt (intake side).  Apparently a common problem on OEM pistons after some use with the CR.  I have seen photos of what happens when people let this go too long (not pretty).  So in went a Wiesco.  

Shock linkage and shock heim bearings were shot also.  Other than that everything checked out well and just need some grease and cleaning.  Serviced the forks and have changed brake pads.  I guess I have an extra $400 into it but everything is to spec now.

Have not dealt with the KX 500 before so no insight from there.

[hughes]

Just to support what Gowen said. They are pretty simple to rebuild. I just rebuilt mind this hoilday(first time for me). Rick's sticky post really helped me. The toughest thing I think was getting the right tool for the shock bladder to remove it. Rick's sticky tells you how to make a slide hammer type tool(I think). Good Luck

[FastKX500]

Went and looked at the '90 kx500 yesterday. Started with 4 kicks, ran pretty good, even idled  The only problem I could really find on the thing was a leaking rear shock seal. The rear end of the bike sat about 2" lower than normal. Are the rear shocks rebuildable?

even idled? ..mines a 89 and it runs like a top fuel dragster..lol its not stock and i dont know if the engine was rebuilt but it couldnt run better for an older bike..id like to race a new 500, im pretty sure i can beat any stock 04 500, id go with the 500 man, 90 was a good year