Different 89 xr600r questions

Hi everyone. I'm new here and have a few questions. Would appreciate any help, comments, answers, suggestions, etc. If I'm out of line jumping with a bunch of questions, let me know.

I just bought an '89 xr600r in a box, well, in a bunch of boxes.

The prev.owner had it set up as a Calif. plated motard bike, crashed it, damaged the subframe, stripped it down to the bare frame with plans of re-working the rear subframe to lower it a bit, then decided to move to hawaii. Subframe has been repaired, but not modified.

Pardon me if I ramble a bit as there's kind of a lot to cover.

Bike came with three wheels, I'm not sure if any are original to an xr600r.

1) front w/21 rim. Looks honda stock. 4 bolt rotor.

2) front w/ DID 2.5x17 rim. 6 bolt rotor. Generally heavier hub than the 4 bolt.

3) rear w/ (about) 4.5x17 sim (sun? sum?) rim - looks correct for the 150 tire that's on it (unlike the 120/70 squeeeezed onto the 2.5 front rim...).

Can anyone tell me which (if any) of these might be a wheel from an xr600r?

Engine is supposed to be a 628. I have a xerox of the set-up manual and parts list for the (HRC) "engine power up kit" for a '91 (also applicable to '88-'90) xr600r. Claim was that it's a 628 and the PO seemed to be completely on the level and honest with me. I got no weird vibes from him and so far, everything he told has checked out.

Kit specs are: 100mm bore, 628cc, more duration on cam, 10.6:1 comp.

Is anyone familiar with this kit? What power (or power gain) can I expect? I will probably use a white brothers pipe (new one came with the bike) and the stock header (I think it's the stock header...). I believe the carb is stock, but like everything else, it's in a box w/o and documentation.

I will probably be setting the bike up as a street/motard/roadrace bike - I currently race AFM (250p) and have been considering formula singles as another class. I'd also like to be able to throw some dirt wheel on it and go to baja, but that's secondary right now.

Suspension looks stock. Showa shock and there appears to be a single adjustment on the bottom of the forks, I presume rebound damping. Schreader valves on the fork caps. Are there any common suspension upgrades? What modern forks will bolt on (either w/ or w/o triples)?

I presume race-tech emulators are available and do their usual stuff. Is anyone else using one of these on the street and upgrading the suspension?

Any common engine gotchas or known weak points - particularly ones that might be exacerbated by the 628 kit?

My plan at this point is to paint the frame (minor surface rust), put everything back together, and see how it runs. I know it's a better idea to pull the top end, verify that I really do have the 628 kit, and get an idea of blowby, valve condition, big end play, etc., but I've already got another engine to rebuild (the "A" race bike engine), so I'm kind of tight on time.

If it were a stock xr600, I'd have fewer concerns about just putting it back together; all the xr's seem pretty bulletproof!

Any paint recommendations? I'm probably not going to powder coat it at this point. Most of the existing paint is there (sliver), and I'm more interested in getting a baseline on what I have before I do much more. Can anyone recommend something between a rattle can and powder coating?

Any other comments or suggestions at all?

Thanks in advance,


Only the 21 inch front wheel sounds stock, The forks are an upgrade also. The screw on the bottom of the forks is for compression damping. Clockwise for more counter clockwise for less. If your front axle is 15mm your forks are '91 or '92. If your front axle is 17mm your forks are '93 or newer. If the forks lack the lug to prevent the speedo drive from spinning you probably have CR forks. Good Luck! :applause:

You should have a 3.5" rim to properly match a 120 tire, although a 3" may work. I don't know how the motard guys do it, but that is the rough rule for roadrace rubber,anyway.

I had an '86 XR600R.......I ported the head, and put a White Bros. cam on.....the thing was a rocket, even with stock head pipes and carbs. You may want to check the cam lift against a White Bros spec to see if you should use the better valve springs. The stock springs can bind, depending on high the lift is.....although if it is the HRC kit, it should be pretty complete. The 100 mm bore sounds right. Mine was bored just 1mm over, which was 97mm, I believe.

I thought the silver frames didn't come into the picture until well into the 90's.

I have another XR600 I just picked up cheap, so it's nice to see others out there with projects in mind.

Good luck with it.

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