HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
richklutz

1991 XR600R Cylinder Head Compatibility Years??

5 posts in this topic

Hi all,

I bought an XR600R that was abused pretty bad by a previous owner and decided to take it on as a project hoping for the best and of course going way over budget. I completely disassembled the bike and sent the motor to AMI in Puyallup for cylinder resleeve and a rod kit. They told me the head was about to go and I decided to risk it and put it together and hope to not have to spend any more money for at least 2 or 3 rides. Wrong.

The bike is dumping oil in to the chamber after startup and I'm sure I should just replace the un-rebuildable (according to AMI) head. Now, I found some parts on eBay and Craigslist, etc., but get mixed information over head compatibility. Some say '88 to late 90's fits my bike, but when I see closeup pictures of older heads they don't look different (like '86). Of course some bikes have black motors, while mine is unpainted aluminum, but other than that what's the difference?

Muchas Gracias.

Share this post


Link to post
Share on other sites

Thanks for the reply to the two guys who did, but where did they go? I wanted to re-read them but they were gone.

Anyway, does anyone know about buying rebuilt heads or a good source for used XR motor parts?

Share this post


Link to post
Share on other sites

Yes it seems my reply has been lost in cyber space!!

Let me know if you find a good source for 2nd hand XR600 parts!!

Share this post


Link to post
Share on other sites

Heres, a repost of what I said yesterday!!.....

All the 600 and 650 RFVC heads are similar and are interchangeable to a large extent.

The cyl head dome sizes change (gives more or less compression), the decompressor systems changes (XRL/XL/XR stlyles) and the cam lobe spacing is often different. Hence its important to have a matching head and cam cover as the cams and lobes wont meet up!

The later XRL cam chain and sprocket is also different. For example, my XR650L (NX650) takes a wider camchain than the earlier lighter type on the XBR500.

The early XL/XR cranks are also a lot lighter than the later style as used on the XRL (The XL600 has wasted crank webs for example - revs much faster than a XRL!)

AFAIK, the valves and springs are all pretty much identical. The early heads tend to crack btwn the exhaust ports and the spark plug hole.....then the valve seats fall out ......ouch!

Lots of other changes in gearbox, selector direction and primary drive ratios as well of course.

Anyway, I hope this helps!

Share this post


Link to post
Share on other sites
Some say '88 to late 90's fits my bike, but when I see closeup pictures of older heads they don't look different (like '86).

The intake ports are different on the older heads, as they were designed for two seperate carbs.

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

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0