Love my new (to me) 83 xl600r, but please help!

I'll cut to the chase. Top end was redone 30 miles before I bought the bike. Ran like a top. Absolutely purred! Then, all of a sudden started making a metallic ticking noise in top end one evening. My novice investigation led me to believe I had a loose decomp valve. Days later, I started the bike...let it idle to warm on...just as I was about too pull clutch and shift to first, it died. I went to kick it over...NO COMPRESSION. Here one second, gone the next. I know this may still seem vague, but ANY SUGGESTIONS ARE MOST WELCOME! THANK YOU SO MUCH!

Edited by danstar250
Misspelled words

On further investigation, I found that whoever did the last valve clearance adjustment (before I bought the bike) must have forgotten to tighten the locknut for a tappet adjustment screw. The locknut and screw are both gone. It happened at idle, and it lost compression and killed immediately. No major harm done, right? Now, I'm wondering...the screw and nut vibrated loose from above the intake valve (toward rear of bike) on the right side (kickstart side). I'm pretty new to bikes, and not a trained mechanic. Any suggestions on the best course of action? I've got some ideas, but I'd rather hear from experts and not suggest something myself that ends up being a stupid idea.

Still hoping someone will have some words of wisdom to help me in my above mentioned troubles. Anyone? Please don't leave a newbie hangin'! :thumbsup:

Worst you could do is replace the screw and find the screw and valve top so they arent in the motor. Tighten it down to spec and adjust both valves. Motor shouldnt be toast unless something fell into the valve.

first order of buisness is find that screw and bolt,thy're in there somwhere

I'm with you so far. What I'm really wondering, is where do I start looking? I know that's a rookie question, but I don't want to go big immediately if not necessary. Would probing inside the valve inspection covers with a magnet be worth the effort? I'm assuming they could be down in the crankcase though. Am I right on that? I'm not sure if I have to pull the valve cover off, or pull the right side case cover off. If the valve cover needs to come off, is that do-able without dismounting the engine from the frame? Thanks much for the help!!

I'm with you so far. What I'm really wondering, is where do I start looking?

Take off the engine side covers and look around for the missing pieces. They may have fallen down the timing chain opening. Best scenario they are lying in the bottom of the engine undamaged. Not so as you can use them again but more in that if they have not been damaged then they have caused no damage in their travels.

My XL500R had a screw, washer, chewed up spring and 1 gear tooth in the "sump". Got them out before any further damage. Had to replace a thread with an insert. Replaced the bolt, washer and spring. Still do not know where the gear tooth came from.

Good hunting.

Edited by picinisco

Start from the top and work your way down. Valve cover will have to come off first. You might get lucky and find them under the valve cover. Otherwise the clutch cover will need to come off next. Actually, first thing I would do is drain the oil, you never know, they might come out in the oil, but I doubt it.

Hi Danstar250,

I'm in St Francis, MN.

You've received some good advice here. If your lucky it didnt cause any other damage. Pull the rocker cover and see how it looks. If you dont find the bolt, etc, you can use a telescoping magnetic probe. Fish it down the T-chain and hope for the best. More than likley you'll need to remove the clutch cover too. Dont give up, you have to find that hardware. Good luck, Eric

Well, first of all THANK YOU to all who have replied. The advice has been helpful. My first instinct was to remove the valve inspection covers and probe with a flexible magnetic tool. This resulted in finding both the tappet screw, and the lock nut. SUCCESS...I thought. New hardware and a valve adjustment, and I'd be back in business. WELL...on further inspection I realized my troubles were far from over. As I turned the motor over manually and looked in each inspection hole I realized that the left side of the valve train didn't move. The cam didn't seem to be turning over there. Sure enough! I've now pulled the motor and removed the valve cover. The cam shaft is BROKEN IN HALF!!! :thumbsup:

Here's a pic:


Now, since I'm not a trained mechanic I REALLY need some advice! I hope to find a used cam at a huge local bike salvage place. I'm especially concerned with how to ensure proper valve timing. Also...can I replace the camshaft entirely from the top end by simply remove the cam chain sprocket and removing the old/reinstalling the new?

Any advice or instructions, even if they seem obvious, should help me not make a mess of something that looks like it should be fairly straightforward.


How long have you had the bike?

Whoever worked on it screwed it up.

If it was the previous owner I'd be getting ahold of him (if recent purchase).

If a shop did it and you have receipt (or previous owner does) I'd complain to them.

I'm currently trying (unsuccessfully) to find a used cam. They seem to be in short supply.

first order of buisness is find that screw and bolt,thy're in there somwhere

i second that. you have GOT to get that screw and nut out of there before you do anything. i wouldnt even think about kicking her over untill they are found. if you have to spin the crank for any reason, remove lt. side case cover cap and turn her over slowly and gently w/ the apropriate socket and driver. that screw and nut WILL surely do major damage if not removed. hopefully they are still up top and not in a valve seat or in the jug.

guess i should have read on that you found the culprets'.

Edited by neversinksmith
im inpatient

Well done with the bolt and locknut. My 350 is almost identical to the 600, and you can replace the camshaft from the topend by removing the two camshaft sprocket bolts, slipping the sprocket off the boss on the camshaft, and removing the old camshaft. As for valve timing, you really need to get a workshop manual. Good luck with the camshaft search, there must be plenty of parts at bike wreckers, or give ebay a try.

If you get stuck finding a camshaft PM me. I've got a camshaft out of an XR600 that will probably fit you can have for the cost of postage.

I purchased my parts through the TT store and used my new member discount. I can't go wrong with new OEM parts, right? Everything I needed came to $190 shipping included. Could be worse. Thanks for the offer of a used xr cam. I'm glad to know that, as I was hoping, the whole cam replace can be done from the top end. As far as timing is concerned, I see a timing mark on both the end of the camshaft, and on the sprocket that mounts to the cam boss. So, if the new cam has a timing mark on it, I should just be able to mark the chain where the sprocket timing mark was, and slip the cam in with the same alignment as it had before? Nothing should have moved or slipped since the cam chain end is not the end that broke off? Am I thinking this through correctly? If anybody needs to see pictures to be able to help, just let me know. I can easily provide them. Thanks!

just don't let the crank move while doing this. there is timing marks on the flywheel (rotor) they should line up. just don't let the timing chain skip a tooth on the crank. if you are going to keep the bike,get a manual------good luck

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