XR600R engine noise

[mlkdvm]

I recently got a '91 xr600r. The previous owner had installed a new piston and I'm not sure what else. The engine starts and runs o.k., and seems to have good power. The compression, as measured by the feel of the kick starter, seems lower than that of a '93 I used have.

There is an intermittent "clicking" sound coming from high up in the engine. Sometimes I hear it 10 times a minute, and then sometimes I won't hear it for 5 or more minutes. My guesses as to the source of the noise are the decompressor or cam chain tensioner. I know trying to diagnose a sound that you have never heard is difficult, but does anyone have any ideas?

[michaeln]

I have a similar noise in the top end of my XR650L (33K miles). I have asked around and the concensus of opinion was that it is a worn cam chain.

[mlkdvm]

So is that the sound of impending doom? How long have you been riding yours with taht noise?

[michaeln]

I've ridden it probably 3 or 4 thousand miles since the noise started. It doesn't seem to have gotten any worse.

[Miker]

tick....tick....tick.....

[XR6's_rule]

If its a constant metallic rattle that is at its worst when the bike is first started, i'd say it'd be a worn cam chain. But if you're only hearing a clicking noise a few times a minute, and your idle speed is low, it's probably the auto decompressor kicking in. To stop this, adjust your idle speed a touch higher and it should stop. Good luck!

Mark.

[Smokin XR 600]

I had the same problem with my 89 xr 600r. The guy I bought if from said that the local bike dealer said that it was a cam chain...ok, so I buy it and take it to the mechanic, and he gets into it and says that the cam chain tensioner was wore out, but the noise we heard was rod chatter. I sure do hope this is not the case for you, because it is a quite expensive fix, $1400.00 worth the fix for me. Good luck.

[mgs781]

How on earth does it cost $1400 to replace a rod and piston? If your description is acurate, you are talking about maybe $400 in parts and a few hours to install.

MGS

[Miker]

How on earth does it cost $1400 to replace a rod and piston? If your description is acurate, you are talking about maybe $400 in parts and a few hours to install.

MGS

You show me a dealer that will do that work for 400.00 parts and 2 hours labor. I will bet the oem piston and rings and rod were close to 500.00 Add in gaskets, berings, cam chain, bla bla bla and it would be easy to get to 1400.00. 2 hours? Try 8.

[brs1972]

$1000 easy. An XR650L and other thumpers have semi-permanent connecting rods. It's a $620 crank/rod assembly. Add $60 X 2 for bearings, $160 for piston/rings, $50 for gaskets, $60 for the cam chain. There you go.

I'm currently looking for a bolt-on conn. rod for my '88 NX650. The engine is nearly identical to the XR650L's. Let me know if you have something.

[mgs781]

You show me a dealer that will do that work for 400.00 parts and 2 hours labor. I will bet the oem piston and rings and rod were close to 500.00 Add in gaskets, berings, cam chain, bla bla bla and it would be easy to get to 1400.00. 2 hours? Try 8.

Well then, I am sure glad I do all my own work. If I had to go to the dealer for something like this, I could not afford the bike.

In all honesty, I thought he said it was a top end problem. In which case I would not expect the job to run more than $600-700. It took me 30 minutes to remove the head on my L this weekend and that is being very careful. A few hours only means more than one, I think a good wrench can do the job in 4. Bottom end, that is a different story. I think dealers get away with murder when they have to open up an engine.

MGS