Lots of valve noise.

I just revived an 88 xr 600r and it makes a lot of noise (pinging). I have heard that the RFVC engines are noisy, but don't know what that means exactly? Will adjusting the valve clearances fix it? Any other suggestions?

Definitly worth checking the valve lash....

Is it ticking or actually pinging under load :)

It pings loudly. I have adjusted the valve clearances (they actually weren't that off). What do you think could be the culprit?

Maybe it's running lean, Check the spark plug and make sure it's the right one :)

It's possible the pilot jet or main jet is gummed up making it run lean......

Check for air leak's, A engine running lean will ping.. :)

You have super in the tank, right :p

What are your thoughts on octane booster for an old bike? It has been years since I have torn into a bike. I just inherited this old xr. I actually got it up and running on Saturday. I was able to take it around the block a few times. It didn't run perfect. It seemed to lose power as I got about about mid throttle. The idle and low rpm was great for its vintage. Yesterday, it started very briefly and the motor stopped running when I gave it gas on the test run. What do you know about carbs and jetting? I live in CO and from what I have read, it seems like the bike was jetted properly. But I am definitely not a carburetor god. I definitely appreciate the help.

Like the other guys said, first of all, make sure you don't have an air leak around the intake boot. Remove the carb, and remove the pilot jet and main jet. Clean them. Then spray out the entire carb with B-12. Every single tiny hole must be clean and open. Make sure the float is adjusted to the correct height also, you need a shop manual.

Check and make sure you're not running a plug that is too hot. Start by installing the standard plug.

The bike should be jetted fairly rich, all big singles like to run rich, and it helps in Colorado to run it a tad bit rich even at altitude, to prevent overheating at low speeds. Jet it for the lowest altitude you'll be riding there, that way it won't be lean when you come down off the mountains. Not sloppy, sooty rich, but just rich enough to keep it cool at lower trail speeds. Works best when the airbox and exhaust are opened up as much as possible too.

You'll need a shop manual, worth the investment. Valve adjustments are tricky if you're not familiar with how to do it right. Too loose valves will make a ticking sound, too tight, and well, that's just very bad to have them too tight. Power is lost either way, too loose or too tight, they have to be just right.

Not knowing how much time is on the engine, it's hard to say if the cam chain is worn out or not, or, if the piston is covered up in carbon, causing the pinging. There's really no way to know without taking it down and looking at it.

The XR600 should not be a noisy engine, the XR650R, yes, is mechanically very noisy, but the old 600's should be nice and quiet.

Good luck with it!


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