GZ 250 Forums - Valve Issue?

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Hi All,

I have a 2006 gz250 with 4500 miles that has a metallic tapping noise. I used a mechanic's stethoscope and it seems to be coming from the exhaust valves. I adjusted the valves to spec but the sound is unchanged.

Everything else about the bike is great, it has good acceleration, starts up fine, and has a solid idle. I have read through this forum trying other suggestions, even checked the cam chain tensioner. I thought it could be a loose cam chain slapping the engine wall, but no.

Is there anything else you guys can think of checking before I try to pull the head and take a peek inside? Thank you in advance!

If the valves are set correctly and you can still hear them a bit that is okay. When you can't hear them they are too tight. Just ride and enjoy a little mechanical music.

Thanks Water Warrior. The previous owner didn't tune the bike, and mentioned he often used the choke to keep it idling, never touched the idle screw on the carb. :(

I got it for a deal, but the sound does not inspire confidence when riding. You don't think this sound could be an early warning of a major issue? I understand gz250's sound like sewing machines, but this has a clear metal on metal plinking each rotation, all temperatures, gears, and acceleration.

In short, is there anyways to reduce the noise rather than live with it? I already used a bit of lucas oil stabilizer and this did make the tap a little less distinct.

Quote:

Originally Posted by gzed (Post 84937)

Lol, maybe a noisy sewing machine. You have to keep in mind you have an engine right under you with nothing to absorb sound like a car with a firewall and sound deadening materials.
Just be sure the Lucas oil stabilizer is compatible with a wet clutch. If not you may experience clutch slippage.

If you are in doubt about the engine noise seek out some one who knows engines and their noises. Question for you. When you listened with a stethescope you will hear all sorts of frightening sounds. Are you worried about those sounds or just regular sounds with your ears.

I'm with Water Warrior on this one.
Set valve lash just right. It's a PITA but worth it.

Quote:

Originally Posted by Water Warrior 2 (Post 84938)

Question for you. When you listened with a stethescope you will hear all sorts of frightening sounds. Are you worried about those sounds or just regular sounds with your ears.

Nothing crazy with the stethoscope, I just used it to try to locate where the sound was coming from. But normal tapping, no grinding or squealing.

Just worried about the sounds with my ears, as most motorcycles I have seen don't have such a clear metal on metal noise from the head. The kind you might hear when a valve is lightly smacking the piston.

Appreciate the advice, will keep an eye on it.

Quote:

Originally Posted by gzed (Post 84956)

Nothing crazy with the stethoscope, I just used it to try to locate where the sound was coming from. But normal tapping, no grinding or squealing.

Just worried about the sounds with my ears, as most motorcycles I have seen don't have such a clear metal on metal noise from the head. The kind you might hear when a valves is smacking the piston lightly.

Appreciate the advice, will keep an eye on it.

Don't ask me how I know this but...I really had a hard time getting to TDC on the compression stroke (this was on my Suzuki Marauder VZ800). Somehow, I think I was in the exhaust stroke and it was pretty darn noisy until I got it right. I would recheck to make sure you have the right line up for TDC before you use the feeler gauges.

For the GZ, it was a little slappier after I did the valve adjustment, but nothing that worried me.