Engine whistle

[Adamastor]

Hi there!

When I am revving my GN250 (equal to GZ250) engine, I hear a whistle sound (different sound according to revs). Never paid too much attention to it, but I wonder if this could be any air leak that might do something wrong to the engine... or could it be any chain inside the engine?
Is there any chain tensioner maintenance to be done? Are there any tutorials on the web?


Regards,

Sergio

[jonathan180iq]

Is this your first motorcycle?
If it is, you have to understand that there are some noises associated with riding a bike that you just won't be used to like chain rattles, some "tick,tick,ticks" and lots of windy "WHIIIIIRRRRRRs". Start worrying when the bike starts making DIFFERENT sounds than normal or when it starts acting funny.

[Water Warrior 2]

Bike noises also change with the area you ride in. Remember sounds will be reflected back from buildings, high curbs, different road surfaces and other traffic on ocassion. Hearing protection(ear plugs)will help cut down on the noise and generally improve the riding experience.

[bonehead]

Sounds to me like the turbocharger is engaging....LOL

[Adamastor]

I have lots of experience on old scooters (vespa, lambretta) and I know this is no aerodynamic noise because you can listen to it standing still...
Maybe it's from the muffler... not sure.. Just hope it's not from the carburator or the manifold... an air leak could lead to disaster... :| I was just wondering if this could be something known among GZ250 and GN250 users...

[jonathan180iq]

A whistle, if it's high pitched and steady, has to be from a loosened air box hose somewhere. There are a couple of vaccum hoses that connect the air box to the carb and there is one fat "S" tube that connects the air box to the crankcase. Check those.

After that, drop down and listen to the muffler. THere is a small hole in the bottom that is used to allow moisture to escape the exhaust system. It's possible, although I've never experienced it, that this is causing a whistling sound.

The only other thing that I can think of is removing the side panels and checking that the air filter itself is securely screwed in. There is a rubber seal on the back of that filter and if it has some moisture on it, I can see how it might make a whistling sound.

[Adamastor]

Thanks, Jonathan, those are very good spots to look for... My muffler has seen better days, but I believe the whistle doesn't come from there... I'll check the hoses first :)

Sergio

A whistle, if it's high pitched and steady, has to be from a loosened air box hose somewhere. There are a couple of vaccum hoses that connect the air box to the carb and there is one fat "S" tube that connects the air box to the crankcase. Check those.

After that, drop down and listen to the muffler. THere is a small hole in the bottom that is used to allow moisture to escape the exhaust system. It's possible, although I've never experienced it, that this is causing a whistling sound.

The only other thing that I can think of is removing the side panels and checking that the air filter itself is securely screwed in. There is a rubber seal on the back of that filter and if it has some moisture on it, I can see how it might make a whistling sound.