sounds like a helicopter

[Thumbtack]

Yamaha 90 ETLJ is making new noise
kind of sounds like a helicopter or the noise from when you put a baseball card in the spokes of your bike. It doesn't do it at full throttle, it runs real good at full throttle and doesn't make that noise. It has always been a quite engine and this is a new noise. Thise noise is heard mainly after coming off of full throttle and when i'm just starting to take off. I'm afraid it is something like a piston slapping against a wall.
I'm just wondering if anyone has experienced this or if anyone knows a simple way to fix it like timing or something? If it is something bad and internal, how would it be fixable?

 

[JUSTINTIME]

Re: sounds like a helicopter

take it back to a dealer

 

[Thumbtack]

Re: sounds like a helicopter

Just called the dealer, said they won't be able to even look at it for weeks. Maybe i'll just double check the timing and all that to make sure its not too far advanced. Other than that i don't know what would cause this noise.

 

[zzzzz]

Re: sounds like a helicopter

could even be a reed cracked...sounds like a dealer job

 

[MikDee]

Re: sounds like a helicopter

Wow, Cool, wish mine sounded like a helicopter

Seriously, it maybe a bad reed, like the previous poster said.

 

[Thumbtack]

Re: sounds like a helicopter

haha thanks, ok i will take a look at the reeds. I've done reeds before on mercs. I probably should look to see if fuel is spitting back out the carb but even if it isn't i'll still take a look. It does stall at a low idle so that can also be the reed.
thanks

 

[Thumbtack]

Re: sounds like a helicopter

ok so i started it up and didn't see any fuel spitting out of the carbs. I did see the bottom carb was getting too much fuel as the fuel was pouring out of the main nozzle in the center of the carb. Also when i shut the engine off smoke billows out of that carb and only that carb. I took off the carb and looked at the reeds and they seem fine, none are missing and they all look closed all the way. I will double check the reeds behind the other carbs though and i will rebuild this carb although i know the carb has nothing to do with the noise.

 

[Ray Neudecker]

Re: sounds like a helicopter

The needle is sticking in the carb. Don't be suprised if you get the carbs right and the noise goes away.

 

[Thumbtack]

Re: sounds like a helicopter

really? ok i will give it a shot then