rattlecan sound coming from stock 97cc

[DroptCK]

I have a wierd sound coming from this doodlebug I just got...it revs up nice, but when u let off the gas, it makes a sound similar to a spray paint rattle or as I describe it, it sounds like it detonating....please HELP!!!

 

[Erok000]

check your oil. make sure everything is all thight. Oil your clutch. Thats what id do first!

 

[bandit 40]

Did you put oil in it??? they dont come with any in it....if it was brand new.

 

[DroptCK]

I got it used, they guy I got it from ran Avgas in it, if anything it has too much oil, would that cause this? I thought it may be the valves.

 

[DroptCK]

And everything is tight, it makes the noise with and without the clutch mounted, by the way

 

[texasfabguy]

Check the heat shields on the muffler.

 

[bandit 40]

Check the heat shields on the muffler.

This was a problem on the one I had, the heat shield was vibrating on the muffler:thumbsup:

 

[DroptCK]

All of the heat shields are gone, it sounds like its coming from inside the motor. It doesn't do it when reving up at all, just on the way down the rpms before it returns to idle.

 

[gumpit]

Try new gas....

 

[DroptCK]

Forgot to say that too, I cleaned all the Avgas out completely. Running 89 now.

 

[DroptCK]

I'm gonna try to take the muffler off, Bandit. Maybe something inside of it, thanks

 

[texasfabguy]

Maybe a baffle inside of the muffler too.
If you are convinced it's in the motor try looking down the spark plug hole at the top of the piston,look for marks on it. If you don't find anything there pull the side cover off.

 

[bandit 40]

It may be time for an upgrade, you dont want that rod (if its knocking) to break:no:

 

[DroptCK]

I'm ready for an upgrade alright, I have an 8 HP Briggs with a TAV goin on it, just waitingfor the cash to get my TAV mounting plate, but need this motor to work for now.
I will try the muffler, as I already looked for signs of damage in the combustion chamber and took the side plate off and the springs were intact.

 

[duppyconqueror]

i have the same thing happening with my 6.5 clone. the rockers were loose but that didnt solve the problem check your rockers and rod.