Hi I'm new to the forum , I have just purchased my first beta it's a rev 3 2003 and there is a rattle coming from the engine ? Could it be a piston , bearing or barely needs re - chroming ? If anyone could help it would be appreciated thank you .

Hi without hearing the noise or rattle it would be hard to say,but if u still got plenty of power,why not just remove the barrell and head as one,that way you only to renew the base gasket,bit of a tight squeeze but can be done in situ,to check the state of the piston, rings,small end bearings i did that to mine,and found a lot of play in the little end bearing,

Edited June 11, 201313 yr by bilks

Could be low octane gas. My 05 REV3 sounds like someone’s tapping on the cylinder with a hammer if I run sh*t gas. Just a thought.

Edited June 11, 201313 yr by crazy_dave

Ya my 07 was a bit fuel fussy, I ran some ring free through it to decarbon and it was much much better

But if its rattling at idle then is piston skirt wear or shrinkage from overheat

And I have heard of crank bearings going on them but I would think that would produce a growl and deep knock from down low in the motor

Thanks a lot will strip her down today and have a look . The carbs on them are a nightmare to either not enough fuel coming through or too much and it comes out of the overflow .