tepping noise yamaha 75

[gile]

i have some tapping noise from the engine i try to hear it by attach screwdriver to the engine
and it looks like the tapping come from the upper
part of the block, the engine work fine,the noise sound like valves tapping in a car but of course there is no valves in this yamaha two stroke engine , what could it be ?

[boats.net]

If it's coming from cylinder end of block it could be piston slap, stuck rings or excessive clearence between cylinder and piston check compression. Otherwise it would be a rod or main bearing.

[chompin]

are you mixing enough oil, is the problem started after some abnormal event .
try checking if there was an oil problem .
i had some tapping noise in a similar engine
and it's was solved by changing the oil mix

[chompin]

what is a piston slap ?

[boats.net]

It's when there is too much clearance between cylinder and piston from worn cylinder or stuck piston rings and it will make a ratting noise.