Siezed montesa 348

[Dennisday]

I recouvertes a 348 1976 un siezed th cylindre etc but when it gets to the bottom of the stroke it blocks i suspect big ends but there was no play when I had the cylindre off any comments please

 

[johnnyboy]

Take it to a mechanic.......

 

[scooter paul]

I recouvertes a 348 1976 un siezed th cylindre etc but when it gets to the bottom of the stroke it blocks i suspect big ends but there was no play when I had the cylindre off any comments please

Could be a ring of rust still in the bore or maybe a piton ring is catching in the intake port. If it still sticks with the cylinder off it could be one of the coils in the flywheel is catching the flywheel as it rotates.

 

[streethawkonr1]

Could be a ring of rust still in the bore or maybe a piton ring is catching in the intake port. If it still sticks with the cylinder off it could be one of the coils in the flywheel is catching the flywheel as it rotates.

Could have a bent crack, happens a lot with trials bikes and water.

 

[DrFarkoff]

I recouvertes a 348 1976 un siezed th cylindre etc but when it gets to the bottom of the stroke it blocks i suspect big ends but there was no play when I had the cylindre off any comments please

Can it make a full rotation with the cylinder off?

Does the piston hit the crank at the bottom of the stroke with no cylinder

Is there something in the crank area below the cylinder preventing the crank turning

 

[dean0n0]

As above, did it spin freely with the barrel off?
Have you changed the piston and is it the correct one? Long skirt hitting the crank.
Are there balance weights in the crank flywheels? I've had one come loose and wedge the conrod.