Scooterotica

Hello

I'm rebuilding a T5 motor for a mate. He seized it coming home from Mersea.
The flywheel bearing has been catching on the crank - there are witness marks on the crank cheek and some blueing of the bearing's outer race.
At first I thought the bearing had not been fitted correctly as it was protruding around 1mm from the casing. However, once I removed the bearing I measured the depth of the bore in the casing and it's around 14mm deep (the bearing is 15mm wide) so I'm pretty sure the bearing was fully home.
Perhaps the crank is at fault? I will certainly get it checked for balance and trueness etc.

Anybody got any ideas as to why this might of been happening?

Cheers

The T5 flywheel side bearing does sit proud by about a mil.

This is why so many T5 casings have had the bearing go through the casing at assembly.

Sound like crank out of true, also check the drive bearing

Hello Gaz

Thanks for your reply, tis appreciated. Only just picked this up.
The clearance must be pretty minimal in that area. I think the bearing bore is only 14mm deep to allow room for the oil feed hole.
The marks on the crank are not a full 360° which makes me think perhaps the crank web has a tiny wobble. Will get it checked.
Thanks again.

Was meaning to mention that I've now shimmed the main bearing as there was a 0.4mm gap between the outer race and the circlip.