Small End Bearings Gap

[Bilko]

There's a gap of approx 3mm here. Is this ok without shimming?

[MarkH]

You need the 16x20x22mm bearing

[Bilko]

Ok thanks.

I rang PM as I had got the crank from them, but the chap I spoke to said it's to do with the piston type supplied. I've measured the gap in the piston and it's almost 24mm. So would I still need to shim the piston?

[J1MS]

Is it a Yamaha Blaster piston..??

[Bilko]

No Jims.

It's for the RB250 Not sure of piston type.

[J1MS]

Ive seen a couple of RB250 barrels using single ring Bultaco pistons...

[Bilko]

2 rings on mine.

How embarrassing not knowing the piston.

[andylaw7]

bilko had exactly same thing on my ts1 (still in current engine )and i was told by af it dont matter as long as the big end is shimmed after all where is it going to go .my concern was about uneven wear but was told not to worry about it ,tis the first time ive ever had a piston like this .

andy

[Bilko]

Would it not cause uneven wear on the small end bearings as theres quite a bit of space for them to move sideways?

[red]

I'm sure between us we could find some way to fill the gap