I am an addict. There, I said it. H2

[baz]

And late BSA singles

BSA had to go to shell bearings to be able to rev to 8250 rpm
Roller bearing big ends on the c15 b40 44 50 won't take those kind of revs

 

[concours]

Do shell bearings ever get used on a two stroke?
I've never seen it
You'd have to have a sump or oil tank
Plus an oil pump
And where would all the oil from the big end shells go?
It'd be burnt by the pistons as it was flung out with no regulation as the engine warmed up

No.
Shell bearings are designed for constant oiling. Two strokes rely on oil mist. Only roller/ball bearings survive.

 

[baz]

No.
Shell bearings are designed for constant oiling. Two strokes rely on oil mist. Only roller/ball bearings survive.

I assumed that was the reason

 

[TomU]

That make sense. Learn something new everyday LOL

 

[concours]

 

[mean gene]

I would expect to see ports enlarged when re assembled!

 

[concours]

I would expect to see ports enlarged when re assembled!

I am considering it....
Trying to find CAST pistons now.

 

[mean gene]

Try Don's Cycle Hallam PA did have some NOS parts 717-755-6002. I'm surprised your engine don't have Dykes top ring, most Yamaha's did!

 

[concours]

 

[MichaelB]

WOW!!!

 

[mean gene]

Ugly !

 

[concours]

WOW!!!

Ugly !

No worries now, I'll stitch it right up.

 

[concours]

Japanese made, CAST pistons in the mail.

 

[mean gene]

Never doubted you'd stitch it up!

 

[concours]

 

[bill]

View attachment 102633

nice glue gun you got there

 

[KiwiShane]

View attachment 102633

Insert spigot and weld ?
Nice piece of kit

 

[baz]

View attachment 102576View attachment 102577View attachment 102578View attachment 102579View attachment 102580View attachment 102581View attachment 102582

What caused this?

 

[concours]

Insert spigot and weld ?
Nice piece of kit

No spigot, bevel & weld. Better than new.

 

[KiwiShane]

View attachment 102633

Insert spigot and weld ?
Nice piece of kit

No spigot, bevel & weld. Better than new.

You can tell I'm a novice
I'm sure you will make a excellent job of it...