I have just purchased 44 and 50cc Echo short blocks. I measure the thread size as 5/16-24. What confuses me is that everything else on these engines has been in metric. Tried some metric thread checkers but the 5/16 fits best. What size thread are on these motors from Echo?

Maybe they are designed to attach to American equipment. I have come across quite a number of items that have this "feature".

If 5/16-24 fits best, use it.

Safe Flying!

That is the way I am leaning. Funny thing is that Echo themselves, nor any of the dealers I call can tell me anything regarding the size.

Hi Tim,
My 44cc Kioritz has a 8x1.25mm at the flywheel end. The other shaft is for the oil pump of course. It seems real strange the they would go to a 5/16x24 since the short block is ment to replace a bad saw motor. I see that you came through the storm ok. Let me know when you have those echo parts ready and I'll send you a money order.

Dave

If its like the koritz I have, echo chain saw engine, it is 5/16. Steve

Thanks Dave. The storm was just a summer drenching with some wind. All OK though. So I didn't get to work on anything but will start this week. Strange on the thread sizes.