What is the size of the large pushrod tube 'O' ring, the one that fits into the crankcase, is it 25mm or 1 inch, i canna remember, it is a 1800 motor

Thanks Andy

as one inch = 25.4mm ther would be little difference and with production tolerances it shouldn't matter

so are they 25.4mm, i need to get replacements

Andy

Make sure you get the German ones.... the cheaper varieties tend to go hard and leak prematurely.

The inner ones (case side) are black & smaller.The outer ones (head side) are either red,green or yellow & are larger of the two.Try not to pinch them when installing them.Use curil K2 good German goop.

Hi

I always used rubber grease on them as they are supposed to move in & out as the motor expands and I polished the bores that they slide in with 1200 wet & dry.

1302Steve