1GM10 Head Gasket

[geofflena]

Hi - just registered here. Sail a 22' yacht Lena out of Uphill, Weston s Mare - UK.

Since I currently have the head off my 93 1GM10 - I thought I would mention that the Yanmar drawings of the head gasket replacement in the 2002 workshop manual are wrong !

They show the gasket as Tappet chamber at the TOP - gasket mark UP - and FLYWHEEL side left - gear side right. They have done the same on all the two and three cylinder drawings as well.
This drawing is side by side with the torque setting drawing - which is correct - ie tappet chamber bottom, then flywheel is left and gearcase right.

Considering the head gasket is an expensive and important item this is not good. Makes one wonder what else is wrong !

Also - as mentioned elsewhere - the new gasket( genuine) has an A stamped on it - not TOP as they say ( whats TOP in Janpanese ? )

The plain metal face - on which is stamped 'A' and also a 'patent no' in the corner - is the top surface as laid on the block. This plain metal surface mates to the head face.

The underside is the graphite type material - with the exposed oval holes showing.

The plain metal side only has one small round hole and one oval hole for water. The metal blocks off the other holes.

The small hole mates to the oval casting hole next to the temp sender in the head.

Now lets forget Yanmar heads and get on with Christmas.

Geoff - Bristol UK
a few details and pics below, plus pre-combustion chamber bits.

lena - Invader 22 - sailing Lena -