Yanmar 2QM20 - Why Is One Of The Head Studs So Long?

[charliehows]

Checking my tappets yesterday, thought i'd check the head nuts for tightness - looking at the front (pulley, waterpump etc end) of the eng. the nearest right hand head stud is a good inch longer than it needs to be for the nut - At first i was worried someone had put the studs back in the wrong place but looking at the manual it is shown as such very clearly in the detail drawings. Anyone know why this stud is so long? The same stud on the 3qm30 is also like this...

[colemj]

It is because when the list of boat projects becomes so short that you are down to checking the various lengths of your head studs, then they throw that in there just to mind-f*$k you enough to keep you from relaxing with a drink and fully enjoying your boat.

Be thankful you don't have a catamaran with two engines - they make the longer stud different on each in those.

Mark

[Hoofsmit]

Mark

That tickled me, so true.

[cal40john]

Thinking ahead for a mount for adding something driven by a fan belt?

Place to attach an eye for an engine pulling bridle?

[bony]

".....Place to attach an eye for an engine pulling bridle?"

I"ll second that. A lifting eye bracket is normally attached to that stud, so it needs to be long enough to accomodate 2 nuts and washers and the 1/4" thickness of the bracket. There is one on my 2qm15.

bony.

[charliehows]

yeah that makes sense - theres already a lifting eye on the other end of the engine on the other side so one on this end would balance pretty well. Thanks.