Yanmar 3GM30 Valve Clearance

[Belize 43 crew]

I have a Yanmar 3GM30FC and need the valve clearances.
Forums say 0.2 +/- 0.03 and 0.2 +/-0.08, which is right?

[shakey doug]

G'day,
3GM30FC valve clearance as per official Yanmar manual both inlet & exh cold 0.2mm or 0.079in [ 8thou ].

[Belize 43 crew]

Thanks, 0.2 mm. is there a + / - leeway on this?

[shakey doug]

Set them so you can feel drag on you gauge this is close enough it is SUPER critical every techs feel is different.

[Ex-Calif]

Hold the adjust nut while you tighten the lock nut with the feeler gauge in place. After tightening lock nut there should be slight drag felt while pulling the feeler gauge out. Too tight - repeat. Too loose - repeat.

Dougs right - everyone's feel is different but it isn't "that" critical. You should feel the gauge drag, though.

[Dragon Lady]

Do they change much?
The drag should only be light i.e. you should be able to slide the gauge easily with two fingers.

[ncbrew]

Originally Posted by shakey doug

G'day,
3GM30FC valve clearance as per official Yanmar manual both inlet & exh cold 0.2mm or 0.079in [ 8thou ].

which valve is the intake

[RaymondR]

You used to be able to buy go-no go gauges that experienced mechanics used to adjust valve clearance whilst the engine was running., it was considered to be the superior technique.

It is more important to have too much clearance than to have too little.

[Wotname]

Originally Posted by ncbrew

which valve is the intake

See red arrows.