The rev counter for my Yanmar 4jh3-hte on my gauge is fluctuating the higher the revs the less fluctuation.
I don't believe the tachometer is working correctly .
Where is the tachometer sensor on the engine? or where does the rev counter get its input from and how can I check this.?
e.g the rev counter will show 1200 rpm and then jump to 1400rpm with no increase in engine revs or bounce between 1500 rpm and 1600rpm
s/v Dusk # 378