My Yanmar (4JH3-HTE) has been faultless albeit a little smokey of late.

I have never really run it too hard and probably even too gentle for a diesel. So today I decided to run it at almost WOT (3500RPM out of 4000) to see if it was a carbon build up issue. Slowly but surely the smoke reduced to almost nothing. BUT..... when I reduced the power back towards idle, the trusty diesel just stoped.

It would run on successive attempts at idle and on increase of power, but every time the power lever was bought back to idle the engine just stopped. It had also been in the past an instant starter. Now it kicks over after about 3 seconds of cranking.

I am hoping all I have done is somehow thrown out the timing. What are the your thoughts