Long story short- I had some rusted valves so I had a head
shop install new yanmar exhaust
valves on two cylinders on my Yanmar
3GMD. Put the engine
back together (did do valve clearance adjustment). Engine
went together ok and turned by hand without any interferences (both in compression
and decompression by using levers). However when I rotate the engine using the starter in the decompression mode (using decompression levers), two of the levers seem to vibrate a lot. I do not remember this vibration prior to doing the head
So question is should the levers vibrate some when in the decompression mode? I am thinking the levers may not move the valve down as far as it is moved by the rocker arm, and maybe that is where the vibration is coming from. Also, after taking the engine apart, I see the clearance between the pistion and head is very little (0.7mm) so if the valve sticks down too much, the piston would hit it- I hope that is not what is happening on my engine when in decompression. When in compression
engine rotates fine with no interferences and it does have compression. I have not tried to start the engine yet.
Insight to the decompression levers and the vibration on the levers I am seeing would be appreciated.