View Full Version : Yanmar 3GM30F

01-10-2009, 01:04 AM
"I have a Yanmar 3GM30F recently re built, still hard to start when cold, easy start at the touch of the button when hot. Reading others comments on this site has helped.
Recently repacked the stern gland, not over tightened and shaft turns easily by hand.
Problem. Motor stalls or chokes when put in reverse, feels like its overloaded, no problem in forward gear, goes well.I intend to unpack the stern gland and put back as was to see if this caused the problem, any advice would be welcome. thanks Bob.}}"

01-10-2009, 11:36 AM
Remove the injectors and check the bumper clearance. It explains how in the Yanmar work shop manual. A must have when you own a Yanmar Diesel and you want to trouble shoot and do your own checks. You may have a short con rod. Also double check your valve lash. It should be .008 all valves cold. After this unit was rebuilt did you take it for a good run. This engine is designed to run at 3000 rpm. max is 3600 rpm under load.