Strange diesel behavior

[Sailboatvirg]

Here's a question for you diesel heads, A Yanmar diesel sputters and dies whenever put in forward gear, have checked all the obvious, ie; air filter, injectors, prop shaft, air in line, the easy stuff, now why does this diesel run smoothly and without sputtering when put in reverse? what am I missing? Help!!!

 

[Rich Stidger]

This is a stretch, but is there any chance that you could have something tangled in your prop? The reverse gear ratio is lower so perhaps the engine can overcome the tangle in reverse but stalls at the higher ration in forward?

 

[Benny17441]

Yes, check that the shaft and prop are running freely. Try turning the shaft by hand in both directions, if it does not check the prop and cutlass bearing. If it does turn freely then check the gearbox; make sure the linkage is properly adjusted for fully engaging forward gear.

 

[Sailboatvirg]

Thanks for the suggestions, will get under the boat (Brrrrr! waters cold right now).

 

[jssailem]

GoPro on a stick. Only issue is the image will be upside down.

 

[uncledom]

JS there is an option on most GoPros to flip the image.

 

[HMT2]

Had a somewhat similar problem with my Yanmar, it ended up being a blocked air vent to the fuel tank.

 

[jssailem]

Thanks UncleDom, It took me a while, but I did figure it out. Had me doing some contortionist moves trying to flip the iPhone fast and imagine I was flying upside down before I stopped and read the manual. Got a workout, but my head was sore.

 

[kloudie1]

I think Rich has it.. A too low idle speed .. then the engine can tolerate the extra load because of the lower (numerically higher) gear ratio.. but in forward, it dies. Check fuel filters (not mentioned) and set the idle speed with a photo tachometer.