M35 universal hunts and stalls

[Duane1969]

My M35 universal diesel starts and runs but hunts at the idle speed 1000 RPM. When I increase the RPM everything is fine. If I decrease the RPM slowly everything is fine if i pull the throttle back to the stop quickly the engine goes below the idle point and stalls. At this point it will start right up and idle. When powering with the boat i can reach max RPM no problem. Iasume it is not starving for fuel on the high end. If i pull the throttle from full on to the idle stop quickly the engine will stall. I have a new fuel tank one year old, lift pump and internal filter are good have changed canister filter but still stalls when you pull the throttle back quickly. If pulled back slowly it won’t stall. Could this be a governor problem? Help

[Shelter]

I have an M-40, great engine to have btw.

These throttle cable lever (pump side) are an odd design, if not tightened the throttle might fall below the minimum threshold. I would look in to first (if fuel system is actually clean) first.

if you need more PM me

[Stu Jackson]

Originally Posted by Duane1969

...............but still stalls when you pull the throttle back quickly. If pulled back slowly it won’t stall. Could this be a governor problem? Help

Forget the governor.


You just need to adjust the stop on the throttle, usually top starboard side of your engine.


Your throttle cable could be aging, too.


While not specific to your problem, you might be interested in this, too, because I had that same issue on my M25, until I fixed this one:





Fuel Starvation and The Obscure Check Ball Valve
https://c34.org/bbs/index.php/topic,10681.0.html
and
https://forums.sailboatowners.com/th...l%20Starvation

[goboatingnow]

classic governor weak spring issue , had it on a TAMD61 , exactly same issues as you , including the stall

mine would disappear after a 10 minutes of increased revs but could reappear if the engine was idled for a while

[sinnerman]

I had the same issue on my M25. When bringing the throttle back to idle, the engine RPM's would drop down to 800 or less and the engine would stumble then stall (die), usually at the worst moment.

The spec idle speed for the M25 is 1000 RPM. Some set it to 850, but this is too low.

My issue was caused (as others have stated) by a loose throttle lever. This lever sits on top of the injector pump and inputs the throttle (speed) command to the injector pump/governor springs. Being loose allows the lever to "cock" slightly , throwing off the idle stop adjustment.

Tightening the nut on top (item 10 in the LINK below) fixed the problem:

LINK: TOAD Marine Supply

Note that there is a friction washer under the throttle lever (item 11), so you are not torqueing the nut completely down. You are just tightening it enough to remove any excess play in the shaft.

cheers.