Engine cutting out when in gear

[RodChapman]

Just had my yanmar 2gm looked at because it was really struggling to start in the cold weather. Had a new alternator and water pump installed, just been back to start her up and it's starting alright if I start in a high throttle but if I then lower the throttle or put it into gear the engine cuts out. Mechanic mentioned the kill cord being dodgy and I don't know how old the fuel filter is, is it likely the problem could be do to with either of those? Also bought the boat with the reverse gear disabled, mechanic fixed that too but maybe could have affected things? 

Edited March 15, 2021 by RodChapman

[Alan de Enfield]

5 minutes ago, RodChapman said:

Just had my yanmar 2gm looked at because it was really struggling to start in the cold weather. Had a new alternator and water pump installed, just been back to start her up and it's starting alright if I start in a high throttle but if I then lower the throttle or put it into gear the engine cuts out. Mechanic mentioned the kill switch being dodgy and I don't know how old the fuel filter is, is it likely the problem could be do to with either of those? Also bought the boat with the reverse gear disabled, mechanic fixed that too but maybe could have affected things? 

 

They are not ideal engines for a NB as they are designed to be run at high revs continuously , the 2GM is only 13hp at 3400rpm - what boat type is it fitted in ?

 

The 2GM is designed to be raw water cooled, how is yours cooled ?

 

I have the manual for it if its any help to you.

 

The troubleshooting for 'stalling' is attached :

 

 

[RodChapman]

Have contacted my mechanic, he suggests a fuel filter clog so I'm going to replace that and the oil filter, will update. 

[Tony Brooks]

First off I am not sure what a kill cord is doing on an inboard diesel unless he means the stop cable. I notice it changed to switch in Alan's quote of your original post. If a stop switch is making or breaking contact due to vibration, depending upon if its energise to run or energise to stop then that could be the issue. More vibration as the engine slows.

 

Personally I would expect a blocked filter to cause the opposite - failure to reach high revs and high powers but run OK on idle.

 

Try it with the fuel filler cap ff in case the fuel tank breather is blocked. After a period of high speed running a blocked breather would allow a vacuum to build up in the tank so at low seed the fuel pump could not suck enough fuel to keep the engine running (assuming a mechanical pump).

 

Anyway changing the filters will do no harm.

Edited March 16, 2021 by Tony Brooks