yanmar 2gm f20

[frank]

Does anyone know what the max RPM is for the yanmar 2gmf20. My 87 model only goes to 3000. I thought something was wrong w/ it? But a friend of mine's hunter w/ the same motor is the same way. Is that normal for these older model 2 cylinder deisel?

 

[BobM]

I think so

The max RPM for my 2QM15 is ~3000 and it cruises at 2800.

 

[capn jim]

max rpm

max rpm for 2QM series is 3000, 2Gm series is 3450 i think. it has a shorter stroke than the Qm's

 

[saltygator]

I can get 3200

but it sounds like it is coming apart. I prefer to run it around 2800.

 

[Landsend]

If you are talking 3K without load

then you have a clogged exhaust elbow.

 

[Richard]

2GM20F max. RPM

Max rpm is 3600, max. cruising rpm is 2900

 

[frank]

clogged mixing elbow

Thanks all, I'm leaning towards the clogged mixing elbow. Yes 3k no load.

 

[Steve Dion]

2GM/3GM

Frank:

The 2GM/3GM is rated at 3600 RPM. You engine should rev to approx. this RPM when your transmission is engaged.

You did not mention how many RPM's you can achieve when you are turning your prop. Did you engine ever do better than this?

It is easy enough to r/r the mixing elbow. This may not be the problem if you are in fresh water. This is much more common in salt water.

After checking the elbow, be sure to have your govenor checked too. Be sure that you fuel system is clean from the fuel pick up in the tank all the way through to the low pressure side of your fuel system.

 

[Frank]

RPM

Thanks Steve Dion, its in salt to brackish water. and it does not matter if its in gear under a load or in neutral still only about 2900-3000 max rpm.