2GMF

[John]

The survey on a 1986 28.5 I'm considering lists the engine as a Yanmar 2GMF rated at 13 HP. I can't find this engine listed in the Yanmar specs on the web. What I find is a 2GM20F rated at 13.4KW (18.2HP). Can anyone tell me if this is the same engine?

 

[Stephen Ostrander]

pretty sure

My '86 28.5 had the same engine. The 2GM20F ("F" stands for freshwater cooled) is rated at 18hp peak @ 3400 rpm, I believe. BTW, this is a very dependable engine. Usually the only complaint is that it's twin cylinders vibrate more than the 3 cylinder 3GM30.You should have more than enough hp to reach hull speed and power thru wind and chop.

 

[Eric]

Engine h.p.

I beieve that engine is rated at 16 h.p.. Later versions were 18 h.p.. It is listed on the engine plate. Either way, it is more than sufficient for a 28.5.

 

[Sam Lust]

Mystery

The 2GM and 2GMF are rated at 13hp at 3400 RPM, 15 HP at 3600 RPM for 1 hour. (No one's ever told me what happens after 1 hour. Maybe it turns into a Renault?) The GM10, 20, and 30 series have a larger piston bore and produce slightly more power through the range.

 

[Jim McCue]

I have same (2GMF) 13 HP on my '86. Works fine never missed a beat. Enough power. More important to keep your bottom clean of growth.