Yanmar 2GM vs 1GM Shaft sizes

[eebygum]

Is a yanmar 2GM shaft size the same as the 1GM; and if so what is it !! 1" or 1.25" ?

Any help appreciated as the boat is still in the water and I cannot take out to check or get down for a few days.

Many Thanks

 

[sailorman]

a 2GM with an s/s shaft would only req 1"

 

[Spyro]

[ QUOTE ]
Is a yanmar 2GM shaft size the same as the 1GM; and if so what is it !! 1" or 1.25" ?

Any help appreciated as the boat is still in the water and I cannot take out to check or get down for a few days.

Many Thanks

[/ QUOTE ]
You can still measure the shaft inside the boat it will be the same size as the bit that gets wet. They may be different sizes on a 2gm depending on which gear boxes is fitted

 

[PeteCooper]

My 1GM is a 1" shaft.

 

[Cloven]

My current 2GM has a 25mm shaft - previous boat had a 1GM with a 7/8" shaft.

 

[Tranona]

Most likely to be a 1 inch, but check carefully as it could be metric 25mm. Some 1GM installations have 7/8 or 22mm shafts and some 2GMs have 1 1/4 or 30mm - and 1 1/8 or 28mm are not unknown!

 

[srp]

On both the 1gm10's I've installed I used a 3/4" shaft. The coupling provided by Yanmar with the engine was (annoyingly) 20mm, and Barrus, the importers, can't or won't supply a 3/4" one. I had to bore and sleeve the first one, the second didn't matter as I used an Aquadrive, which comes with any size coupling you want.
I think a phone call to Barrus to find out what they supply with the engine would be wise, (as Tranona indicates, it could be metric or imperial), so you can specify a shaft size to match.

 

[charles_reed]

It varies, dependant on the unsupported free length of prop shaft.

Mine is 25mm, but I've also seen 1" (25.4mm) and 32mm on the 2GM.