Yanmar 1GM vs. 1GM10 - how to tell apart
I'm going to check a used yanmar 1gm(10) tomorrow, that i might buy (and install in my Albin Vega 27' sailboat)
Does anybody know how to tell the diffrence (seller can't locate engine type plate)
Rasmus Lind Hardt
The 7.5hp 1GM does not have an external oil filter. Inadequate for a Vega - and 9hp 1GM10 is marginal as well. Check gearbox ratios as you need at least the 2.6 or better the 3.1 to swing a large enough prop.
A good way also is to check the top of the valves, if they have a hat like disc perched ontop of the valve the engine is the later 1gm10 or 2gm20, if its not there is just a 1gm or 2gm
Ps this can change if the engine has had the head/valve gear changed in the past
Thank you both for the advice.
I was only after the 1GM10 (allso considerd 7.5hp inadequate) This is why I need to be able to tell the 2 types apart.
I know the 1GM10 is not a powerfull engine for a Vega (But the wife doesn't sail, therefore the cheaper engine is the better engine - and this one is for sale for 5000 danish kroner = £600)
P.s. Does anybody know if 1GM10's are old enogh to have corrosive problems (it's raw water cooled) This speciment sails in relative low salinty in a Danish fjord.
There is one acknowledged weakness on all the later GM range 1/2/3.
Originally Posted by Tailwind Vega
Because the increased power was obtained by boring the engines they have a habit of developing a leak from water jacket way into the block at the cylinder-head joint.
They continue to run, but gradually lose power as (especially in the case of the raw-water cooled) the bores and rings corrode. I have had bitter experience of the phenomenon.
In view of that weakness and the lack of power output from the 1GM10, for your size boat, I would counsel against fitting one - you'd probably end up a very disappointed Fjordander.
For what it's worth, my 1GM10 seems to push Jumblie along quite nicely - 26', 3 tons, long keel. It's definitely an auxiliary, though, used when there is no wind and not as a substitute for beating to windward (or flexible planning!).
Originally Posted by charles_reed
Also check out the 2 oil pipes at the front they can corrode
relatively easy fix though
wheres the oil filter on the early one then?
Originally Posted by Niander
I'm not sure but it may be more of a strainer that you take out and clean like the older YSE/B/M had
The engin type is cast on the top of the main block just behing and to the right of the cylinder head when viewed from the alternator end.
There is also a metal plack on the left side with the infomation on it.
Olso the 1GM dose have an external oil filter. I have one.
Dont forget though the later 2gm20 end 3gm30 engines have liners.