Tools for Yanmar 1GM10

Capt. Clueless

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I have been reading my Clymers official shop manual for my Yanmar 1GM 10,and was looking for tool size guides.
If I took my full tool kit, I would need a secondary tender just to carry the weight of the 4 boxes, so looked to my manual to attempt to find out which tools to take to service it.
As I am miles from the boat, I cannot remember if these engines use imperial or metric nuts, and cannot find a rough guide as to what size spanners/sockets to take that should cover most of the servicing requirements. I'm just trying to avoid taking the whole lot, when one carefully selected box full will suffice. Any ideas on what are the most used sizes on these engines please? (I'm not a fan of Adjustables, but will take one also). Thanks.
 
As a 1GM10 owner I feel your pain!

They are definitely metric, and from experience, Yanmar have a great habit of using 2 or tree different sized nuts where one would suffice. Hopefully, someone very knowledgeable can come along and tell you exactly what sizes they use, but I take a small socket and spanner set with min 10mm and max 17mm size and I cannot recall using anything outside that range. That plus a multiheaded screwdriver and a pair of pliers normally does it.

Sorry I cannot be more precise
 
As a 1GM10 owner I feel your pain!

They are definitely metric, and from experience, Yanmar have a great habit of using 2 or tree different sized nuts where one would suffice. Hopefully, someone very knowledgeable can come along and tell you exactly what sizes they use, but I take a small socket and spanner set with min 10mm and max 17mm size and I cannot recall using anything outside that range. That plus a multiheaded screwdriver and a pair of pliers normally does it.

Sorry I cannot be more precise

Thats extremely useful. If you haven't had any issues outside of those sizes, that is a decent guide thanks.
 
I found that my set of 8mm to 18mm spanners did most things. My set has ring spanners one end and open ended of the same size on the other. Sometimes you need two spanners the same size so perhaps take additional 10, 12 & 13 open end.
I also needed about 4 different spanners to service the CAV fuel filter, BSW, BSP, metric and Mole grips because a previous owner had butchered stuff.
 
As with those above, metric spanner set, cross and flat screw drivers and a pair of pliers does 90% of the work on all Yanmars. I found the Clymer manuals less than useless, you would be better with the full workshop manual which can be downloaded on line (don't have the link to hand but if not, pm me).
 
As with those above, metric spanner set, cross and flat screw drivers and a pair of pliers does 90% of the work on all Yanmars. I found the Clymer manuals less than useless, you would be better with the full workshop manual which can be downloaded on line (don't have the link to hand but if not, pm me).

I'll have a quick look at the online version ta.
 
I'll have a quick look at the online version ta.

You don't need much to service the engine and the 8-18mm spanners and similar size sockets is more than enough. Be careful with using spanners on the heads as they are made of very soft metal and round easily. suggest you replace the water pump cover with a Speeseal as the bolts for that are particularly weak and one almost inaccessible.

The Clymer manual is OK for servicing, but is not "official". If you plan to do any serious work then the proper Yanmar manual for the GM series is well worth the investment.
 
6mm is very small.

So are the six screws around the water pump. 6mm rings a bell with me.

They do also have slots on, though, or at least mine did.

On the current boat I fitted a Speedseal which comes with special bolts with big chunky knurled heads.

Pete
 
6mm is very small. Hex is more likely 8mm, i.e. with 5mm thread. Even 4mm thread takes 7mm hex.

I think 6mm is right, they are tiny and very easy to drop in the bilge. If I remember, they are on the reverse side, so easier to remove the complete pump and work on it in comfort.
 
As others have said, a reasonably complete set of metric spanners (it uses 12, 13 and 14, for example) covers most things. There are some rather low torqued bolts which matter, and for those I bought a short Norbar 3/8" drive torque wrench,
 
6mm is very small. Hex is more likely 8mm, i.e. with 5mm thread. Even 4mm thread takes 7mm hex.

On my Yanmar 1GM10, I'm pretty sure I used a 6mm hex to remove the cover for the impeller. Removing the pump itself, I used a larger spanner. The pump was half obscured by the flywheel, so there wasn't room to use a socket

The triangular pump is between the 4/5 o'clock position, behind the flywheel. Here it's turning green. Click to enlarge.
IMG_0175.JPG

I bought a spanner off eBay & tied it to the engine in case I needed to change the impeller in an emergency.
 
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I think 6mm is right, they are tiny and very easy to drop in the bilge. If I remember, they are on the reverse side, so easier to remove the complete pump and work on it in comfort.

You are thinking of the 2GM which has a very different water pump arrangement. 1GM bolts through the front timing cover and a pig to remove.
 
My 1GM10, 2015 vintage, requires a 7mm spanner for the impeller cover, which is located behind the crankshaft pulley.
I had to buy the spanner specially.
 
You are thinking of the 2GM which has a very different water pump arrangement. 1GM bolts through the front timing cover and a pig to remove.

You are right, of course. My memory is going! I've had both engines, that's my excuse.
I reckon the 2GM water pump is the more difficult to work on, it seemed to be an afterthought in the design.
 
The Yanmar toolkit that came with my 1GM10 had about three open ended spanners and a reversible screwdriver. I can't remember off hand what the sizes are, but they've lasted 20 years and coped with all but one job, though ring spanners are preferred to stop the nuts rounding. A standard range of metric sizes should suffice.
 
My 1GM10, 2015 vintage, requires a 7mm spanner for the impeller cover, which is located behind the crankshaft pulley.
I had to buy the spanner specially.

+1 but I now have a speedseal. Note that the threaded parts of the thumb screws are every bit as fragile as the original bolts so keep a spare. Also, some Yanmar bolt heads are NOT metric standard e.g. 9mm af on 6mm threads.
 
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