Some bits of Odd Information - 1GM10

I was thinking of removing my engine next year - sort of getting my head around it. It could do with the engine mounts looking at - and the underside is not getting any better - ecpecially the lower parts of the alloy timing case. Its not hanging - but would be nice to give it an overhaul.

I have been on the phone to various suppliers - and online where I could find things.

An interesting place I found recently.

Ribparts - have a site where when you have registered, no fee, you can access the EPC ? - the electronic parts catalogue that all the dealers use for Yanmar. This lists everything, and especially useful ( if you download Isoview and use IE only ) - you also have the exploded parts diagrams for reference. You can access it with other browsers - but do not have the images of parts - and cannot order online. So it IE only I'm afraid - but very useful for sorting out part nos.

Generally - I have found the best and most savvy people to deal with are FrenchMarine - they really know what they are about - and know boat engines.

The main online sales outlets are Keyparts, Marine Power and Frenchmarine - also Rib Marine. I also use Rollo in Avonmouth ( no online presence ) - who can get any listed part within the week. I can go collect it on the way to the boat. Slightly dearer but a lot easier.

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So - what are the main stumbling blocks here. Apart from the main hassle of splitting the engine form her mounts - ie actually lifting it out - my main concern was availability of rebuild parts.

I had heard that there were no oversized piston available - yet my Yanmar manual says 0.25 ? When I asked the question of Rollo - a major Yanmar agent - they said none were listed.

They were right in some ways - none are listed on the main elecronic catalogue ! Yet - and Frenchmarine sorted this out - there is a supplemental listing - 'on paper', that cited the oversized availability. Took me ages to sort this - emails to Keyparts, he phoned Rib Marine ( they actually have one on their site for sale - £ 150, piston and rings )

So it just goes to show - even places like Rollo get it wrong !


I really think - now I have seen the bore, it may just need new rings and a re-hone. Its hardly worth putting in new rings though - as rings only, are almost the cost of a piston and ring set - albeit, oversized are more. The difference, inc the rebore at about £40 - is maybe £100 ?

I also have to count in a new gasket set at £75.

Engine mounts - if one goes with Yanmar are costly. Mine may be saveable - I don't know. Aftermarket can be had from £30 - £65 depending on type.

With the head off, starter, alternator etc - its not too bad a lump to move. The rear mounts may unbolt at the engine casing bracket - they are accessable. he front are not - but my fronts look shiftable on the main nuts.

This summer I shall have a try at them - see whats going to give !


On the special tools front - its a pretty picture. Just two really - and nothing special. The main crankshaft nut needs a 36mm long reach - and a 36/42 box spanner is available at about £16 - which meets the specs on clearance OD. That and a basic puller for the belt pully.

I very much doubt I'll need to be unpressing crankshaft mains etc - just maybe oil seals. The crankshaft has one end bearing set in a removable housing - so the crank pulls through ( flywheel end ) the other end is a solid pressed bearing. No intermediate.

The camshaft is a roller bearing sliding fit - nothing to pull.

The flywheel is just bolted on - five bolts, flat face fit with locator pin.

The main problem to me is the front timing case. Alloy - salt, long thin bolts through the casing ! Most of them I can try to shift in situ - and with it out one has a better fighting chance. They tend to sieze internally through the alloy case - corrode and shear. The casing itself is ok - some corrosion and water pitting low down under the water pump area. ( this engine ran for many years I think with badly leaking water pump )

I would be doing the engine at home - so would look at taking her out next winter. I scraped her off in Ilfracombe, zinc is ok. main and prop. So may antifoul her there in spring - or put her on the yard slip for a tide.

A simple A frame would lift it up to cockpit. Split the box off - then its managable by hand.

Its good to go through it in your head - something at times I shuddered at the thought of having to ever do it - but somehow when you decide you want to do it, its suddenly all sweet.

Its like this head - you see it as a major task yet I had it off in under an hour or so and its ben a doddle to take apart.

When I have a chance I will investigate the mounts - and the reachable timing case bolts.

Geoff - Uphill Pontoons, Dec 2013.