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Hi, I'm from NB Canada, any of you sailors on this forum would know where to buy a complete/overall rebuilt kit for a Yanmar 2GM20 engine?

Jan 4, 2006
3,914
Hunter 310 West Vancouver, B.C.
First of all, It would have to be a Yanmar dealer as Yanmar is obsessive about territory.

Secondly, never heard of an overall/rebuild kit (doesn't mean it doesn't exist). I would think you're looking at what needs replacing and then order part by part.

What needs replacing ?
 
Jan 30, 2012
1,093
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
I have built several of the GM series. In fact - have a fully machined (factory specs) 2GM20 in the shop now ready for assembly.

So to the point - Johnstone is right. While the idea of a rebuild kit is a good one (US motor companies do offer engine kits) Yanmar offers nothing of the kind. You need to decide these things for yourself.

For example - the gasket kit for the 2GM20 is also for the heat exchanger version too - so there are surplus items in that kit. If you need to bore the cylinders there is only one oversized piston - but you need rings oversized too. If you sleeve the bores (a repair that that works fine on the sea water cooled version because the operating temperatures are lower) you will need to make sure the standard pistons fit but you still need a new set of rings. Same if you just hone the bores. You may need oversized crankshaft bearings - maybe rods and mains both. Certainly the cam bearing and maybe (rarely) the cam/crank gear set too - but you need to measure.

Separately I would not do a rebuild without a brand new oil pump. Also I would not rebuild without a cam/lifter regrind unless the lifter wear was very spiffy (acceptable lifter wear is rare in the GM series by the way.) You need valve stem seals for sure - maybe also valve guides once you measure things. Maybe seats too. You will need to get the injector seals stack separately.

This is a sampling of the things you need to consider - there are a number of other things you need to consider, The point is - no matter what - there is no "kit" that could possibly include all the things you might need.

Keep in mind I do it the way I do it. Chances are your local automotive machine shop will be a valuable resource - after all you will probably need to go there anyway if you are serious about making sure that all things fit up.

Give me a PM if you have questions. Happy to discuss the matter over the phone.

Charles
 
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Oct 5, 2021
5
Bayfield 29 Caraquet
First of all, It would have to be a Yanmar dealer as Yanmar is obsessive about territory.

Secondly, never heard of an overall/rebuild kit (doesn't mean it doesn't exist). I would think you're looking at what needs replacing and then order part by part.

What needs replacing ?
Thanks Ralph, much appreciated. I will strip the engine and see what's needed as parts.
 
Oct 5, 2021
5
Bayfield 29 Caraquet
I have built several of the GM series. In fact - have a fully machined (factory specs) 2GM20 in the shop now ready for assembly.

So to the point - Johnstone is right. While the idea of a rebuild kit is a good one (US motor companies do offer engine kits) Yanmar offers nothing of the kind. You need to decide these things for yourself.

For example - the gasket kit for the 2GM20 is also for the heat exchanger version too - so there are surplus items in that kit. If you need to bore the cylinders there is only one oversized piston - but you need rings oversized too. If you sleeve the bores (a repair that that works fine on the sea water cooled version because the operating temperatures are lower) you will need to make sure the standard pistons fit but you still need a new set of rings. Same if you just hone the bores. You may need oversized crankshaft bearings - maybe rods and mains both. Certainly the cam bearing and maybe (rarely) the cam/crank gear set too - but you need to measure.

Separately I would not do a rebuild without a brand new oil pump. Also I would not rebuild without a cam/lifter regrind unless the lifter wear was very spiffy (acceptable lifter wear is rare in the GM series by the way.) You need valve stem seals for sure - maybe also valve guides once you measure things. Maybe seats too. You will need to get the injector seals stack separately.

This is a sampling of the things you need to consider - there are a number of other things you need to consider, The point is - no matter what - there is no "kit" that could possibly include all the things you might need.

Keep in mind I do it the way I do it. Chances are your local automotive machine shop will be a valuable resource - after all you will probably need to go there anyway if you are serious about making sure that all things fit up.

Give me a PM if you have questions. Happy to discuss the matter over the phone.

Charles
Thanks Charles. I'm the kind of person that like things to be done once and done right. Your info is very professional and will be very helpful. I will definitely follow your counseling on this one as I do not want this to be wrongly done. Regards, George
 
Jun 8, 2004
915
C&C Frigate 36 St. Margarets Bay, Nova Scotia
The Yanmar dealer locator shows five dealers under "Marine Recreational" in NB. I have found this parts list quite useful (found here on SBO under Owner Resources/General Downloads):
Yanmar Parts List
Note that some part #s and all prices are out of date.
 
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  • Helpful
Likes: ggrizzard
Feb 21, 2013
3,796
Hunter 46 Point Richmond, CA
This UK site Yanmar 2GM20 Engine overhaul kit (parts4engines.com) sells a Yanmar 2GM20 engine overhaul kit that includes:
  • Pistons x2 standard or +0.25mm sizes available, 75mm bore
  • Piston gudgeon Pin x2
  • Piston pin cir-clips x4
  • Piston ring sets x2
  • Set of Main bearings standard or -0.25mm
  • Set of Connecting rod bearings standard or -0.25mm
  • Set of gaskets and seals
Is this what you are looking for? If not, attached is a Yanmar 2GM20 parts list. Buy a service manual here Yanmar 2GM20 Marine Diesel Engine Service Manual PDF Download (marineservicemanuals.com)
 

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  • Helpful
Likes: ggrizzard
Jan 30, 2012
1,093
Nor'Sea 27 "Kiwanda" Portland/ Anacortes
The service manual gives you and your machinist the information necessary to do this job. The way Yanmar wrote this - the assembly chapter is the general guide and the separate chapters give the details (wear limits, dimensions and etc.) for each of the assemblies.

Cannot upload the manual here nor by PM - it is too large. PM me your email and I will send it to you if you don't already have the manual.

Charles
 
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