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Seeking 3GM30F/3YM30F, or a competent mechanic to rebuild mine - Seattle

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Located in Seattle and for a J/35 (if that matters).

Anyone know a reasonable diesel mechanic, or someone selling a drop-in read Yanmar 3GM30F?

Mine needs some TLC. It's noisy, stinky and hard to start. Hasn't gotten any worse in over 5 years, but I'd like it to be more cruise-ready. So gotta either pull and rebuild mine, or swap out with one someone had already reworked. Interested in an upgrade to the YM (glowplug version).

If you know someone selling a 3GM30F/3YM30F, or someone who knows these really well and wants to rehab mine, please put us in touch.
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Any decent diesel shop should be able to handle it. There's nothing magic or unique about Yanmars.

The farther they are from salt water the cheaper they are.

If it was me I'd find a diesel person who (for a fee) would babysit me while I did it myself.

I did that with a Hi Po Chevy small block and it was a great experience plus I got a blueprinted engine for the price of the parts plus a few bucks.

Lots of benefits - you know every inch of your engine, you know everything was done right, you save a bunch and when you light it for the firs time it's damn near as good as sex. :D

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10 hours ago, See Level said:

Auxiliary Engine Services at shilshole might be a good place to start

They did a great job with the 3gm on my boat. 

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24 minutes ago, Alex W said:

They did a great job with the 3gm on my boat. 

Ballpark what is it costing to have a mechanic rebuild a 3GM these days?  Mine is ok for now, and it will be babied going forward, but I'm curious what I might be in for down the road.

I have heard that rebuild cost is the same as replacement, but that might be a rumour spread by the people who sell them.  

I haven't rebuilt an engine before, but like the $10K rig overhaul I'm doing that will cost me $2K, I'm happy to spend time learning how to do it and farming out the stuff that is beyond my ability like resurfacing the head.  I have access to "that guy" as well.

A rebuild kit doesn't seem to be too expensive:


Nothing could be worse than R&R-ing my OMC Saildrive 5 or 6 times BITD.

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Sorry, I can’t help there. My engine didn’t require a rebuild.  I had a compression test done first because I was worried that it was time for a rebuild, but my engine was in spec. 

I had them do a lot of work (replacing hoses and pumps that were overdue), but the major solution to my problems was replacing the injectors. I had identified this as a problem earlier and tried replacing just the nozzles without adjusting them. That was a waste of time and money and the new nozzles were a mess in under a year. Aux Marine fully replaced the injectors and that solved all of my problems — low output, smoke, hard to start. 

It’s been 2.5 years since that service and the engine still runs very well. 

I found it well worth having an experienced Yanmar mechanic spend a day with my engine.  

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9 hours ago, Ishmael said:

Thanks, mine looks to be in much better condition than that one.  4K hours but starts and runs perfectly even in the cold, no corrosion, no leaks, 3 out of 4 mounts excellent and the other one is good.  I suppose I could get an oil analysis done on it, but I'm wondering whether that's worth doing at this point.  It lives another 2-3K hours, or it doesn't and I have to do something about it.

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