Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 14-10-2016, 18:02   #1
Registered User

Join Date: Apr 2014
Location: FLEMING iSLAND, FL
Boat: Morgan 323
Posts: 8
Yanmar 3GM

I have a 3GM aboard my Morgan 323. I have the hand crank to start it manually. I move the two decompression levers back, but I still have a compression that I can't pull the crank through. I assume that the engine should free-wheel until I activate the decompression levers. Am I doing something wrong, or is this 70 something body showing it's age?
__________________

__________________
pacerow is offline   Reply With Quote
Old 14-10-2016, 18:11   #2
Registered User
 
four winds's Avatar

Join Date: Oct 2010
Location: Wandering the US Gulf Coast
Boat: 78 Pearson323 Four Winds
Posts: 1,943
Re: Yanmar 3GM

Does the 3gm have only two levers?

3gm30f has three.
__________________

__________________
Life begins at the waters edge.
four winds is offline   Reply With Quote
Old 14-10-2016, 18:15   #3
Registered User

Join Date: Feb 2010
Location: Melbourne
Boat: Compass 28
Posts: 274
Re: Yanmar 3GM

The 3gm has 3 cylinders, so you have one more lever to go.

Mind you, you'll be a special person if you can hand-start it. It might be possible if you have adequate room to use your muscles to swing the handle, but my 2GM is cramped. I'm sure I'd strong enough if I had the space, but so far I haven't managed a hand-start.

Cheers, Graeme
__________________
lockie is offline   Reply With Quote
Old 14-10-2016, 18:16   #4
Registered User

Join Date: Apr 2014
Location: FLEMING iSLAND, FL
Boat: Morgan 323
Posts: 8
Re: Yanmar 3GM

Only two levers and rated at 20 or 22 hp
__________________
pacerow is offline   Reply With Quote
Old 14-10-2016, 20:06   #5
Registered User

Join Date: Jun 2014
Location: Baltimore, MD / Albany, NY
Boat: Alberg 35
Posts: 120
Re: Yanmar 3GM

Is it possible you have a 2gm? I have a 3gm30 and it's got three cylinders, three injectors, rated for 27 hp.
__________________
Jim Eaton
s/v Pendragon Alberg 35 #175
Pendragon35 is offline   Reply With Quote
Old 14-10-2016, 20:12   #6
Registered User

Join Date: Apr 2014
Location: FLEMING iSLAND, FL
Boat: Morgan 323
Posts: 8
Re: Yanmar 3GM

Plate says 3GM, have three injectors but only two decompression levers.
__________________
pacerow is offline   Reply With Quote
Old 14-10-2016, 20:23   #7
Registered User
 
four winds's Avatar

Join Date: Oct 2010
Location: Wandering the US Gulf Coast
Boat: 78 Pearson323 Four Winds
Posts: 1,943
Re: Yanmar 3GM

Hey Jim, the 3gm is a completely different engine from the 3gm30f. The OP said it was 22hp (2gm 18?) and has been down in there with a hand crank getting some exercise. Seems like he should be aware how many levers it has.

But I find it curious it has two on a three cylinder.

Though if I get caught with a weak battery I open one of three on my engine and fire it up. The third cylinder comes online by itself after starting.

So maybe there is some rational for only two levers on this older design engine. And could explain why it appears to still have compression during hand starting.

May have to Google 3gm images.
__________________
Life begins at the waters edge.
four winds is offline   Reply With Quote
Old 14-10-2016, 20:29   #8
Registered User
 
four winds's Avatar

Join Date: Oct 2010
Location: Wandering the US Gulf Coast
Boat: 78 Pearson323 Four Winds
Posts: 1,943
Re: Yanmar 3GM

Quote:
Originally Posted by pacerow View Post
Plate says 3GM, have three injectors but only two decompression levers.
Well there you go. Not quite senile yet, huh pace. :- )

But you still have one cylinder in compression then. Never tried hand starting yet on mine. No crank lever on board, and the fitting is somewhat blocked on the freshwater version of my engine.
__________________
Life begins at the waters edge.
four winds is offline   Reply With Quote
Old 14-10-2016, 22:09   #9
Registered User

Join Date: Feb 2007
Location: Great Neck, N.Y.
Boat: Lancer 30, Little Jumps
Posts: 488
Re: Yanmar 3GM

I only know about my 3GM (and the half dozen i have seen/worked on in the last 30 years.)
...and I can assure you that my 3GM 22.5 h.p. raw water(made between 1983 and 1985)
has 3 decompression levers.
Jim's 3GM30 is a later version of the same engine with bored out cylinders producing 27 h.p.
Never even tried to hand crank as crank handle blocked from full resolution and
have never heard of anyone hand starting a 3GM, (maybe a 1GM or 2GM) but never a 3GM.
Sure if one needed a hand crank some 3GM owners would donate one, including me.
__________________
hugosalt
s/v Little Jumps
Lancer 30
hugosalt is offline   Reply With Quote
Old 14-10-2016, 22:58   #10
Registered User
 
four winds's Avatar

Join Date: Oct 2010
Location: Wandering the US Gulf Coast
Boat: 78 Pearson323 Four Winds
Posts: 1,943
Re: Yanmar 3GM

Yes, in fact it was the earlier 3QM that was a completely different design from the 3GM and later the bored out 3GM30F.

Point of correction, the 3GM was made from '80-'83, and the 3gm30f from '83 to 2005.

That most aft lever sorta hides back there by the breather assembly. Not nearly as out in the open as the others. Maybe the OP will spot it upon closer inspection.
__________________
Life begins at the waters edge.
four winds is offline   Reply With Quote
Old 15-10-2016, 03:07   #11
Registered User

Join Date: Apr 2007
Location: Australia
Boat: Modified Roberts 36' (stretched to 39')
Posts: 1,261
Images: 7
Re: Yanmar 3GM

I found even with a fairly flat battery I could usually get the starter to spin up the engine and drop one valve lifter to get it to start on one cylinder then drop the other two. Never even tried to hand crank it, far too ambitious for me.
__________________
RaymondR is offline   Reply With Quote
Old 15-10-2016, 06:09   #12
Registered User
 
Rhapsody-NS27's Avatar

Join Date: Oct 2010
Location: VA, boat: Deale, MD
Boat: 1981 Nor'sea 27
Posts: 1,348
Re: Yanmar 3GM

Quote:
Originally Posted by hugosalt View Post
...and have never heard of anyone hand starting a 3GM, (maybe a 1GM or 2GM) but never a 3GM.
I've only been able to manually start my 2GM after my rebuild AND after the engine was already warmed up. (haven't tried a cold start yet)

But, that is still a very hard workout to crank this engine even when it's warmed up. I know I've seen 1GMs start manually, but haven't heard of anyone trying it on a 3 cylinder engine.

Best of luck to anyone who tries.
__________________
Daniel - Rhapsody Blog,
ďA sailorís joys are as simple as a childís.Ē ó Bernard Moitessier
"I don't need therapy, I just need my boat"
Rhapsody-NS27 is offline   Reply With Quote
Old 15-10-2016, 07:06   #13
Registered User

Join Date: May 2014
Posts: 421
Re: Yanmar 3GM

The 3gm isn't really meant to be hand cranked. There is a reason they bolted a cover over the hand crank boss.
__________________
pcmm is offline   Reply With Quote
Old 15-10-2016, 08:18   #14
Registered User

Join Date: Feb 2007
Location: Great Neck, N.Y.
Boat: Lancer 30, Little Jumps
Posts: 488
Re: Yanmar 3GM

[QUOTE=four winds;2235513]Yes, in fact it was the earlier 3QM that was a completely different design from the 3GM and later the bored out 3GM30F.

Point of correction, the 3GM was made from '80-'83, and the 3gm30f from '83 to 2005.

Thanks for correction. Have to start checking my recall/memory.

Somewhere on line is history/time line of Yanmar marine motors
is either on Mack boring or Torrenson web site...(recalled from my questionable memory!)
__________________
hugosalt
s/v Little Jumps
Lancer 30
hugosalt is offline   Reply With Quote
Old 15-10-2016, 08:37   #15
Registered User
 
four winds's Avatar

Join Date: Oct 2010
Location: Wandering the US Gulf Coast
Boat: 78 Pearson323 Four Winds
Posts: 1,943
Re: Yanmar 3GM

I use the pdf from Mack Boring attached.
Attached Files
File Type: pdf tmp_12427-Yanmar-model-ID-1848779918.pdf (18.4 KB, 24 views)
__________________

__________________
Life begins at the waters edge.
four winds is offline   Reply With Quote
Reply

Tags
3gm, morgan, yanmar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for Yanmar 3GM manual Fotoman Engines and Propulsion Systems 5 28-09-2015 02:48
Yanmar 3GM(D) Shakes and Loud - Transmission? geoffr Engines and Propulsion Systems 42 30-09-2009 23:07
RPM's Yanmar 3GM engine bobelon Engines and Propulsion Systems 10 31-03-2009 11:42
2 Yanmar 3GM For Sale S/V Mother Ocean Classifieds Archive 7 29-09-2008 14:22


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:00.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.