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Yanmar 3QM30 F

Has anyone tamed this beast? Had the motor mounts replaced by an experienced mechanic yesterday followed with a reasonably good alignment. I don't think the alignment is perfect but close. Had this done because the mounts are original and thinking that much of the vibration to the boat is due to the old rubber in the mounts. Unfortunately even with new mounts and another alignment, she's still a bronco in disguised even at idle. The mechanic suggested having the injectors rebuilt or cleaned. He's thinking is that doing this may smooth her out somewhat but that the Yanmar is what it is. My prior boat, Hunter 28.5, had a 2GM20 that was a very loud and jumpy but when I had the injectors rebuilt, it was like a I got a new engine! (it also helped in that boat to replace the 2 blade prop with a 3 blade prop). With the 3QM, am I looking for trouble doing an injector cleaning or rebuild? Has anyone tried this to tame this beastly machine with this. In it's defense, it is very reliable and gets me there and back every time. Any suggestions if the injectors are not the answer?
 
Hi John
Do not try this at home!
Confronted with the same problem 25 years ago I decided on the Aquadrive CVB 05.5
It stared at me for 3 years from the box while I tried to summon the courage to install it.
It is a CV joint that mounts the rear of the tranny. Here's what I did:
While at anchor no less.
Move the engine forward 3"
Cut the prop shaft with a carbide blade
Heavily modify the engine room door
Fabricate a stainless steel bulkhead to mount the Aquadrive; the thrust is not transferred to the engine mounts.
Fabricate a 3rd set of motor mounts to attach to the rear of the engine block
The engine and transmission are supported by 6 hydraulic Vetus MITSTUEN motor mounts with epoxy potted anchor bolts into the stringers
The Aquadrive tolerates almost 15 degrees of misalignment.
The Yanmar can do it's evil dance with most of it being absorbed by the mounts.
Bottom line is that I like it. Most noise I have is the cavitation of the 4 blade feathering prop. Twice the noise of a 2 blade. Should have used a 3 blade.
 
John
The Yanmar 3QM30F is known as a rock crusher. It is a slow RPM very heavy diesel. It weighs in at about 200lbs heavier than a more modern 30hp engine. It revs much slower then todays engines to reach the desired horsepower. That being said, it is a workhorse. Our 3QM30F with over 6000 hrs on it and runs fine. The motor mounts have been changed, twice. The injector pump has be rebuilt. The injectors have been replaced. The alignment has always been well maintained. The prop is a fixed 3 blade 16 x 11 RH. It's a noisy running machine, period! The best you can do is give it frequent oil changes, clean diesel, and fresh clean air. Compared to a newer machine it will be rough running cousin, but if well cared for it will always get you home.

Jim
 
We also have the original 3QM 30 on Vixen. She has been tried and true faithful over her 40+ years of use. John we don’t seem to have the problems you have, I don’t know why. At idle she runs very smoothly with no problems, between 13 and 1500 RPM she will shake your drinks for you. At about 1700 RPM to about 2100 she runs fine. I have not replaced the fuel pump nor the injectors nor had them rebuilt. I had to replace the motor mounts probably 15 years ago maybe more, because the forward Starboard one had failed. The cause was the manual fuel pump primer located above it had been dripping for years and I didn’t know it. This obviously was a very small drip. If I had to guess I would do the injectors first. If that doesn’t work then I’d look at the injector pump.
Possibly by cause of good luck, is because I have treated every drop of diesel that has gone on the boat over the last 40 years with a number of four separate fuel treatments. Maybe they works and maybe I’m lucky
good luck
 
Apples & rock crushers, but my Perkins ran & started noticeably better and smoother after I adjusted the valve clearances. An injector rebuild stopped most of the start up smoking. Then as Jim said: clean fuel, air and oil in the crankcase is all diesel wants.
Oh yeah, an impeller with blades on it too.
 
Thank you all for your input. I am intrigued by John's remedy to solve this issue. That took a leap in faith for sure. I will look into that. I do think I would haul out if i under under take that route. Just this week, a new trawler became my slip neighbor. the owner is a diesel mechanic and others know him to be very good in marine diesels, most large engines however. He was kind enough to hear and see the Yanmar do its dance and notice first thing my back stays whipping around with each spin of the engine. So he took a closer look below. He suggested what Jim, Dave and Dick suggested but in steps. First he suggested to have fuel treatment from Johnson diesel fuel additive, run it to temperature for a couple of hours under a load and see if that will help clean the injectors. If that doesn't help and smooth out the idle, then to have a rebuild. He explained that if one is not injecting fuel correctly, it really causes and imbalance, two not working probably, even more. Then without a doubt, a valve adjustment which I don't believe has ever been done. He also wants to ck again the shaft alignment as that is not difficult to do even with a dripless shaft log. So that can probably be dialed in better. After that, it may be as Jim, said, its nature and it is what it is. But he added that this era Yanmar was well built, maybe over built and designed to run 24/7 in agriculture applications so it is a heavy engine built to take punishment but it also punishes back in the process! One thing for sure, it is reliable and and gets me back in my slip. I have ordered valve cover gasket and once in, I will get the valve adjustment done. If a rebuild is necessary on the injectors, I will report back with the results of that. I'll try to get a video posted once all is done. Thank you kindly for you input folks, helpful and reassuring to me that the 3QM just has it own personality.
 
John
I adjust the valves every other year. It's not a difficult job. The only issue with doing the job is the valve cover gasket. The Yanmar gasket is a rubber piece that does not have a lip, either on the cover or the block, to keep it in place. If the valve cover nuts,(3), are tightened just a bit too tight the rubber gasket squeezes out and the cover leaks. I now use a stiff gasket material about the same 1/8" thickness as the Yanmar gasket. It has to be cut out, but the cover is a perfect template. A light coating of Form-a-gasket on it and it will never leak.

Bonnie and I just got home from looking at boats in the 34 to 36' range for my Son and his wife. I always thought it was a bear to work ok Dana's engine the way it was placed in the boat. After seeing some other boats today, I'm changing my opinion of the access to Dana's diesel to one of delight. Some of the boats we looked at had no easy way to service the machine. We got it good!

I don't know if this will be the same on all the Morgan Yanmars. To adjust the valves the engine needs to be hand cranked to get the aft most set of valves to top dead center. To do this I release the compression lever, then using a 1/2" drive ratchet with, I think, a 7/8" short socket to manually turn the engine until the lower fan belt pulley, PTO, is in a position with the embossed number in a square is in the 6 O'Clock position. Other engines may not have that embossed number or it may not be positioned as mine is. Once the aft cylinder is at TDC, both rocker arms will be free to wiggle, not under pressure, and can then be set to the .016 thousands that is required. Then hand crank to the next cylinder, then the next. Hope this helps.

Jim
 
Jim, I follow your instructions above and thank you. I will get them to Lee, the mechanic that will be doing the adjustment. The pully does have the number in a square. Now I know why it is there. Having trouble getting the authorized Yanmar parts supplier to return calls and email, still in a covid mode. So I may cut our the gasket and use the tube of gasket maker. I did that for the impeller gasket. Thanks also about how to get the engine to the desired spots for the valve adjustments. I am betting on this adjustment to make her happier in running. I do think and agree with you that we are lucky with engine access. Once I accidently locked myself in the port cockpit locker when it shut on me and self locked. Knowing that I had left the access panel open inside the boat, I crawled over the engine into the inside of the boat with only a ripped shirt but my calls went unheeded and I did not want one day for someone to find my skeleton in the boat! That's when I knew we had some room to move about in there. Thanks as always for great information Jim.
 
John
Your post really made me laugh out loud. One cold spring day in early April, late on a Sunday afternoon, I was alone working on the boat when it was up in the boatyard. The boatyard crew wasn't there that day and the other owners were long gone from their boats. I was working in the port cockpit locker doing a quick little project. In an instant, the wind blew the cockpit locker cover down and it self locked as yours did. There was no one to hear my calls and this was long before cell phones. The plywood divider was in place between the locker and the engine compartment and I didn't have tools to unbolt it so there was no escape across the engine as you did. I was too large to fit through the garbage door into the galley. My wife was going to be working that night and wasn't expecting me home before she left for work. It looked like I was there for a very cold night. I then figured that the latch easily flipped into the locked position, then it might just as easy be flipped into the open position. If I banged on the cockpit bulkhead just at the inside of the latch, I might be able to unlock it. It was on something like the 113th try that my pounding was coordinated with the pushing up of the cover and I was freed from my prison.

I learned a number of lessons from that experience. Always tie off the hatch cover when inside a locker. Always let someone know when I expect to be home from a days work on the boat. And now in this age of cell phones, always have the phone with me.

Your post made me laugh, not because I was laughing at your predicament, but because I realized that there was someone who had the same embarrassing experience as I did and is man enough to admit it. Just another small point that makes this Morgan brotherhood so enjoyable. Good luck with the valve adjustment.

Jim
 
Jim, I glad you could sympathize and empathize with me. You were smarter than me by undoing the latch by the coordinated bumps and pushes. My latch is not hard into the fitting with locked, it rattles a bit when the Yanmar is running which leads us back full circle to this thread, but I will keep that in mind your method as well should that happen to me again! Yes there is a kinship and I am glad I found this site! Take Care Jim!
 
John

Stories like ours might be embarrassing at first, but they make great sea stories when the rum is flowing.

Jim
 
John and Jim, believe it or not I did the same thing. I was out on the boat alone next to our house a number of years ago. The same thing that happened to Jim happened to me, or I grabbed the outboard edge of the locker and pulled the hatch down on top of me then it hooks on the holler. My wife was in the house but I had no way to communicate with her. I did the same thing Jim did, I banged on the latch on the cover and finally it released. I saved myself from smelling diesel all night.
 
Good stories, though I know it wasn't fun creating them. It's interesting, I have been clamouring and messing about in the same space many times. I always thought "I need to tie the hatch open around a winch or something", I guess I have been lucky! I will tie it open next time!
 
I hate to admit it as I am not sure why now I was in there to begin with, but I have actually fully gotten in the wet locker compartment. Thank goodness there is no locking mechanism for my lid, actually, I had to take the lid off to get in. I wish I can remember why I had to get in there. The refit has taken me down and into many paths too many to list.

By the way, had the valves adjusted Tuesday. The valves was out of specs, but not by much. However, bringing it to the adjustments that Jim gave in this thread proved to help the bronco settle down quite a bit. I assisted the mechanic by handing tools to him, we keep telling the Yanmar, "we come in peace, we are your friends". So out of gear, she runs much happier. Amazing how a little adjustment improved its idle. Now the shaft re-alignment is forthcoming.

Lastly on an entirely different topic (sorry), today we went out to sail Quest in 20 to 25 knots of wind, small craft warning but had to go. Needed the experience. Doubled reefed the main but when we cleared the harbor, we first used 3/4 of the head sail out and no main. This notwithstanding, jib alone we had speed constant 7+ and down waves, hitting 8 very briefly from time to time. Really did not need the main at all. My boat is light with 1/2 tank of fuel and hardly any water in the tank. My friend could not believe her speed considering having to cut through the waves. I did have trouble tacking with the 3+ ft waves being so bunchy due to the shallow waters of the Mississippi sound and not having the main up. So we allowed the boat to go down wind under jib and jibed for a change in heading. Good sail. She handles well notwithstanding my lack of sailing skills.
 
Dick
Thanks for your tale of a port hatch adventure. I'm wondering how many more Morganeers have had the same experience? Now I really don't feel so bad.
John
Glad to hear the valve adjustment worked. And that you had a good sail. I do the valves every other year. I used to be able to get into the lazzerette locker in my more nimble days. Now I will ask my 8 year old Grandson to help if it needs to be done again.

Jim
 
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