Yanmar 1GM Starting Problem

[Ron Vanderveer]

GangI couldn't get our Yanmar 1GM started last week and wanted some input from the "co-conspirators" on these forums! The details: Hunter 27, Yanmar 1GM, two batteries switched. I tried the starter, and it turned over, but sounded weak and after about 10 seconds of cranking it started bogging. I stopped cranking at that point. I tried all of the battery switch positions to no avail. I had already suspected that the batteries would be low, due to lack of use by us lately and the fact that our 110 charger is not hooked up (long story). So I wasn't surprised that the batteries were weak.But what did surprise me is that when I tried to hand crank the engine to start it I was able to crank it over fine, but when I let go of the decompression lever I got almost no reaction from the engine. I had the key turned on. After releasing the lever, the cranking got a bit harder, but not much, and there wasn't any firing or sputtering from the engine at all. I did check fuel and it was air-free and spurting out at the appropriate points. I also remembered the advice about the cooling water intake, and shut that off during my attempts.I suspected that the batteries were too low to start the engine. So I have charged those and will re-install them today and try it again. But why did the starter turn over and not start the engine? Does a diesel require a higher "starting speed" to get going? And why the complete lack of reaction with the hand crank? Why do they even give me a crank if I can't use it!! I will let everyone know tonight if she starts for me with the newly charged batteries, but for future reference I wanted to know if something else was going on. Any thoughts will be appreciated.Take care,Ron Vanderveer

 

[David Foster]

Temperature?

Diesels start by igniting the air-fuel mix with compression alone. (Other models may have glow plugs to help, but not this one.) When we start ours on Saturday, I expect a long slog to get the cylinder head hot enough (through successive compressions to fire. That's the case whenever it is cold.I don't know about cranking - you are one of the first I have heard report trying. Our older Yanmar 1SB didn't come with a crank (from multople PO's.)Good luck with the recharged batteries!DavidLady Lillie

 

[john p]

I think I have the same boat...

I a 27' with the sb8 yanmar (third world putt putt). I have started it with the crank when my batts were low. No problem...Here is what I do:-set fuel throttle to about 3/4 position- release the decompress. lever-crank as fast as yoy can and on about the 5th turn release the decompress. lever. Mine will take off putting away every time.the trick is give it fuel and build up momentum with the crank before releasing the lever.

 

[Ron Vanderveer]

Charged batteries didn't help *grr

David, JohnThe batteries were not the culprit, as I had suspected. The starter is turning over fine, just no response from the old girl.David - its still in the 80's here, so temperature probably is not the culprit. Although that is good to know for our one month of winter in Florida! John - I expected it to behave as you described. I did have it cranking pretty good, release the lever, cranked once more, stood back, and nothing....One of my more-knowledgeable buddies suspects some water somewhere, although I didn't understand where he thought it was (fuel? crankcase? my brain?). So we'll have wait until Sunday to get some help from him.I'll try to remember to update this forum if I find out what the problem is.Thanks,Ron

 

[Steve Dion]

Battery condition.

Ron:Just because you have charged your batteries does not mean that they are any good. You need to either get a battery that is in good condition and try starting the engine or having your batteries load tested.They can show good voltage and not have the AMP to crank the engine.

 

[David Foster]

Diesel Mechanic?

At this point, I would sure be thinking about having one stop by to maintenance the engine, and troubleshoot the problem.But you can troubleshoot the engine and fix it yourself. My next stop on that path would be to buy a good diesel engine maintenance reference book from the chandelry. If nothing else, that would help me to work with and understand my helpful friend.Good Luck!DavidLady Lillie

 

[Ron Vanderveer]

The Solution (Maybe!)

GangHad my boater buddy, who is quite a MacGyver when it comes to boats, come over and we troubleshot the engine. Turns out that it was not the batteries (at least I got that part right!). Let's think of the number one problem with diesels? Fuel delivery!!As mentioned before, the tank was delivering fuel to the Racor, and the Racor was delivering fuel to the fuel pump. But I apparently did not do a thorough enough job bleeding the fuel lines (it may be that I just haven't done it enough). What we found is that there was a ton of air in the fuel lines, especially at the bleed screw at the top of the fuel filter housing. We thought at first that it might be a bad fuel pump.So Charlie rigged up the electric fuel pump (has been described and recommended on this forum many times) and got the lines cleared of air. Then we got her started using the electric fuel pump as the delivery mechanism. But we noticed that there was a bit of a leak from the bleed screw at the top of the fuel filter housing. So we started to think that the fuel pump might be okay, and that the bleed screw was cracked or stripped or something (there was some evidence to support this). So we hooked the mechanical fuel pump back up, bled the lines again, and she started and ran fine using the old pump. So our conclusion is that the fuel pump is probably fine, that in fact the bleed screw is damaged and was the reason that the air got in to the lines. We figure it was a slow leak, hence the problem only showed up when we hadn't started the engine in three weeks. I will probably end up tapping a new bleed screw into the fuel filter housing, but in the mean time we just glopped a wad of RTV onto the top of that bleed screw to try and seal it up. Seems to be fine.Bottom line: I thought I had bled the air out of the lines, but I hadn't, or I hadn't done it at all of the correct points. And diesels almost always have some type of a fuel problem if they won't start!Take care,Ron