Yanmar 3GM30F

[Capt Pozzi]

I am having an issue with my 1992 Yanmar 3GM30F.
She has always been challenging to start. I have changed out the injector and it seemed to help for a very short time. Almost every-time I start her a cloud of black smoke envelopes me. I currently live in VA and I have recently changed the oil and filter, all hoses and air filter. I was trying to start her the other day and the starter head cranked. I replaced the starter and she turned over however wouldn't start. A friend recommended that I try ether and I tried to crack her and the new starter cracked. I have now been through two starters and she still hasn't cranked. Any recommendations?

Thanks in advance-

[a64pilot]

All that cranking may have hydro locked it? If so you need to get the water out ASAP.
If you can turn the crankshaft over a few revolutions by hand, it's not hydrolocked.
Hard to start issues are sometimes loss of prime, in other words air in the fuel.
Once you ensure it's not hydrolocked, I'd start with a compression check as low compression especially in cold wx will make one hard to start.
Does this engine have glow plugs? Inop glow plugs will definitely make one hard to start, but I don't think you have glow plugs.
If you do, never, ever use ether on an engine that has glow plugs, unless you ensure you don't use the glow plugs.


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[DeborahLee]

Open the compression releases that will allow you to release any hydro lock. As for the starter did you buy a Yanmar starter from a Yanmar dealer or a knock off. I went through 2 starters both Chinese knock offs they cracked the end bell. I found a great after market starter from these people Starter for YANMAR 1GM, 1GM10, 20GM, 2GM, 2GM20, 2GMF, 30GM, 3GM
I have had it in service for 4 years with no problem.

[sailorchic34]

GM series engines don't have glow plugs, but ether should not be used. I would make sure all low pressure fuel side banjo bolts are tight and bleed the system. Close the raw water valve while bleeding. Be sure to bleed the injectors. It can take some time getting all the air out of the fuel system.

If it still does not start, have a compression text done.

[DeborahLee]

Difference between knock off and after market is:
Knock off is a cheap imitation of an item looks identical with cheap parts.
After market is a different design sometimes good sometimes bad have found most after market to be better design.

[GordMay]

Greetings and welcome aboard the CF, Capt Pozzi.

[gonesail]

my 3GM was difficult to start in the cold weather (and we know it is freezing in VA) and needed almost full throttle when cranking. you will get diesel smoke at first and you must reduce throttle immediately to idle after it turns over. also you can increase the cetane rating of your fuel by using an automotive additive which may help. good luck and stay warm.