Deisel "Burping"

[Charlie]

I have taken the suggestlion and changed out the mixing elbow on my Yanmar 3GMF (1985 Hunter 34). It was about 50 % clogged. The engine will now come up to RPM. Now the bad news. The engine still starts to rap and belch black smoke about every 30 to 45 minutes when I run above 2500 rpm. If I catch it in time and decrease the throttle for 30 seconds I can rev the engine back up to 3,000 rpm for another half hour. If I do not catch it in time the engine stops and it takes about an hour before I can start it. Any suggestions will be appreciated.Thanks,Charlie

 

[DJ Dreyer]

Fuel, Air, Oil

Diesels are very simple which is one of reasons they are great in marine applications. They do need clean fuel, oil, and lots of air. I would take a look at all the filters on your fuel system first. Just change them if you have not this year. One bad tank of fuel can clog a filter in less than an hour (from experience!) Then check the fuel itself. Do you have a fuel-water separator? If not, put one on NOW! You can drain some fuel off from the bottom of a fuel-water separator into a clear, clean glass container and look at it for signs of water and dirt. There are additives that can help rid tanks of a small amount of contamination. Your tank may just be full of gunk and after awhile it starts to clog up the intake hose. The end of the intake hose MAY have a fine wire mesh which keeps the junk in the tank and out of the filter where you could get rid of the junk (not one of the better ideas in life). I would also check the fuel tank vent. If that is clogged it may cause your symptoms also. This is just a start and I am sure other people will give you some other ideas.Good luck and good hunting!

 

[Rick D]

Charlie, see reply..

..'Answer for Alex'. May be worth thinking about here, too. RD