Yanmar 1 Cyl Runs For 30 mins

[Peter Baumgartner]

The engine on my new 1977 Cape Dory 27 (Hull 35), a 1 cylinder Yanmar, will only run for 30 mins and then quits. If I rebleed it, I can run for another 30. I have done this ~12 times over the last 3 days and am confident this is repeatable. It seems air is getting into the system somewhere....

But how do I find out where? I have tightened and adjusted all I can think of.



pbaumgartner@mindspring.com

[Lyn Heiges]

The engine on my new 1977 Cape Dory 27 (Hull 35), a 1 cylinder Yanmar, will only run for 30 mins and then quits. If I rebleed it, I can run for another 30. I have done this ~12 times over the last 3 days and am confident this is repeatable. It seems air is getting into the system somewhere....

But how do I find out where? I have tightened and adjusted all I can think of.

Peter,

I FEEL FOR YOU!!!

I have a Yanmar YSM-8 in my 1980 CD27 and she is the best engine I have ever seen -- BAR NONE!! I just went and visited her last weekend and she started by had the first "crank", as I was showing her off to a prospective purchaser, after having sat since November when she was winterized!

Now, I have had my fun after changing the filter and injector periodically over the 14-years I have had her! It only takes "ONE"!! bubble of air to stop the "D" thing and sometimes it holds in the fuel line until "shaken-free", I believe. I did replace the factory FRAM filter with a Racor 500FG many years ago and this helped the problem. I also installed a fuel shut-off between the fuel tank and the Racor to make life easier and this has seemed to help.

I am surprised that it is taking as long as it seems to be to give you trouble. Make sure the ONLY thing coming from the various "bleed" screws is fuel oil and ALL AIR BUBBLES STOP. You may find you have to waste more fuel oil than you think to reach this stage. I would make sure that the fuel hoses are all well seated and tight as well as they feed the injection pump, etc. Like a flat tire, you might but some fuel oil around each one and visually inspect any "changes" while it runs. There is also the possibility if the hoses are the originals, that they have deteriorated over the years. Yanmar does still supply all the parts and if you contact a Yanmar dealer, they can get them from the warehouse near Chicago. Yanmar is pretty reasonable in price too.

Good Luck!

Lyn Heiges
CD28 MOON CHILD (Yanmar 2GM20F)
CD27 GUILLEMOT (Yanmar YSM-8)



lheiges@compuserve.com

[Peter Baumgartner]

Thanks for the encouragement. I did finally get it.

I had installed a new fuel tank and a new Racor filter - so I guess there was lots of bleeding to be done. I finally stopped at West Marine and read a book they had on the shelf about bleeding one's diesel. It gave me a few more ideas. I replaced the one remaining old section of fuel hose and then went through the whole process again. The engine still stopped after (now) 15 mins. So I bled it one more time, but then after running for 10 minutes I opened the bleed valve on the top of the secondary filter, with the engine running. Some air came out! I repeated this again in another 10 minutes with the engine running. It never stopped again.

Now just for luck we now refer to our engine as "Old Dependable"!

Pete



pbaumgartner@mindspring.com