Tom Plummer
Member III
:0305_alar For several years I have been vexed by a problem with my Yanmar. When forced to motor the thing will start and purr like a kitten. It will run at cruising speed for about 2.5 hrs. then suddenly it drops to an idle. After about 5 to 10 seconds it revs back up to cruising speed and runs for between 20 & 30 minutes. Then it drops back to an idle for 5 to 10 seconds and repeats the whole process over and over again until I shut it off for the night. The next morning it repeats the process all over again.
Over the years I changed all of the filters so many times I think I own a good portion of Racor and Yanmar. I learned and applied Glyn’s gently rocking the Yanmar filter technique and had the tank polished to no avail.
At the Seattle Boat Show the Yanmar dealer said that it sounded to him like I had a hairline crack in the lift pump, so I replaced it, no joy. He had also suggested that I put an inline pump at the tank to help the lift pump and replace my fuel lines. In the process of doing that today I found something I did not expect. Screwed into the output side of the discharge elbow at the top of the tank was a check valve. It was so crudded up that I thought is was a oddly shaped reducer. It wasn’t until I used a dental tool to clean out the inlet side of the check valve that I discovered the ball.
Does anyone else have a check valve on their fuel tank? The boat is a 1981 E35-2 engine location is under the companion way ladder and it appears to have the fuel tank.
Over the years I changed all of the filters so many times I think I own a good portion of Racor and Yanmar. I learned and applied Glyn’s gently rocking the Yanmar filter technique and had the tank polished to no avail.
At the Seattle Boat Show the Yanmar dealer said that it sounded to him like I had a hairline crack in the lift pump, so I replaced it, no joy. He had also suggested that I put an inline pump at the tank to help the lift pump and replace my fuel lines. In the process of doing that today I found something I did not expect. Screwed into the output side of the discharge elbow at the top of the tank was a check valve. It was so crudded up that I thought is was a oddly shaped reducer. It wasn’t until I used a dental tool to clean out the inlet side of the check valve that I discovered the ball.
Does anyone else have a check valve on their fuel tank? The boat is a 1981 E35-2 engine location is under the companion way ladder and it appears to have the fuel tank.