The fresh water cooled 20GM Yanmar on my Hunter 31 has run fine for years, but recently, adfter running for about one hour, it just slows down with throttle open. Eventually it stalls, but will usually start immediately afterwards. No obvious leaks in in fuel delievery lines. Did notice after last episode that outside of fuel filter on engine was wet with fuel. Does not appears to have anything to do with whether under load or not. Would appreciate any suggestions as to what to do. Thanks, Harry
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T
Tracy
...but it slows to a stall...
Hi Harry, When an engine adjusts its idle up AND down all by itself it is often a vacuum leak, but the fact that it runs fine for about an hour before just slowing and stalling confuses me. It almost sounds like the choke (automatic, I'm assuming) is stuck closed and as it warms up just chokes the engine (but an hour is a long time... )Does it happen every hour or just the first one? Another possibility is that the float in the carbeurator is sticking... Does it turn right over or does it take a few attempts?
Hi Harry, When an engine adjusts its idle up AND down all by itself it is often a vacuum leak, but the fact that it runs fine for about an hour before just slowing and stalling confuses me. It almost sounds like the choke (automatic, I'm assuming) is stuck closed and as it warms up just chokes the engine (but an hour is a long time... )Does it happen every hour or just the first one? Another possibility is that the float in the carbeurator is sticking... Does it turn right over or does it take a few attempts?
T
Ted W.
P
Pete
fuel leak
you symptoms sound like a fuel leak or bad filter change the filter and o ring! you are not so much leaking fuel as your are sucking air into the system.
you symptoms sound like a fuel leak or bad filter change the filter and o ring! you are not so much leaking fuel as your are sucking air into the system.
M
Mike McKendy
Screen crud
I've got a variation on the problem cited and I think it is likely crud on the screen of the pickup tube as Ted mentioned. I need to remove the tube from my 30"T" but don't know how it is attached to the plastic fuel tank. Anyone know how it's arranged, Mike McKendy "Sea Sharp"
I've got a variation on the problem cited and I think it is likely crud on the screen of the pickup tube as Ted mentioned. I need to remove the tube from my 30"T" but don't know how it is attached to the plastic fuel tank. Anyone know how it's arranged, Mike McKendy "Sea Sharp"
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stephen
T
Tony Gash
engine slows down
Recently had a similar problem with my Yanmar 3HM35F. Sounds like you have a leak near the fuel filter on the engine. Check the hose to the filter from the pump which an o shaped end with a bolt to the filter. This did come loose on mine and caused a problem. If outside of fuel filter is wet, it had to come from somewhere, maybe the bleeding screw on top of the filter? My recent problem proved to be a slight air leak where the elbow was connected to the fuel tank at the beginning of the fuel line. A quarter turn with a wrench did the trick. Hope this helps!
Recently had a similar problem with my Yanmar 3HM35F. Sounds like you have a leak near the fuel filter on the engine. Check the hose to the filter from the pump which an o shaped end with a bolt to the filter. This did come loose on mine and caused a problem. If outside of fuel filter is wet, it had to come from somewhere, maybe the bleeding screw on top of the filter? My recent problem proved to be a slight air leak where the elbow was connected to the fuel tank at the beginning of the fuel line. A quarter turn with a wrench did the trick. Hope this helps!
Engine filter or washers.
Harry: If you had fuel on the filter housing you should first check the filter. These can be easily overtightened. That can cause the metal to strip out or possibly even a crack can occur. Also be sure to check the washers for the bleed screws (nylon) and the high pressure lines. I believe that these have the banjo washers (crush type). These banjo washers shouldn't be reused, only replaced. I think what is happening is the fact that you have fuel in the system. Once you run it for a while you have consuming more fuel than you are able to pick up so the engine is starved for fuel and it dies. Once you restart your engine you resupply the system and start the procedure over again. I believe that these fuel filter housings are about $35 and the washers are somewhere around a buck each. The real problem if finding the cause not the cost of the parts.
Harry: If you had fuel on the filter housing you should first check the filter. These can be easily overtightened. That can cause the metal to strip out or possibly even a crack can occur. Also be sure to check the washers for the bleed screws (nylon) and the high pressure lines. I believe that these have the banjo washers (crush type). These banjo washers shouldn't be reused, only replaced. I think what is happening is the fact that you have fuel in the system. Once you run it for a while you have consuming more fuel than you are able to pick up so the engine is starved for fuel and it dies. Once you restart your engine you resupply the system and start the procedure over again. I believe that these fuel filter housings are about $35 and the washers are somewhere around a buck each. The real problem if finding the cause not the cost of the parts.
J
John McDaris
stalling motor
I have a friend that had the same problem, it was the washers on the fuel filter, leaking, and sucking air.
I have a friend that had the same problem, it was the washers on the fuel filter, leaking, and sucking air.
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