Need help - blocked Fuel lines 1991, Hunter 30

[John North]

While cruising at 2500 - 3000 rpm in choppy water - the Yanmar engine hestitated, lost power and eventually staled. I switched off and after a half hour was able to restart. I ran at 1000 rpm and was able to limp back to the dock.I suspected a blocked fuel filter and did indeed find sludge in the bottom of the filter which is located under the berth in the stern. I replaced the filter and cleaned the housing which of course caused emptied the line. I changed the smaller filter too even though it was relatively clean.How do I prime the filters? Is there a filter on the pickup in the fule tank?I have worked at it all day and am defeated. Any suggestions?

 

[Guest]

What you need to do John...

is check the pickup tube in the fuel tank. Most likely you will find a tiny screen on the end that was intended to keep gunk out of the fuel lines. However, this just tends to clog eventually starving the engine. My advice is to remove it and let your filters trap the gunk. This is the way I've been running for 10 years now WITHOUT ANY PROBLEMS of this type. As for priming the filters, that depends on what kind you have. I have a racor that has a 'priming pump'. Open the vent line, pump to prime, then attack the Yanmar filter. It would help to fill the filter canister as much as possible to eliminate the pumping process as much as possible. The Yanmar can be primed by opening the vent (10mm machine bolt) on the body top and then pumping the 'lift lever' located on the fuel pump itself. Do this until there are no more 'bubbles' coming from the vent you just opened. That's about it.

 

[gerald mcCombs]

fuel line problems hunter 30

You might also check the vent capscrew on the racor filter located under the aft berth. Some filter came with a nylon capscrew which tends to leak as it ages, racor later fixed this problem and repaced with one made of metal and a retrofit vent screw is available. If the vent is nylon replace it and don't look back because the air leak is so impossible to detect because it is so minor but it will cause the exact problem you experienced!!!