My engine is a 350 Volvo. Thought I had a bad fuel vent as I was losing top
end power after running for 5 minutes. Changed vents and went out again.
Same symptoms, run on step at 3500 rpm for 5 minutes then the rpm's drop
down to 2500 and it seems to run fine. I stopped and checked the
anti-siphon valve and fuel filter. After siting for 5 minutes cranked it up
to 3500 and it ran for maybe 30 seconds then dropped right down to 2500 or
so. No chugging, just slowly drops the rpm's like your backing down the
throttle. We stopped and trolled for a few hours - 2 king salmon and two
coho - then went to head back. This time it took several minutes to start
the main. After starting it would max out at the 2500 or so range. while
back in the harbor at idle it was running very rough and died just before we
docked and would not start agin.. I'm wondering if I have a bad coil? I
was going to start there and change the ingitor and resistor as well. These
were replaced 3 years ago. Where else should I look? New Carb and Fuel
pump last year - only have 40 hours on each. New plugs and plug wires as
well? Thanks in advance.

linus