MerCruiser 350 problem
"Zrider" wrote in message
...
I am in need of opinions here before I spend any more $$$ on my
motor...
I have a 1999 Rinker with a carburated 250 HP MerCruiser 350. The
engine ran fine all last year, up to and including the day I had it
winterized. When I got it out this spring, it wouldn't start. It
wouldn't fire at all. I took it to a local mechanic, who replaced the
fuel pump, fuel filter, coil, and plugs. In a tank and in neutral, it
started and ran just fine.
Well, over the holiday weekend, I took it to the lake and dropped it
in the water. It started fine, and idled through the no wake zone
fine. However, it barely got on plane with just myself in it, and
maxed out at about 4000 rpm.
I had about 1/4 tank of old gas from last fall in the tank, so I
filled it the rest of the way with new fuel, and added a bottle of
octane boost. That didn't help - the engine actually started getting
worse. I thought maybe I had already clogged the new fuel filter, or
maybe had water in it (the boat was outside all winter) so I pulled
the filter and dumped out the gas, but it was clean and no water.
Finally, I tried carb cleaner, which was no help either. Now the
engine barely starts, and when it finally does, it maxes out at about
3800 rpm in neutral before cutting out real bad,
Sounds like bad gas/carb jets obstructed. Sure sign is that at some speeds
engine runs fine and as you advance throttle you have regions that missfire
(run rough). remove carb disassemble and dump in bucket with carb cleaner.
There are many chemicals claiming to be carb cleaner. NAPA makes one that
is very good. The carb should soak for more than 4 hours. Then flush the
jets with a can of spray carb cleaner.
That will fix your problems until next year if you don't add stabilizer
and/or run your carb empty before storage. I use the new 2 cycle oil with
stabilizer and mix 100:1 in the gas tank. Then run engine for 20 min with
flush ears attached to engine, last thing I do is to turn off fuel and let
run dry.
and will not even get to 2000 rpm under load. If your engine were running
smooth in neutral but under load exibited the symptoms you describe when hot
I'd suspect plugs/wire/coil. And possibly bad gas. Bad gas for me means
hard start cold but engine runs fine until hot then it becomes impossible to
restart the engine untill it cools below operating temp.
The fuel filter will stop crud from getting to your carb jets but the gas
left in the carb from last year has evaporated/changed to crud and is
sitting in the carb and over when you start it next year it will eventually
be drawn into the jets and clog them.
|