Mercruiser 5.7 problems for a newbie
 

..
Got a 21" SeaRay with a 5.7L 260hp mercruiser. It's run fine all year at
least 25 hours, even without a tune-up this year. I try to sell it today
and the guy takes it out and it nearly need towed back in. It idles ok, but
when engaged in gear, bogs down and stalls if you don't give it nearly Full
throttle right off the bat. Tried new gas but not dry gas. I know it has a
Water/Fuel filter on the front right of the motor. I haven't even looked at
it yet really, but I'll change the plugs and look at the distributor. Does
it have a separate fuel filter? Any advice for this total moron would be
highly appreciated because the guy wants to buy the boat if the problem
isn't major. Thanks, Scott

Scott,

You didn't say what year, but if it has a carburetor there is a small fuel
filter inside where the fuel hose connects to the carburetor. Doesn't
sound like a fuel filter problem though, because that would likely show
up as stumbling and stalling at full throttle.

Sounds like a carburetor problem to me. (I'm going based on idles fine,
but stalls under load at low RPM). _Maybe_ the intermediate jets plugged.

I'd also check to make sure the timing hadn't slipped, and that the timing
advance is working.

Good luck with it,

Don W.

SJ wrote:

.
Got a 21" SeaRay with a 5.7L 260hp mercruiser. It's run fine all year at
least 25 hours, even without a tune-up this year. I try to sell it
today and the guy takes it out and it nearly need towed back in. It
idles ok, but when engaged in gear, bogs down and stalls if you don't
give it nearly Full throttle right off the bat. Tried new gas but not
dry gas. I know it has a Water/Fuel filter on the front right of the
motor. I haven't even looked at it yet really, but I'll change the
plugs and look at the distributor. Does it have a separate fuel
filter? Any advice for this total moron would be highly appreciated
because the guy wants to buy the boat if the problem isn't major.
Thanks, Scott

Don, it's an "1981" model.

You didn't say what year, but if it has a carburetor there is a small fuel
filter inside where the fuel hose connects to the carburetor. Doesn't
sound like a fuel filter problem though, because that would likely show
up as stumbling and stalling at full throttle.

Sounds like a carburetor problem to me. (I'm going based on idles fine,
but stalls under load at low RPM). _Maybe_ the intermediate jets plugged.

I'd also check to make sure the timing hadn't slipped, and that the timing
advance is working.

Good luck with it,

Don W.

SJ wrote:

.
Got a 21" SeaRay with a 5.7L 260hp mercruiser. It's run fine all year at
least 25 hours, even without a tune-up this year. I try to sell it
today and the guy takes it out and it nearly need towed back in. It
idles ok, but when engaged in gear, bogs down and stalls if you don't
give it nearly Full throttle right off the bat. Tried new gas but not
dry gas. I know it has a Water/Fuel filter on the front right of the
motor. I haven't even looked at it yet really, but I'll change the
plugs and look at the distributor. Does it have a separate fuel
filter? Any advice for this total moron would be highly appreciated
because the guy wants to buy the boat if the problem isn't major.
Thanks, Scott

A 21" SEA RAY ?!?!? Gosh, I knew they made boats small enough to tow behind a small SUV, but you could pull that one behind a kid's tricycle...and I'll bet it really boogies with that 260hp engine. :)

Hope you find the problem.

"SJ" wrote in message ...
.
Got a 21" SeaRay with a 5.7L 260hp mercruiser. It's run fine all year at least 25 hours, even without a tune-up this year. I try to sell it today and the guy takes it out and it nearly need towed back in. It idles ok, but when engaged in gear, bogs down and stalls if you don't give it nearly Full throttle right off the bat. Tried new gas but not dry gas. I know it has a Water/Fuel filter on the front right of the motor. I haven't even looked at it yet really, but I'll change the plugs and look at the distributor. Does it have a separate fuel filter? Any advice for this total moron would be highly appreciated because the guy wants to buy the boat if the problem isn't major. Thanks, Scott

Motor fired up perfectly today without me doing anything to it. Somethink
must have had moisture in it yesterday. Thanks for the replies.
Scott

It's going to be the accelerator pump in the carb. if it is a
carbureted engine. One of my boats did the same thing.





On Tue, 19 Jul 2005 22:58:12 -0400, "SJ" wrote:

.
Got a 21" SeaRay with a 5.7L 260hp mercruiser. It's run fine all year at
least 25 hours, even without a tune-up this year. I try to sell it today
and the guy takes it out and it nearly need towed back in. It idles ok, but
when engaged in gear, bogs down and stalls if you don't give it nearly Full
throttle right off the bat. Tried new gas but not dry gas. I know it has a
Water/Fuel filter on the front right of the motor. I haven't even looked at
it yet really, but I'll change the plugs and look at the distributor. Does
it have a separate fuel filter? Any advice for this total moron would be
highly appreciated because the guy wants to buy the boat if the problem
isn't major. Thanks, Scott