Check that the throttle pump is working well, and if it is check the timing.
Bill

"Michael McKnight" wrote in message
om...
Greetings!

I have a 1990 SeaRay 160 with an Alpha 3.0L 130HP I/O. The engine
seems to rev fine when not in gear but under load I get hesitation. I
push the throttle all the way down and I don't get any sputtering but
the engine will kind of lull for a few moments and then start to rev
up.

I have done what little checking I know how to do. I have taken out
the plugs and inspected them and they all seem fine except for number
2 which has, what I would consider, excessive carbon build-up. I have
not check compression or anything else really as I do not have the
proper tools.

I know this is probably a little vague but I hope someone can help me
out here. I am certainly not opposed to do anything I can myself
before taking it into the shop which is about a 2 month wait!

Is the carbon build-up something to be overly concerned about? The
boat is not used all that often, maybe once a week for a couple of
hours.

Any help would be greatly appreciated!

Thanks!

Mike

Mike wrote:
I have a 1990 SeaRay 160 with an Alpha 3.0L 130HP I/O. The engine seems
to rev fine when not in gear but under load I get hesitation. I push the
throttle all the way down and I don't get any sputtering but the engine
will kind of lull for a few moments and then start to rev up.
I have done what little checking I know how to do. I have taken out the
plugs and inspected them and they all seem fine except for number 2
which has, what I would consider, excessive carbon build-up. I have not
check compression or anything else really as I do not have the proper
tools.
I know this is probably a little vague but I hope someone can help me
out here. I am certainly not opposed to do anything I can myself before
taking it into the shop which is about a 2 month wait!
Is the carbon build-up something to be overly concerned about? The boat
is not used all that often, maybe once a week for a couple of hours.
Any help would be greatly appreciated!
Thanks!
Mike
==================================
This could be a weak set of breaker points. I had this problem with my
1988 5.0 OMC a few years ago. Turned out to be a cheap point set. I
couldn't find the marine points when I was tuning up, so I used a set of
generic points. Bad idea!! The spring is no where near as strong as
the proper points. The weak spting allows the points to "flap" a bit.
So when I replaced with Borg-Warner points, the boat almost leaped out
of the water. I just did a complete tune up using OMC points,
condenser, cap, rotor and new Champion plugs. The boat has never ran
better. Its purring like a kitten,,,, (now if I could just get it
purr like a boat.....:-)
========
Norm

Calif Bill wrote:
: Check that the throttle pump is working well, and if it is check the timing.
: Bill


Good advice.

I had the same problem on a 3.8L OMC. Throttle pump but when I asked the
repair guy what could cause it, he also mentioned timing.

The MTBE in gas doesn't like throttle pumps a whole lot.

b.