Engine trouble
 

Hi, I have a 75HP, 1992, 3 pistons/2 strokes Mariner engine that
started to give me trouble yesterday. While a was pulling a tube, the
engine suddenly lost power and even at WOT, would not go over 2,600
RPM (while pulling the tube).

I tried the boat alone and even at WOT, the RPM would slowly increase
up to 3,200 and then jolted to 4,000 and then I had to pull the
throttle so it wouldn't go over 5,000 RPM (ie, from 4,000 and 5,000,
the engine was behaving normally). Below 3,200 RPM, the engine noise
is 'deep' and rough.

I had my wife driving the boat while I was watching the engine for any
physical anomaly and couldn't see any. There was no sudden linkage
movement between 3,200 and 4,000 RPM. The butterflies were fully
opened with the throttle at WOT.

The only two things I can think of (and that's just guesses) is there
are two sets of injectors and one kicks in at 3,200 or there is a
second sets of butterflies that opens at 3,200 (but I didn't see any).

I had the injectors cleaned last fall and the engine was running
smoothly until this happened.

Anybody knows what could make the engine behave that way? Or if you
know a better newsgroup/forum to post my question, I'm all ear.

Thanks!

Engine trouble
 

wrote in message
...
Hi, I have a 75HP, 1992, 3 pistons/2 strokes Mariner engine that
started to give me trouble yesterday. While a was pulling a tube, the
engine suddenly lost power and even at WOT, would not go over 2,600
RPM (while pulling the tube).

I tried the boat alone and even at WOT, the RPM would slowly increase
up to 3,200 and then jolted to 4,000 and then I had to pull the
throttle so it wouldn't go over 5,000 RPM (ie, from 4,000 and 5,000,
the engine was behaving normally). Below 3,200 RPM, the engine noise
is 'deep' and rough.

I had my wife driving the boat while I was watching the engine for any
physical anomaly and couldn't see any. There was no sudden linkage
movement between 3,200 and 4,000 RPM. The butterflies were fully
opened with the throttle at WOT.

The only two things I can think of (and that's just guesses) is there
are two sets of injectors and one kicks in at 3,200 or there is a
second sets of butterflies that opens at 3,200 (but I didn't see any).

I had the injectors cleaned last fall and the engine was running
smoothly until this happened.

Anybody knows what could make the engine behave that way? Or if you
know a better newsgroup/forum to post my question, I'm all ear.

Thanks!

Over temp possible. Maybe low oil in the tank.

Engine trouble
 

On Jun 22, 10:47 pm, "CalifBill" wrote:
wrote in message

...



Hi, I have a 75HP, 1992, 3 pistons/2 strokes Mariner engine that
started to give me trouble yesterday. While a was pulling a tube, the
engine suddenly lost power and even at WOT, would not go over 2,600
RPM (while pulling the tube).

I tried the boat alone and even at WOT, the RPM would slowly increase
up to 3,200 and then jolted to 4,000 and then I had to pull the
throttle so it wouldn't go over 5,000 RPM (ie, from 4,000 and 5,000,
the engine was behaving normally). Below 3,200 RPM, the engine noise
is 'deep' and rough.

I had my wife driving the boat while I was watching the engine for any
physical anomaly and couldn't see any. There was no sudden linkage
movement between 3,200 and 4,000 RPM. The butterflies were fully
opened with the throttle at WOT.

The only two things I can think of (and that's just guesses) is there
are two sets of injectors and one kicks in at 3,200 or there is a
second sets of butterflies that opens at 3,200 (but I didn't see any).

I had the injectors cleaned last fall and the engine was running
smoothly until this happened.

Anybody knows what could make the engine behave that way? Or if you
know a better newsgroup/forum to post my question, I'm all ear.

Thanks!

Over temp possible. Maybe low oil in the tank.

Thanks for the very quick reply :-)

However, I tried the engine the next morning while the engine was cool
and it did the same thing. The oil reservoir is about half full.

Engine trouble
 

Engine trouble
 

I think you got the wrong group. This one is alt.loogy.bull****
off-topic.

Engine trouble
 

On Sun, 22 Jun 2008 19:30:16 -0700 (PDT),
wrote:

Anybody knows what could make the engine behave that way?

If the VRO has been acting up, you could have fouled plugs, the carbs
might need cleaning, could be a soft power pack - there are any number
of possibilities with that type of RPM range.

I would suspect either plugs or something along the lines of a power
pack.

Engine trouble
 

On Jun 23, 12:23*am, Larry wrote:
wrote in news:75891839-5d1f-46f6-aa2c-df6033521575
@x35g2000hsb.googlegroups.com:

I had the injectors cleaned last fall and the engine was running
smoothly until this happened.

A '92 Mariner has injectors, not carbs??

Does it have a PRIMER BULB?

Primer bulb on the fuel line? Yes I have one. Now that I think about
it, it has oil injector but probably carburetor...

Engine trouble
 

On Jun 23, 12:30*am, "Eat Me, Trolls" wrote:
I think you got the wrong group. This one is * * * alt.loogy.bull****
off-topic.

Like I said in my original post:

"Or if you know a better newsgroup/forum to post my question, I'm all
ear".

So? Do you have a better one?

Engine trouble
 

Engine trouble
 

On Jun 23, 6:31*am, Short Wave Sportfishing
wrote:
On Sun, 22 Jun 2008 19:30:16 -0700 (PDT),
wrote:

Anybody knows what could make the engine behave that way?

If the VRO has been acting up, you could have fouled plugs, the carbs
might need cleaning, could be a soft power pack - there are any number
of possibilities with that type of RPM range.

I would suspect either plugs or something along the lines of a power
pack.

I'll check the plugs but at idle, the engine runs fine. I would think
a foul plug would show its color more at low RPM.

The transition is ALWAYS at 3,200 RPM. Once it reaches 3,200 RPM (on
the dot), it gets to 4,000 RPM within a fraction of a second (it feels
like a sport car taken off) as if it got the correct air/gas ratio
suddenly.