Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
alfred pettersen
 
Posts: n/a
Default Mercruiser 250 CID 165hp straight 6 problem

I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping" in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is either
"fuel starved" or being "flooded".

Usually, the "fix" involves stopping the engine, opening the engine cover
and pumping the fuel bulb until line pressure is restored, then restarting
the engine and running up to 2000 rpm @ idle, THEN re-engaging the
transmission (which usually behaves normally then).

My mechanic cannot figure it out (without much expensive "diagnosing").
Besides, being the height of the season, I am likely to have to wait till
mid-september before he could run up my bill.

Any ideas?

Bill
Toronto, Canada


  #2   Report Post  
trainfan1
 
Posts: n/a
Default

alfred pettersen wrote:
I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping" in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is either
"fuel starved" or being "flooded".


Gotta figure out which one. It sounds like a fuel bowl level/float
valve problem, maybe in combination with a weak fuel pump and/or vapor
lock. Are you running your bilge blower?

Usually, the "fix" involves stopping the engine, opening the engine cover
and pumping the fuel bulb until line pressure is restored,


I have never seen a primer bulb on a Mercruiser - how did that get
there? This may be part of the problem... you may be sucking air into
the fuel sytem at the clamps, or the check valves are sticking or
broken... the bulb being there at all may be a sign of a previous problem...

Rob
  #3   Report Post  
Butch Davis
 
Posts: n/a
Default

This is an outboard, right? Have you serviced your fuel filter lately? Has
any fuel system work been done recently? Is your fuel tank built in? If
so, perhaps some condensate has accumulated in the bottom and needs removal.
If a portable tank have you tried completely emptying the tank to ensure no
water is present? When did you last replace the primer bulb and or rubber
fuel hoses? Over time these parts can become pretty soft and will suck air.
Sounds to me as though you are getting a dose of water in your carb(s) at a
particular trim angle when barely on plane, ie. a steep trim angle. Thus
the mention of fuel in the tank.

Good luck with the problem.

Butch
"trainfan1" wrote in message
...
alfred pettersen wrote:
I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping" in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is either
"fuel starved" or being "flooded".


Gotta figure out which one. It sounds like a fuel bowl level/float valve
problem, maybe in combination with a weak fuel pump and/or vapor lock.
Are you running your bilge blower?

Usually, the "fix" involves stopping the engine, opening the engine cover
and pumping the fuel bulb until line pressure is restored,


I have never seen a primer bulb on a Mercruiser - how did that get there?
This may be part of the problem... you may be sucking air into the fuel
sytem at the clamps, or the check valves are sticking or broken... the
bulb being there at all may be a sign of a previous problem...

Rob



  #4   Report Post  
trainfan1
 
Posts: n/a
Default

Butch Davis wrote:
This is an outboard, right?


A 250 Cubic Inch 165 hp outboard by Mercruiser? No... this is an I/O
with a Chevrolet-based I-6 engine... which is why I question the
"pumping the fuel bulb" part of the problem...


Have you serviced your fuel filter lately? Has
any fuel system work been done recently? Is your fuel tank built in? If
so, perhaps some condensate has accumulated in the bottom and needs removal.
If a portable tank have you tried completely emptying the tank to ensure no
water is present? When did you last replace the primer bulb and or rubber
fuel hoses? Over time these parts can become pretty soft and will suck air.
Sounds to me as though you are getting a dose of water in your carb(s) at a
particular trim angle when barely on plane, ie. a steep trim angle.



2500-3000 rpm is moving at a pretty good clip with this engine, full-on
plane.

Rob




the mention of fuel in the tank.

Good luck with the problem.

Butch
"trainfan1" wrote in message
...

alfred pettersen wrote:

I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping" in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is either
"fuel starved" or being "flooded".


Gotta figure out which one. It sounds like a fuel bowl level/float valve
problem, maybe in combination with a weak fuel pump and/or vapor lock.
Are you running your bilge blower?

Usually, the "fix" involves stopping the engine, opening the engine cover
and pumping the fuel bulb until line pressure is restored,


I have never seen a primer bulb on a Mercruiser - how did that get there?
This may be part of the problem... you may be sucking air into the fuel
sytem at the clamps, or the check valves are sticking or broken... the
bulb being there at all may be a sign of a previous problem...

Rob




  #5   Report Post  
Gordon
 
Posts: n/a
Default

Never heard of a primer bulb on this engine either. As to 3000 rpm, this
engines top end is 3800 if I remember correctly.
Gordon
"trainfan1" wrote in message
...
Butch Davis wrote:
This is an outboard, right?


A 250 Cubic Inch 165 hp outboard by Mercruiser? No... this is an I/O
with a Chevrolet-based I-6 engine... which is why I question the
"pumping the fuel bulb" part of the problem...


Have you serviced your fuel filter lately? Has
any fuel system work been done recently? Is your fuel tank built in?

If
so, perhaps some condensate has accumulated in the bottom and needs

removal.
If a portable tank have you tried completely emptying the tank to ensure

no
water is present? When did you last replace the primer bulb and or

rubber
fuel hoses? Over time these parts can become pretty soft and will suck

air.
Sounds to me as though you are getting a dose of water in your carb(s)

at a
particular trim angle when barely on plane, ie. a steep trim angle.



2500-3000 rpm is moving at a pretty good clip with this engine, full-on
plane.

Rob




the mention of fuel in the tank.

Good luck with the problem.

Butch
"trainfan1" wrote in message
...

alfred pettersen wrote:

I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping" in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is

either
"fuel starved" or being "flooded".

Gotta figure out which one. It sounds like a fuel bowl level/float

valve
problem, maybe in combination with a weak fuel pump and/or vapor lock.
Are you running your bilge blower?

Usually, the "fix" involves stopping the engine, opening the engine

cover
and pumping the fuel bulb until line pressure is restored,

I have never seen a primer bulb on a Mercruiser - how did that get

there?
This may be part of the problem... you may be sucking air into the fuel
sytem at the clamps, or the check valves are sticking or broken... the
bulb being there at all may be a sign of a previous problem...

Rob








  #6   Report Post  
Butch Davis
 
Posts: n/a
Default

Sorry, missed the part about the CID. The bulb took over my brain. At any
rate, I continue to think of water in the tank as a strong possibility but
other things could also be causing the problem.

If the engine fuel pump is functioning properly I'd lose the bulb. BUT, if
there is water in the tank the bulb could be a way to pump it out.

Did you say the fuel filter/water separator can has been checked for water
and there was none?

Strange problem. Everything I think of is shot down by the narrow RPM range
at which the problem manifests. If you are wave hopping any sediment in the
tank bottom would be stirred up and enter the fuel suction but the filter
should catch it.???

You might want to check the carb and intake mounting and gaskets and
retorque the nuts and screws. It might also help to run a couple of cans of
carb cleaner through the system.

Wish I had more to offer.

Butch
"Gordon" wrote in message
...
Never heard of a primer bulb on this engine either. As to 3000 rpm, this
engines top end is 3800 if I remember correctly.
Gordon
"trainfan1" wrote in message
...
Butch Davis wrote:
This is an outboard, right?


A 250 Cubic Inch 165 hp outboard by Mercruiser? No... this is an I/O
with a Chevrolet-based I-6 engine... which is why I question the
"pumping the fuel bulb" part of the problem...


Have you serviced your fuel filter lately? Has
any fuel system work been done recently? Is your fuel tank built in?

If
so, perhaps some condensate has accumulated in the bottom and needs

removal.
If a portable tank have you tried completely emptying the tank to
ensure

no
water is present? When did you last replace the primer bulb and or

rubber
fuel hoses? Over time these parts can become pretty soft and will suck

air.
Sounds to me as though you are getting a dose of water in your carb(s)

at a
particular trim angle when barely on plane, ie. a steep trim angle.



2500-3000 rpm is moving at a pretty good clip with this engine, full-on
plane.

Rob




the mention of fuel in the tank.

Good luck with the problem.

Butch
"trainfan1" wrote in message
...

alfred pettersen wrote:

I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping"
in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is

either
"fuel starved" or being "flooded".

Gotta figure out which one. It sounds like a fuel bowl level/float

valve
problem, maybe in combination with a weak fuel pump and/or vapor lock.
Are you running your bilge blower?

Usually, the "fix" involves stopping the engine, opening the engine

cover
and pumping the fuel bulb until line pressure is restored,

I have never seen a primer bulb on a Mercruiser - how did that get

there?
This may be part of the problem... you may be sucking air into the fuel
sytem at the clamps, or the check valves are sticking or broken... the
bulb being there at all may be a sign of a previous problem...

Rob







  #7   Report Post  
Jack Redington
 
Posts: n/a
Default

trainfan1 wrote:
Butch Davis wrote:

This is an outboard, right?



A 250 Cubic Inch 165 hp outboard by Mercruiser? No... this is an I/O
with a Chevrolet-based I-6 engine... which is why I question the
"pumping the fuel bulb" part of the problem...


This has to be right. Out first boat had a 165 hp Mercrusier io. (1970
trihull) The thing had more pulling power than a tractor. That 250cid
block would make one tall outboard :-)

I am confused by the primer bulb comment as well..

Capt Jack R..

  #8   Report Post  
alfred pettersen
 
Posts: n/a
Default

The previous owner installed a second 18 US gallon fuel tank and added a
bulb for each tank to prime the line when he switched tanks. When I switch
between tanks and don't prime the line with the bulb, it takes forever for
the fuel pump to pump from the other tank and I use a lot of battery getting
the engine started.

Seems the problem actually originates with a "loose spring" in the carb,
according to my mechanic.

Hitting a good size wave basically knocks the choke partially closed and the
engine sucks to choke closed the rest of the way.

I discovered this weekend that the way to remedy the situation is before
attempting to restart the engine, I put the shifter in neutral and move the
lever forwards a couple of times, then put the lever back where the button
releases and it is ready to put in gear. I restart the engine and voila, no
more hard idling, etc. Seems that priming the engine with the shift lever in
neutral resets the choke and I am "off to the races".

Short of a complete carb overhaul to change out a somewhat tired old spring
(that works 99 % of the time), all I have to do to prevent this condition is
take greater care when approaching another boat's wake. Hitting it head on
and launching my boat over the wake is the principle cause of this engine
condition, but taking the wake at a more progressive angle eliminates the
hard jarring the choke gets and prevents the choke closing.

I might rebuild the carb next year, not sure.

Thanks for all the hints.

Regards
Bill/Cdnviking

"Jack Redington" wrote in message
nk.net...
trainfan1 wrote:
Butch Davis wrote:

This is an outboard, right?



A 250 Cubic Inch 165 hp outboard by Mercruiser? No... this is an I/O
with a Chevrolet-based I-6 engine... which is why I question the "pumping
the fuel bulb" part of the problem...


This has to be right. Out first boat had a 165 hp Mercrusier io. (1970
trihull) The thing had more pulling power than a tractor. That 250cid
block would make one tall outboard :-)

I am confused by the primer bulb comment as well..

Capt Jack R..



  #9   Report Post  
posted to rec.boats
Banned
 
First recorded activity by BoatBanter: Jun 2013
Posts: 1,692
Default Mercruiser 250 CID 165hp straight 6 problem

On Sunday, August 7, 2005 6:59:34 PM UTC-4, alfred pettersen wrote:
I am having an intermitent problem with this engine in my boat.

When I run at around 2500-3000 rpm and do some modest "wave hopping" in
Southern Georgian Bay, occassionally my engine just "dies" (stalls).

When I restart it and give it some throttle, it behaves like it is either
"fuel starved" or being "flooded".

Usually, the "fix" involves stopping the engine, opening the engine cover
and pumping the fuel bulb until line pressure is restored, then restarting
the engine and running up to 2000 rpm @ idle, THEN re-engaging the
transmission (which usually behaves normally then).

My mechanic cannot figure it out (without much expensive "diagnosing").
Besides, being the height of the season, I am likely to have to wait till
mid-september before he could run up my bill.

Any ideas?

Bill
Toronto, Canada


www.marineengine.com

They have loads of those that can help. Stay out of here, this is a ******** filled with political posters and losers , like krause, and his ass buddy Luddite.
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
99 Mercruiser Electrical Problem [email protected] General 13 April 21st 05 08:32 AM
GpsMap 276C NMEA Interface Problem Pascal Goncalves Electronics 3 March 2nd 05 01:02 PM
Mercruiser 898 cooling problem gunny Cruising 3 February 27th 05 01:34 PM
Problem with 3 hp Sears Gamefisher / Tanaka 300 dazed and confuzed Boat Building 5 January 28th 05 02:46 PM
back with a problem now Nancy General 14 August 2nd 03 04:43 AM


All times are GMT +1. The time now is 02:34 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 BoatBanter.com.
The comments are property of their posters.
 

About Us

"It's about Boats"

 

Copyright © 2017