Previous in Forum: SEW Motors New DRS Motors   Next in Forum: Need Advice on Rebuilding the Niles Spindle
Close
Close
Close
29 comments
Rate Comments: Nested
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962

Outboard Engine Cutting Out

10/27/2009 3:21 AM

At a place where I go, one of the engines keeps cutting out. It is a 40hp (mercury I think) attached to a RIB. When it is when it is idling it is fine, but when you try to drive it slowly, it cuts out. It is fine once you get it going faster. Do you think it could just be a case of rubbish in the carb? Its a 2 stroke.

__________________
bondy111
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#1

Re: Outboard engine cutting out

10/27/2009 6:40 AM
  • Rubbish in the carb?
  • Faulty magneto or LT leads?
  • Faulty HT lead?
  • Faulty spark plug or gap too wide or electrodes oily?
  • Spark plug not screwed in properly?
__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#2
In reply to #1

Re: Outboard engine cutting out

10/27/2009 7:34 AM

Rabbits foot degraded by exposure to excess moisture?

__________________
health warning: These posts may contain traces of nut.
Register to Reply Off Topic (Score 5)
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#3
In reply to #2

Re: Outboard engine cutting out

10/27/2009 8:14 AM

D'oh!

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply Off Topic (Score 5)
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#7
In reply to #1

Re: Outboard engine cutting out

10/27/2009 1:57 PM

The spark plug is seated properly, the gap is too wide, and it is clean. I think the HT lead is ok, but have not had time to check. I will check the carb when I can, but am a bit run off my feet at the moment.

__________________
bondy111
Register to Reply
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#15
In reply to #7

Re: Outboard engine cutting out

10/28/2009 4:20 AM

"the gap is too wide" The gap is not too wide*

__________________
bondy111
Register to Reply
Anonymous Poster
#9
In reply to #1

Re: Outboard engine cutting out

10/27/2009 10:32 PM

I would say the low speed jets are plugged up a bit. either remove and clean the carburetor or run some carb cleaner with the fuel. These engines need to be run fast, the 2 cycle engines do not run well at low speed.

Also, check the fuel and see that it is fairly new, old fuel will gum up fuel lines, carburetor jets, and other items that are meant to be cleaned.

Al

Register to Reply
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#4

Re: Outboard Engine Cutting Out

10/27/2009 9:17 AM

I'll go with rubbish in the carb/s. For us Yanks, what's a RIB?

Register to Reply
Power-User
Engineering Fields - Piping Design Engineering - New Member Engineering Fields - Mechanical Engineering - New Member

Join Date: Aug 2008
Location: Europe
Posts: 287
Good Answers: 27
#5
In reply to #4

Re: Outboard Engine Cutting Out

10/27/2009 10:39 AM

"Rigid Inflatable Boat"

The hull has a solid bottom with inflatable sides

__________________
Best regards, HeviiGuy
Register to Reply
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#6
In reply to #5

Re: Outboard Engine Cutting Out

10/27/2009 10:42 AM

What'll they think of next? Isn't that (Rigid Inflatable Boat) an oxymoron?

Register to Reply
Guru
Hobbies - DIY Welding - Wannabeabettawelda

Join Date: May 2007
Location: Annapolis, Maryland
Posts: 7940
Good Answers: 458
#10
In reply to #6

Re: Outboard Engine Cutting Out

10/27/2009 10:39 PM

Sometimes referred to as a RHIB. Rigid Hull Inflatable Boat but it's pronounced 'rib'.

http://www.zodiaccz7.com/

Cheers!

Register to Reply
Anonymous Poster
#8

Re: Outboard Engine Cutting Out

10/27/2009 10:32 PM

The US military uses a lot of RIB's. They are almost unsinkable and can be stored in little space when deflated.

Register to Reply
Guru

Join Date: Feb 2006
Location: Piney Flats, Tennessee
Posts: 1740
Good Answers: 23
#11

Re: Outboard Engine Cutting Out

10/27/2009 11:51 PM

Are you using fresh fuel ?

Gas Mix Fuel setting on a boat for a long time is like desiel fuel takes a hot spark to burn it or a very warm motor.

__________________
If you never do anything you never have problems.
Register to Reply
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#12

Re: Outboard Engine Cutting Out

10/28/2009 2:34 AM

Yes, the fuel is fresh, and yesterday after driving it for about 10 minutes, as I was driving in towards the jetty, and minimum rpm in forwards, it cut out again.

__________________
bondy111
Register to Reply
Anonymous Poster
#13

Re: Outboard Engine Cutting Out

10/28/2009 3:56 AM

Oil mixed in with the gas or oil injection? Too Much oil???

Register to Reply
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#14
In reply to #13

Re: Outboard Engine Cutting Out

10/28/2009 4:19 AM

Oil mixed with the petrol. There isn't too much oil, the other 4 2stroke engines are working perfectly. They are 2 25hp, 15hp, 10hp.

__________________
bondy111
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#28
In reply to #14

Re: Outboard Engine Cutting Out

11/01/2009 12:47 PM

Different engines sometimes need different mix percentages.....I think that was what was implied.....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#29
In reply to #28

Re: Outboard Engine Cutting Out

11/02/2009 1:37 AM

Oh ok. Thanks.

__________________
bondy111
Register to Reply
Active Contributor

Join Date: Sep 2009
Location: UK
Posts: 19
#16

Re: Outboard Engine Cutting Out

10/28/2009 4:47 AM

Check the vent on the fuel tank - might be blocked

__________________
The Skin is mightier than the Banana
Register to Reply
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#17
In reply to #16

Re: Outboard Engine Cutting Out

10/28/2009 4:56 AM

The vent is ok on the fuel tank; there are 2 fuel tanks for it, and the problem occurs with both. Also, the problem is not in the fuel line.

__________________
bondy111
Register to Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#18
In reply to #17

Re: Outboard Engine Cutting Out

10/28/2009 5:08 AM

Is the ignition timing adjustable?
Del

__________________
health warning: These posts may contain traces of nut.
Register to Reply
Anonymous Poster
#19

Re: Outboard Engine Cutting Out

10/28/2009 5:57 AM

Next time it happens, quick like a bunny rabit pull a spark plug and tell us exactly how it looks. Is it wet? Black? Brown? white and chalky? Do this the instant it dies not after you have cussed it, restarted it, and then blown the carbon out of it. OK, you can cuss it first but don't restart it.

Register to Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16512
Good Answers: 670
#20
In reply to #19

Re: Outboard Engine Cutting Out

10/28/2009 6:13 AM

Hey man, if your Bunny Rabbit can pull spark plugs he should join this forum. We need all the furry critter we can get.
Del

__________________
health warning: These posts may contain traces of nut.
Register to Reply Off Topic (Score 5)
Power-User
United States - Member - New Member Engineering Fields - Biomedical Engineering - Radiation Oncology Engineering Hobbies - Fishing - New Member APIX Pilot Plant Design Project - Member - New Member Hobbies - Hunting - New Member Hobbies - DIY Welding - New Member Hobbies - Target Shooting - New Member Popular Science - Biology - New Member

Join Date: Sep 2006
Location: CT
Posts: 267
Good Answers: 1
#21

Re: Outboard Engine Cutting Out

10/28/2009 7:37 AM

I had a similar problem with an older 9.9 Yamaha engine. Only at slow idle. I put the fuel tank up on the seat and the engine ran better at slow speed. I think it the suction the engine imparts on the incoming fuel line is insufficent. Maybe a pin hole leak in the line or a clamp not tight enough.

Good luck

__________________
“Sometimes we don't even realize what we really care about, because we get so distracted by the symbols.” ? Tom Wolfe, The Electric Kool-Aid Acid Test
Register to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#22
In reply to #21

Re: Outboard Engine Cutting Out

10/28/2009 10:17 AM

That one might also indicate a partially-blocked fuel filter, making it run lean at low revolutions. It's worth checking, anyway, and renewing it is a simple thing to do.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Anonymous Poster
#23

Re: Outboard Engine Cutting Out

10/28/2009 1:01 PM

Besides the carburetor there is a little lever attached to a linkage on the throttle, it selects between fixed speed (i.e. for a lawn mower) or adjustable throttle (for a go-kart).

Hopefully you just switched it unadvertently. Otherwise try cleaning your carb.

Yahlasit

Register to Reply
Guru
United Kingdom - Member - British

Join Date: Nov 2007
Location: Gloucestershire, England
Posts: 962
#24

Re: Outboard Engine Cutting Out

10/28/2009 2:29 PM

I had a thought, what if I turned the idle speed up, so if it is going slightly faster, it may not stall.

__________________
bondy111
Register to Reply
Guru

Join Date: Jul 2006
Location: CA (Central Arkansas, USA)
Posts: 599
Good Answers: 10
#25

Re: Outboard Engine Cutting Out

10/28/2009 3:44 PM

On the Mercs I've worked on the ignition components move as the throttle is pushed until the max advance stop is reached. Check for frayed wires or wires broken under the insulation. -- JHF

__________________
If it's too good to be true, it probably isn't
Register to Reply
Anonymous Poster
#26
In reply to #25

Re: Outboard Engine Cutting Out

10/28/2009 10:38 PM

And always remember 2 strokes are not happy unless you are wailing the snotskies out of them. They are not lazy 4 strokes that get cranky when you beat on them with the rpm stick.

Register to Reply
Active Contributor

Join Date: Jul 2009
Posts: 23
#27

Re: Outboard Engine Cutting Out

10/30/2009 1:30 PM

If you have the older style mercury 40 hp 2 cylinder replace the stator if you have the newer 3 cylinder replace the CDI box

Knowing is half the battle

Register to Reply
Register to Reply 29 comments
Copy to Clipboard

Users who posted comments:

alonzo200 (1); Andy Germany (1); Anonymous Poster (6); BoltIntegrity (1); Bondy111 (7); Brave Sir Robin (1); Circuit Breaker (1); dadw5boys (1); lyn (2); moore (1); PWSlack (3); rlindey (1); user-deleted-1105 (3)

Previous in Forum: SEW Motors New DRS Motors   Next in Forum: Need Advice on Rebuilding the Niles Spindle
You might be interested in: Cutting Services

Advertisement