Mariner fuel problem

Ribald · 27 April 2003, 17:47

Hi folks,

I have been having some probs the fuel supply to my Mariner 60 ELPTO engine the cause of which has, so far, eluded me.

At high speed running above 1500rpm there are no problems at all. However, after a period of say 30-45 mins low speed running below 1500rpm (i.e from harbour entrance to marina at 4 knots - speed limit of 8 knots in force but the boat does not like that speed) the engine will suddenly die. The cure is to pump the primer bulb (which is quite soft) to get fuel back to the engine. All is then OK. I have an under-deck tank with fuel filter in the consol.

I get the impression that the engine fuel pump is not happy at low revs but, before I go down that route, I thought I would ask if anyone else has had similar problems and if so, what was the cure. Are there non-return valves in the primer bulb which could have failed?

Thanks in advance for any help.

David Hickman · 27 April 2003, 17:51

Stating the obvious but I presume that the in line fuel filter has been changed recently?

Ribald · 27 April 2003, 18:13

Yes, last summer. The prob. occured both before and after the change.

jwalker · 28 April 2003, 00:40

The primer bulb does have valves but they're unlikely to be the problem. The fuel pump also has them - more likely. You could be sucking a tiny bit of air which a fast running pump could cope with - not so likely. Pump diaphragm perforated or stiffened up with age - more likely.

Hope this is of help.

JW.

Jizm · 28 April 2003, 05:39

It does sound like it is sucking air in at low throttle but usually that would manifest at all throttle levels. I agree with jwalker about the pump diaphragm. I had a yam that did a similar thing but that also used to lose a bit of throttle response from time to time, found to be a dodgy tank vent so that is also worth checking out but probably unlikely.

Julian · 29 April 2003, 12:35

Hi There

Check the fuel lines for any small holes. We had the same problem years ago and it was a pin prick hole that was sucking in air and at full revs everything was fine but below 1500 the engine would die.

Julian

Tiger · 29 April 2003, 13:10

This may be a bit unlikely, but what oil mix are you using?

At low speeds the plugs may be getting coated to the extent they give up. Do you get lots of smoke??

I used to use a Mariner 60 in the early 90's and the local engineer advised double oil as same block had seized on a few others of the type.
Great at speed, trolling OK but 5-10 mins at tickover and it died.

Needed a good run to clean it out, which it got !!!

Tiger

jace · 29 April 2003, 15:27

Peter

Several things you can try if you think it’s a fuel supply problem.

The first is the filler cap has the integral breather incorporated, open the cap and you can unscrew the screen to check it’s free from debris.

Worth also leaving the cap open slightly to see if that cures the problem, only ever had one faulty unit but it’s worth a go, was having a similar problem to you so worth a go.

Failing that if you think its sucking air, which is pretty unlikely, fit a temporary clear piece of hose between the engine connector and the fuel line. If it is sucking air bubbles will appear in the pipe.

J

Brian · 29 April 2003, 15:57

My 10p is on air getting into the fuel line.
Take a spare tank and use IT'S line to connect to your engine.
That's not an absolute answer but it is a good clue!
Had exactly this problem on my Avon 6.2 with a 130 Honda.

Stuart Mecham · 29 April 2003, 16:02

I found this Site to be useful + tips on OB problems

http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi

Ribald · 29 April 2003, 19:19

Hi again folks,

Thanks very much for all your input to-date regarding my little fuel problem – all very much appreciated.

I am due to take the boat out again this coming weekend so I will run through the various points suggested. I though that I would also but a new portable tank with new fuel lines and primer bulb and try that out. Hopefully that will determine whether the engine is the problem or the boat’s existing fuel supply system. (Jace – I did take all the filler pipes apart recently to get the battery out

and checked over the cap – seemed OK)

I also had a chat with Andy Clark of The Bosun’s Mate (www.bosunsmate.co.uk) whose first question was “When was the fuel system last serviced?” My answer, I’m afraid, was “Ahhh”

. He did think that the problem was probably with the fuel pump, either the check valves or the diaphragm split or gone hard. (Well done JW) He is sending me a service kit for the pump which, he recommends, is done every year along with the water pump impeller. He also said that the carbs/float chambers may be gummed up with crud from old oil laying in there over winter when the petrol has evaporated.

Tiger, thanks for your comments on the mixture – unfortunatley the engine adds it’s own oil so I can’t adjust the mix.

Stuart, thanks for the link – looks like a few hours are needed to trawl through the posts.

Will report back next week – once again, many thanks for the info so far.

Charles · 29 April 2003, 19:36

Top man is Andy Clarke - I will recommend him to anyone at anytime. Please don't forget to come back to this thread and update us once you have resolved the problem.

John Kennett · 29 April 2003, 19:57

Quote:

Originally posted by Ribald
I also had a chat with Andy Clark of The Bosun’s Mate (www.bosunsmate.co.uk) whose first question was “When was the fuel system last serviced?”

Andy would ask that, wouldn't he!

He does know his stuff though (he is so thorough it borders on being aggravating!), and I would certainly pay close attention to his suggestions.

John

Ribald · 07 May 2003, 21:10

With the help of a new portable tank & line, I have managed to establish that my problem lies in the engine and not the boat's fuel system.

After a quick blast she cut out again after 10mins of slow running so now I will have to get round to servicing the fuel pump.

Watch this space.

David Perry · 08 May 2003, 20:53

Ah haaa! another one with a spurious 60ELPTO Mariner problem.
Do NOT say this too loud, someone might hear.....
Similar problem experienced with M60ELPTO a couple of years ago. Many,expensive, trips to "local" engineer, several large bills later, no joy.
Eventually found a trusted dealer who almost iommediately diagnosed a faulty fuel pump.
So the story goes,(Allegedly, I repeat Allegedly there was a batch that mariner knew about, and were less than 100%. Was this an urban myth?
Nealry got to the stage where mariner would be asked to pay a good faith amount of the replacement as engiine was just 2 months outside warranty.Anyway, new pump fitted, job done.
NOW have Mariner 60 4s Efi, good too.
Hope this helps.

NB.
Info re pump was 99th hand!! and is possibly a myth. Have very good things to say about Marier and Barrus.
DP

Ribald · 08 May 2003, 21:40

Cheers David,

I was thinking along the same lines if the service kit does not work. My engine is a 2000 model - seems about right

David Perry · 10 May 2003, 21:18

Yup, seems about right.
One lesson I have learned is....get an auxilliary.
I have a "get out of s**t unit that will see me to land as long as I dont have to contend with big tide races. Then again if all is in the wrong direction I can call for a pint of the balckstuff in Eire!!
Good luck/bon chance/pob hwyl with the engine.
Dave