help please. outboard cutting out - Page 2

charliee · 08 May 2018, 09:28

+ 1 for fuel pump, but check the bottom of the tank thru the sender and change the filter.
good luck

Striker · 08 May 2018, 09:48

Quote:

Originally Posted by jeffstevens763@g

fuel pump?

Hi Jeff,

Personally I wouldn’t expect a fuel pump to cause an excessive vacuum in the line (Crush the bulb) unless the system couldn’t keep up with the demand.

I would have thought that a weak pump would indeed cause fuel starvation, but if the fuel supply before the pump was ok then the bulb wouldn’t collapse.

Just a personal opinion, but my thoughts are that the issue is between the pump and atmosphere.

Have been known to be wrong though [emoji15]

Pikey Dave · 08 May 2018, 11:16

My money would be on crap in the tank getting sucked into the pickup. Faulty primer bulb would have been the first port of call, but the OP has eliminated that & the tank vent. The only thing left is blockage between tank & primer bulb.

jeffstevens763@g · 08 May 2018, 12:25

Could be non return such in bulb

arkamelis · 08 May 2018, 21:42

has your aware i couldn't get it to fire over last night once it cut out, luckly i managed to flush the outboard before it did.

So today went and borrowed a 25ltr yamaha tank, filled it with a tanners worth of fuel, got to the boat and connected the outboard fuel line to yamaha fuel plug, didn't bother with a primer bulb, as i thought the distance was short and i would have thought the outboard would have sucked it up the short distance.pluged it into the yamaha tank, turned the engine over and after 15 seconds of it turning and me pushing the choke it fired over and started

so while running i continued flushing as it was still in the water tank and 20mins later still running, i kept the revs at around 1000 and occasionally come of the throttle and let it run at around 600-700 revs, again didn't cut out "yes result" but there is still one thing worrying me, after it let me down the weekend when i was out at exmouth is it possible it might be cutting out when its on the water and hits around 2000-2200revs like it did to start with. again when i was out the weekend it did start and it did run must of the time going slow.
Anyway im really pleased its running again, and i can now start the process of stripping down the fuels system/pipes/filter,inspect tank and just buy a new primer bulb.
i was thinking whether the fuel system isn't the right set up, but originally the boat would have had a Force 120hp 2 stroke on the back when they came over so i would have guessed the set up is ok, just that theres a fault within it somewhere
I have took onboard all your advice and recommendations and the next opportunity i will carry out all the tests to find the culprit

Happy chappie Matt

jeffstevens763@g · 08 May 2018, 21:56

I would run in real time to make sure a 1000 revs isn't a lot of fuel demand OMO

arkamelis · 09 May 2018, 22:25

been to boat today and inspected tank, removed sender unit and took look inside, there was some debris in there, not a lot though, some of it was down to me when i inspected the tank when i got the boat. when i refitted the sender unit back the very first time i used saba and quite a lot to make sure it was a good seal, thing was has it compressed some squirted internally around the inside and i think over time the fuel was breaking it down into what i can only call jelly, but black.
if i was to give some idea has to how much debris was in there" on the bottom of thank" i would say it would cover the bottom of a milk top " 4 pint milk top" so again not a lot. i also checked the pick up pipe and it was clear, there was also a mesh cover on the bottom of the pick up pipe.
i was thinking of getting one of these hand operated extraction pumps for fuel and emptying all the fuel/debris out then refill with the fuel once i have run it through a filter " pair of tights"folded a few times, hopefully this will rule the tank out then. my next step is the fuel filter and all hoses.
keep you posted

arkamelis · 09 May 2018, 22:33

oh the tank on the inside was mint, no discolouration, fuel was crystal clear, side of the tank shiny.

just a thought, was thinking of a way around having to empty the tank, i i was thinking of putting a slight bend on the pick up pipe, to lets say raise it about a inch from the low point its at now. means i will always have fuel in the tank, but it would help not suck up any debris thats on the bottom of the tank ?

beamishken · 09 May 2018, 22:50

If you have sealer thats turned to a jelly like consistency my money would be on that being your problem
The bits get naturally drawn to the pickup and collect around the filter eventualy blocking it
Once there is no flow they settle back to the bottom of the tank
Id attempt to clean as much out as possible then i think id remove the gauze on the pickup and fit a temporary inline filter that way when you get debris in the filter you can see it and easily remove the filter rather than blocking the main filter or the pickup gause neither of which you can see.
Those inline filters are pennies on ebay if you buy a bag of 10 or 12

willk · 09 May 2018, 22:56

Quote:

Originally Posted by arkamelis

just a thought, was thinking of a way around having to empty the tank, I was thinking of putting a slight bend on the pick up pipe, to lets say raise it about a inch from the low point its at now. means i will always have fuel in the tank, but it would help not suck up any debris thats on the bottom of the tank ?

IMO, absolutely not! I'd say better to suck up any crud and rely on the filters to catch it. Keep a spare filter and strap onboard. When the boat bounces around - any debris on the base of the tank will rise into suspension and cause issues. Same with water - better caught in the filter bowl and released rather than lying in the tank and causing issues.

arkamelis · 09 May 2018, 23:38

thanks guys

i will buy the fuel extracter pump and empty the tank and any debris, at the same time i will remove the big fuel filter above the tank and inspect that to see if anything has gone up, clean it and refit it.
i have also ordered a new yamaha primer bulb, so hopefully in a few weeks it should be a good clean system.
most of the fuel lines are new, i had to put new ones on for the BSS certificate, i think the only hose left will be the fire hose that goes the the small vent back of the boat. which brings me to another concern, with portable tanks you have a air release screw on the cap, but there isn't any air realise screw on my fixed tank which makes me think the air must be drawing from the fire vent back of the boat, if that is the case, could fuel vapour restrict good air coming in to release vacuum/pressure ?

beamishken · 10 May 2018, 06:58

The fitting your talking about at thr back of The boat is the vent and should be working fine.
In any case it takes a long time of running to create a vacuum in the tank of sufficient pressure to stop fuel flow. If you crack the fuel cap when it cuts out and you hear air rush in then you have a vent problem

Iron Dials · 10 May 2018, 10:12

Could you push air backwards through the fuel line to the pick up? Just to clear any embedded crud, when you empty the tank.
This would also help trouble shoot whether you have a blockage in the feed line. I assume this would have to be without the primer bulb inline.

(In the absence of a compressor I have used a bicycle pump+tape to back pressure a blocked dishwasher. So it doesn't need heavy machinery to achieve it)

arkamelis · 10 May 2018, 21:33

Hi to all
been back to boat again today to inspect the fuel filter, turns out to be fuel filter and water separator. Anyway crystal clear and not a speck of dirt inside.

So i started on the next task of inspecting all the hoses and fitting and what i come across was a bulk head fitting, So the main fuel outlet hose goes into the big filter and from there comes up to a fitting in the bulk head and is attached with jubilee clip, fuel then passes through fitting in bulk head to the outboard well where i fit another hose with the primer bulb then the outboard hose attaches to the primer bulb. So thats the set up

so all of the fittings and hoses are all 8mm, but when i inspected the bulk head fitting i noticed the diameter was smaller, measured it and its a 6mm fitting

which kind of explains why when i was increasing the throttle the demand for fuel was being restricted as it was passing through this 6mm fitting, and this is why the primer bulb was sucked try. also when i disconnected the primer bulb and i just took the outboard fuel line and fitted it straight to this bulk head fitting and it done the same thing just kept cutting out. i think this v4 needs the juice and just wasn't getting it running through a 6mm bulk head fitting

arkamelis · 10 May 2018, 21:36

i do hope this is right or im gonna look well stupid

arkamelis · 10 May 2018, 21:40

this is the bulk head fitting

arkamelis · 10 May 2018, 21:50

Quote:

Originally Posted by beamishken

The fitting your talking about at thr back of The boat is the vent and should be working fine.
In any case it takes a long time of running to create a vacuum in the tank of sufficient pressure to stop fuel flow. If you crack the fuel cap when it cuts out and you hear air rush in then you have a vent problem

hi beamishken
thank you, i wasn't 100% sure it was a vent because i had a boat inspection carried out to use it on inland waterways ( BSS ) boat safety scheme )
and the guy said it had something to do with if the tank goes up into flames, that this fitting help flare the flames out to the back of the boat. saying that if the tank did go up into flames, i guess i wouldn't hang around to see this

So vent it is

and yes its working well, all striped down cleaned and plenty of air blowing straight through
There was also concerns about where the vent was at the back of the boat as it is quite low and close to outboard, the concern was with transom waves posing water into vent and it finding its way to the tank.but after inspecting the vent, its actually well designed with a barrier around the opening and on the inside theres a mesh screen. i have today relocated the hose at the back and routed it much higher up than what it was, so its now about the hight of the main fuel filler cap

Striker · 11 May 2018, 14:40

As a sanity check you could always fit a primer bulb to the top of the hose (outboard end) and manually pump the fuel into a container. If you still have a restriction the original primer bulb will collapse. If you have cured it there will be tons of flow and no decompression of the original bulb. With a length of spare hose you could use this to syphon the tank ( pulling it through the filter before you change it has the added benefit of filtering before its reused!) then use it as a mini vacuum through your sender unit to suck up the bits. No need to spend on a pump!

arkamelis · 11 May 2018, 17:39

nice idea striker.

will do what you have recommended, like you say saves having to buy a pump. was thinking as well, i was going to buy another bulkhead fitting, but this time a 8 or 10mm fitting, but i was thinking i could just make the hole bigger and just put the hose through rather than having this fitting at all

Striker · 11 May 2018, 17:47

I’m not convinced that fitting is your problem. If your bulb was compressed after running its much more of a blockage than that. It would re inflate almost as soon as you throttle back. 6mm would be more than enough flow at anything other than flat out!
Personally I would clean out everything then see how much flow you can get through by sucking through the line (using the primer). My 140hp Suzuki burns 22 Ltrs an hour on full load. That’s only really a trickle through a pipe!