Advice needed from someone cleverer than me

[ShaneC]

Righto, as the title suggests I am after a bit of advice from someone cleverer mechanically than yours truly. 99% of folks should be qualified to advise.....

Now I have recently serviced my own outboards (and not for the first time, I get a tech to check them for me once a year and do the difficult stuff), changed the oils, filters and greased propshafts and easy stuff etc etc. Now went to go for a quick spin to Tangas today with the family and lo and behold, one of them decides to play sillys. Started first go as usual, off trailer, mucked around getting the fam on the boat, drove out the leads and she starts coughing, farts and stalls. Went back to the pontoon on my other motor, pulled the fuel system apart to eradicate an air lock, she fired and all was good!! For about 3 minutes.... Gave her a squirt at WOT, went back in picked up family, took off again and same old thing. Now she wont start...

Ok I KNOW its a fuel issue, and I still suspect an air lock or something stupid like that as I drained and replaced all filters during the service. I dont think its an injection issue (otherwise it would start unless all the injectors were dirty/ stuffed) and I cant see how it would be a fuel pump given that I would not think that it would cut in and out and work intermittently. Fuel is fresh and the other motor I serviced is going fine running on fuel from the same pump..... I have it booked in to go on the computer tomorrow but I am trying to avoid that if possible because I know deep down it will reveal nothing relevant to what is going on...

WTF could it be???? Its doing my head in... I am going to have another crack shortly by manually pumping fuel through the entire system with filters off so I know there is fuel getting to the motor, if that fails I am at a loss.

Ideas men?? This needs to be sorted as I have plans and am getting close to a rage out cos I want to go north tomorrow>:( Motor is a Yam F150 4 stroke

Thanks in advance.

Shane

[Aussie123]

You may be getting air in the fuel lines.
You may also have a fuel line delaminating inside and the only way to check is the pull the fuel line off at the primer bulb and check the inside of the hose.

[wirlybird]

primer bulb non return valve issue. Change that see how she goes also use another fuel tank and eliminate the tank as an issue. Great place to start.

If you changed the fuel filter check all the hose connections are tight

[The Woo]

You need to prime the system. Obviously there is air in the line somewhere, and the engine mounted pump is unable to suck it through efficeintly enough.

Just fill your remote filter/s with fuel prior to spinning them on, and use a primer bulb to pump the fuel through. Take the fuel line off on the engine and pump through any air.

[albey]

As a temporary measure run the engine on a separate caddy and fuel line,that will sort out all the peripherals

[Dave71]

Check that the fuel tank breathers are blocked or the hoses are crimped. I got caught out a while back. Engine would run fine to half throttle then would die. Reprimed and off again. It would run clean for around 4-5 min then stop and not restart. Turns out I squashed the braether line when I refitted the tank/floor.

[Spaniard_King]

Shane, Have you changed the sneaky fuel filter between the Low Pressure pump and the vapor seperator it is usually shrouded in a black plastic/ruber shroud and is very slimline. If you have over 400hrs on the engines then this would be an issue.

[ShaneC]

SK, no I haven't mate. I have nearly 900 hrs on mine, but I do have a good mate who is a qualified Yam tech who said he did every possible filter at 500hrs. I think I know the one you are talking about as I always empty my vapour separator every second trip. I shall ring an ask him. If he hasn't, is it a common part that I could pick up easily???

For the record, I have her running again, I went through the fuel system and ensured there was no air in it by manually pushing fuel through with filters off then replacing them. She started after a couple of goes, coughed, farted then stalled, second go she had a cough and then went into its normal smooth idle so I may have nailed it.

I am not banging my thongs together in celebration just yet as i had similar success already today, a run tomorrow will tell the full story. Thank you for your replies guys, and thianks to Brett for the phone call. Geez i hope I have gotten to the bottom of it and can regale all with stories of bigguns come Sunday.

Shane

[Squidlet]

Shane had a similar problem on the weekend,i am def no mechanic and what i did worked weather it was a quick fix or will reocur later.I blew threw the external breather vent a couple of times and away she went! Vapor lock?
This may not help but similar issue!
Cheers Chris.

[Spaniard_King]

SK, no I haven't mate. I have nearly 900 hrs on mine, but I do have a good mate who is a qualified Yam tech who said he did every possible filter at 500hrs. I think I know the one you are talking about as I always empty my vapour separator every second trip. I shall ring an ask him. If he hasn't, is it a common part that I could pick up easily???

For the record, I have her running again, I went through the fuel system and ensured there was no air in it by manually pushing fuel through with filters off then replacing them. She started after a couple of goes, coughed, farted then stalled, second go she had a cough and then went into its normal smooth idle so I may have nailed it.

I am not banging my thongs together in celebration just yet as i had similar success already today, a run tomorrow will tell the full story. Thank you for your replies guys, and thianks to Brett for the phone call. Geez i hope I have gotten to the bottom of it and can regale all with stories of bigguns come Sunday.

Shane

Hope this works http://www.boats.net/parts/search/Yamaha/Outboard/2006%20and%20Later%204-stroke/F150TLR/FUEL%20INJECTION%20PUMP%202/parts.html

Item 16

[ShaneC]

Thanks Garry.... appreciated!

[ShaneC]

Just an update on this one. The motor ran fine on Wednesday so went to Agnes on Thursday for a few days and had no dramas at all. Travelled a long way, used a lot of fuel and caught some good fish. I'll endevour to put up some pics over the next few days. Thanks again to all for their input, if anyone has the same drama after changing filters, if your symptoms are the same as mine, give me a bell because there may be an easy way to fix it....

Cheers