stevefish Posted November 19, 2015 Share Posted November 19, 2015 i have a tinny, fuel tank permanently fitted @40l, i rarely use more than 20 in a day. last week i did a couple of engine hours, i put about 5l in earlier in the week, and 10 more last night, it appeared full with fuel coming up the clear filler hose. today i did a couple of hours running around downrigging idling etc, i would have estimated 15 litres used 20 max. just near the spit on the way in, she starts running poorly the conks out.. fuel primer bulb is soft. So , i unstrapped the tank, jammed a surfer joe under the other end to get all the fuel to the pick up end, and just make it back to to ramp. again the motor is struggling. So, on the way home into the servo and guess what only 10 litres goes in??? whats gone wrong??? happy to hear ideas theories or anyones experience. mother of all airlocks? blockage in a fuel line? ps, middle harbour is chocolate,the harbour is dirtier than a week ago. squid are fussy, and scored a 70cm king on a dead squid head while the live yakkas went untouched. Link to comment Share on other sites More sharing options...
Guest 4myson Posted November 19, 2015 Share Posted November 19, 2015 Do you have a breather hose fitted ??? Link to comment Share on other sites More sharing options...
stevefish Posted November 19, 2015 Author Share Posted November 19, 2015 Yes Link to comment Share on other sites More sharing options...
njsconst Posted November 19, 2015 Share Posted November 19, 2015 I would have said breather as well. For the sake of $10 replace the primer bulb. I had a similar issue with one of my motors and it was the primer. Link to comment Share on other sites More sharing options...
stevefish Posted November 19, 2015 Author Share Posted November 19, 2015 Thanks for the input so far, I will add that everything has been in place and working for yeat Link to comment Share on other sites More sharing options...
amkr Posted November 19, 2015 Share Posted November 19, 2015 ^ perfect time for something to fail then. I love it when people say "working fine for years", because thats generally how things break Link to comment Share on other sites More sharing options...
stevefish Posted November 19, 2015 Author Share Posted November 19, 2015 Yeah, I thought it was worth stating its a failed element in a design that works rather than something that never worked. I'm thinking the primer could be the culprit. Link to comment Share on other sites More sharing options...
jeffb5.8 Posted November 19, 2015 Share Posted November 19, 2015 Mine was the primer bulb so I spent the $35 and bought a new hose and primer bulb from a marine shop. Link to comment Share on other sites More sharing options...
Geoff Posted November 20, 2015 Share Posted November 20, 2015 It is normal for the primer bulb to be soft once the motor is running . When the problem occurred , did u squeeze the bulb , did it go hard ??. What was the effect on the engine performance , ran ok for a while or made no difference Whilst it may be the primer bulb , if the valve fails it does not prime. Very rarely does the valve close especially when the motor is running. You don't mention if there is a fuel filter fitted. Most motors have two , one in the fuel line between the tank & the motor & another one under the cowling just next to the fuel pump . These should be checked , cleaned , and , or replaced first . The other item to check is water in tank or the filler bowl next to the fuel petrol pump Prior to spending yr $$$$ , by pass the primer bulb. If the motor runs ok then fit a new bulb Geoff Link to comment Share on other sites More sharing options...
Shiremm Posted November 20, 2015 Share Posted November 20, 2015 What sort of outboard is it? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
stevefish Posted November 20, 2015 Author Share Posted November 20, 2015 2003 merc 3 cylinder 40hp Link to comment Share on other sites More sharing options...
Shiremm Posted November 20, 2015 Share Posted November 20, 2015 When was the last time you had the fuel pump overhauled? Is there any water in fuel filter? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
stevefish Posted November 21, 2015 Author Share Posted November 21, 2015 It's done 50 hours since the last service, Don't think the fuel pump has ever been overhauled. The fuel filter is not clear so I'm unable to tell what's in it. When I ran it after the breakdown I had the boat planing and everything seemed OK before it went bad again I've run it at home and seemed OK Obviously not though. Link to comment Share on other sites More sharing options...
JimT Posted November 21, 2015 Share Posted November 21, 2015 often running engine with-out a load ie at home, it may seem to run fine.....still need to check out fuel pressure, filters, electrics,fuel quality Jim... Link to comment Share on other sites More sharing options...
zmk1962 Posted November 26, 2015 Share Posted November 26, 2015 (edited) I read above that you have a breather hose fitted -- But have you checked the length of the breather - is it kinked or blocked anywhere?? Replace it if you are in doubt. I had an intermittent problem where my motor would not rev up from troll speed - when I applied throttle it would tend to die down and splutter like running our of fuel - when that happened I had to try and "goose" the throttle controls and eventually she would rev up... Long story short, after several good mechanics had already gone over and given a thumbs up to the motor, pump and filters I was about to accept this as a "feature" of the motor but then by chance while working on another bit I had my neck in close to where the hoses connected with the tank and notices that the breather was kinked. Changed the breather hose and the problem has not reappeared since. So my conclusion was if everything was flat and level - vapour would get thru the kink and the tank would breathe - hence most of the time everything was fine, but if some fuel had pushed up past the kink (like when you troll through swell) this trapped fuel would restrict the tank breathing and hence added restriction on sucking fuel when trying to rev up. You also mentioned that when you fill up "it appeared full with fuel coming up the clear filler hose" - was there fuel coming out of your breather?? If not, then again this is pointing to a breather problem. Edited November 26, 2015 by zmk1962 Link to comment Share on other sites More sharing options...
stevefish Posted November 26, 2015 Author Share Posted November 26, 2015 Thanks for all the input, I am now pretty confident I have bad batch of fuel. The same fuel is causing me drama in my 4 stroke brush cutter and my mower seems a bit wobbly as well. Now, what to do with 40 litres bad fuel? Link to comment Share on other sites More sharing options...
stevefish Posted December 30, 2015 Author Share Posted December 30, 2015 Update, After a bit of mucking around with breathers, replacing the primer bulb plus having the same experience again, I have the culprit. The tube fell off the fuel pick up fitting??? Ahh, boats eh Link to comment Share on other sites More sharing options...
antonywardle Posted December 30, 2015 Share Posted December 30, 2015 (edited) nice catch and thanks for keeping us updated so every time you used about 10 litres, the pickup wasn't long enough to drink. I guess in rough sea you'd have had a similar issue Edited December 30, 2015 by antonywardle Link to comment Share on other sites More sharing options...
stevefish Posted December 31, 2015 Author Share Posted December 31, 2015 Yeah, if I knew I could have bogged it in the arse and got home. Lucky enough I got home on the electric both times Link to comment Share on other sites More sharing options...
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