Primer Bulb issues, and an idea...

[JasonJ]

(69 Merc 1250, but don't move, its a generic question and idea). When I pump my primer bulb, I don't always get the rock-hard action like I should. With three different bulbs it does this, it acts like it isn't pumping, and the motor can take longer to start because of it. I have checked, there is no stuck float needle issues or any of that. One time it will act mushy, another time it will act properly.<br /><br />My idea, and it is just an idea, is I have a 12v fuel pump (for EFI, so there is a good amount of pressure). Has anyone ever wired a pump in to act as an electrical primer, just bump the switch for a couple seconds and start, or is it just too outlandish an idea? I would have to check that fuel will flow through it when the pump is not actually running, but I am growing weary of the iffy bulb action (I would still leave the bulb as passive back-up). It is so intermittent that tracking it down is almost impossible. I almost ran my battery down last year out on the water because of this problem, and it was with a new bulb. Thoughts?

 

[backdraft]

Re: Primer Bulb issues, and an idea...

Yes, I use an electric pump to prime my 125 all the time. Easier to use on those frigid mornings and 3 times faster. Just lookout for leaks. Use a switch that has to have you push it to work and when you release it , it shuts off. nevjb

 

[Solittle]

Re: Primer Bulb issues, and an idea...

I had them on my twin 110s but went back to bulbs when one of the electric motors went south. Just more stuff to have to fix at some point.

 

[ED21]

Re: Primer Bulb issues, and an idea...

Is it possible you are having a fuel pickup problem? Last year I had a metal pickup tube in the tank split about half way down. When the tank was full no problem. When it got about half way down it would run poorly & the bulb wouldn't get hard.

 

[rickdb1boat]

Re: Primer Bulb issues, and an idea...

Jason<br /><br />Any chance of intermittant air leaks at the fuel fittings or lines causing the odd bulb problems?

 

[dajohnson53]

Re: Primer Bulb issues, and an idea...

Originally posted by nevjb:<br /> Yes, I use an electric pump to prime my 125 all the time. Easier to use on those frigid mornings and 3 times faster. Just lookout for leaks. Use a switch that has to have you push it to work and when you release it , it shuts off. nevjb

A "momentary" switch! I was reading this thinking - that type of switch has a name. Last time I was shopping for one (a rubber, weather proof pushbutton for my horn), I used your exact words to describe it to the guy at the parts counter and he said "oh, a momentary switch". I'll go back into my hole, now. By the way, I try to find these sort of things (switches, fuse or ground blocks, etc.) at a truck/trailer supply house. Same stuff as the boat shop, but 1/5 the cost.

 

[quantumleap]

Re: Primer Bulb issues, and an idea...

I think Ed may be on the right track. Try to check it with the tank filled to varying degrees. If it works fine full, then it's a leak in the pickup line.

 

[JasonJ]

Re: Primer Bulb issues, and an idea...

Fuel tank is brand new, lines and bulb is new, and it does it on a portable 6 gallon Merc can that also has new bulb and lines as well (It also did it on the old steel tank). Its bizarre, but manageable. I think I may try the electric pump, if it doesn't work the way I would like it to, I can always just yank it out.

 

[Hooty]

Re: Primer Bulb issues, and an idea...

I removed the pulse fuel pump from my 2.4L Mercury and use a Holley red fuel pump. I wired it through a covered aircraft type on-off toggle switch and through the kill switch. Raise the cover, flip the switch "on" and crank it up. Beats the bulb.<br /><br />c/6<br />Hooty

 

[JasonJ]

Re: Primer Bulb issues, and an idea...

I have considered wiring it through my choke button. I never need the choke to start it, it makes it harder to start if I use it. I'll have to think about that one....

 

[mellowyellow]

Re: Primer Bulb issues, and an idea...

JJ, have u looked at your check valves yet?<br />bulb/line should be perpindicular, not horiz.<br />as u all know, right? <br />once had air leak in quick-connect cause same<br />symptom, so maybe as Rick suggests air infiltration<br />somewhere along the line?<br />good luck,<br />M.Y.

 

[Dhadley]

Re: Primer Bulb issues, and an idea...

Every V8 E/J ever sold came with a primer pump and momentary switch. There was no primer bulb on a V8. The pump had a by-pass circuit T'd right in so the fuel didnt pass thru the pump (restriction) if the pump wasnt running.

 

[Bass Runner]

Re: Primer Bulb issues, and an idea...

Jason you and I must be on the same wave link, I have a electric pump in line and guess what i use for a switch? I use a choke switch out of a early 70's control, works like a champ unless you have a float stick then the fish don't like you much.

 

[JasonJ]

Re: Primer Bulb issues, and an idea...

Yesterday out of boredom I went down to dink with it and of course the bulb did the apropriate rock-hard thing. That fuel pump I had is not going to work so if I want to do this I'll have to buy one (not the end of the world). I have played with different angles on the bulb while pumping with varying degrees of success. Its not a big deal, it has always started this year, so we'll see.