Primer Bulb?

[Snivley]

Hey guys,
My boat has been running great (mechanically) the only quirk the engine has is when starting. It turns over fine, but is slow to initially get gas. Once it starts, it turns over every time I hit the key until parked for a bit. I am sure I could spray it with some starter fluid and it would turn right over. Probably would also benefit from a new inline fuel filter.

What I was wondering is has anyone added a primer bulb to theirs? All my previous boats were outboards and had primer bulbs. I am not sure if this is also something folks do on inboards or if there is a better solution. Just not keen on having a spray can of starter fluid rolling around the boat. Not really an issue as it is now, just takes a little longer at the ramp to get started if it has sat for a week or two than I like.

 

[Maclin]

I would spend any effort on finding out why the carb drains down so fast.

Number one issue is compliance with Coast Guard regs, those are not allowed in I/O setups if memory serves. Problem with primer bulb on an I/O engine is it adds too much rubber hose in the plumbing before the pump, that much hose can flatten down as the fuel pump builds vacuum thru it. And where do you put it so you can get at it easily, you will end up with a lot of hose with fuel in it laying around somewhere inside the boat under the engine house. On an outboard most of it is in the splashwell. And the I/O auto-style engine fuel pump can flatten the bulb. The primer bulb systems are for lower vacuum mechanical pump that needs priming. The I/O auto style pumps do not need priming.

Work on the carb bowl drain-down. Also you could try starting it at home on the muffs first if it has sat too long.

 

[Snivley]

Thanks Maclin. That all makes sense. Certainly don't want to do anything that would not be compliant for sure. I will look at the carb. I am in Texas and we have been over 100 degrees the past few months. Could temperatures have an impact on it?

 

[jerryjerry05]

Look at the anti-siphon valve first.
If the ball isn't seating it will allow the fuel to back feed to the tank.
Installing a primer bulb can be done.
The Force /Bayliner combo used to have a contraption called an L-Drive(Not good) It was essentially an I/O.
They installed a primer bulb because the fuel pump didn't have enough UMPH to draw fuel to the carbs on a cold start..
The Coastie's wouldn't care if you installed a bulb in the engine compartment.
But that's just another thing that could go wrong.
The anti-siphon valve? The fuel pump could be weak?

 

[Maclin]

The temp is a factor I am sure in the evaporation of fuel from a carb's fuel bowl, but still should be a slow rate, thinking 2 months it should still have some fuel in the bowl, enough to feed the accel pump circuit and even main jets. Depends on the carb. Some have components and structures like welch plugs that can leak fuel.

That L-drive is a 2 cycle engine mated to an I/O lower unit, so I can see why it would have the primer bulb setup.

 

[Maclin]

Jerry,

I think this is what I was remembering, just that the primer bulb plumbing adds a lot more hose inside the boat and can be a hazard if cut, that type of thing, adds to the possibility of exceeding what is stated in number (2) below...:



FEDERAL LAW
183.558 - Hoses and connections
(b) Each hose used -

(1) For a vent line or fill line must be:

(i) "USCG Type A1" or "USCG Type A2"; or
(ii) "USCG Type B1" or "USCG Type B2" if no more than five ounces of fuel is discharged in 2-1/2 minutes when:

(A) The hose is severed at the point where maximum drainage of fuel would occur,
(B) The boat is in its static floating position, and
(C) The fuel system is filled to the capacity marked on the tank label under Sec. 183.514(b)(3).
​

(2) From the fuel tank to the fuel inlet connection on the engine must be:

(i) "USCG Type A1"; or
(ii) "USCG Type B1" if no more than five ounces of fuel is discharged in 2-1/2 minutes when:

(A) The hose is severed at the point where maximum drainage of fuel would occur,
(B) The boat is in its static floating position, and
(C) The fuel system is filled to the capacity marked on the tank label under Sec. 183.514(b)(3).
​