Primer Ball Question

[jimmer]

Hi Guys

Hoping someone out there can answer this question. I have a 25 hp Yamaha, put a new gas line on it at the end of last year, I run it wide open for a bit, then it dies. I pump the primer ball at it throttles up again but the ball is collapsed like there is a vacuum inside. Anyone have any ideas what is causing this? Is it possible it's the tank?

Thanks!

[Sinker]

I assume its on the right way?

 

S.

[LeXXington]

vent closed

[DanD]

Fuel tank vent clogged, not allowing air in tank? Try running motor with gas cap removed. The fuel pick-up line inside the tank, clogged or collapsed; not allowing fuel to pass?

The motor's fuel pump must be working because it's sucking the primer bulb down.

 

Dan.

[mike rousseau]

I assume its on the right way?

 

S.

Sounds funny but mine was installed backwards from the dealer

 

Idled great then stalled when opened up and ball collapsed

 

There's an arrow on the ball and it should point at the motor

[AKRISONER]

whenever Ive forgotten to open the breather valve I notice that my entire tank suctions...but you may be using a steel tank. It definitely sounds like the breather valve is clogged. Trust me I scared the crap out of myself one time after making a really long run in the evening I was one my drive home as it was getting dark and my engine stopped...stupid me.

[jimmer]

Thanks for the replies. I will add some more info: The arrow is pointing the right way, it's a plastic tank and the pick up is made of hard plastic, I took the cap off and actually took it apart to make sure the vent wasn't clogged (it was clear).

Is it possible that the connection on the tank is damaged internally?

[DanD]

Take the fuel line off from the inlet side of the primer bulb and try blowing air back into the tank. It shouldn't take much effort to blow a steady stream of air through the line and get bubbles in the tank.

 

Dan.

[jimmer]

Thanks Dan, I will check that out.

[Fisherman]

Well if the pick up was clogged or the primer clogged then it wouldn't allow fuel to be picked up in the first place.

[BillM]

Well if the pick up was clogged or the primer clogged then it wouldn't allow fuel to be picked up in the first place.

 

It might allow enough for idle, but as soon as he goes WOT, not enough fuel.

[DRIFTER_016]

I had a brand new ball that did that.

Was an issue with the ball.

Bought a different brand and all was good.

[chris.brock]

 

New fuel line eh, my guess is it's not the right one or a crappy one and the valve on the connector to the tank isn't opening all the way.

[Rattletrap2]

The fuel tank on my 20 HP Merc did that many years ago. Turned out the screen on the bottom of the pick-up tube had slid up on the tube for some reason. At low idle or low speed, enough fuel would get by to keep the engine running. Once you cranked the throttle, the engine would run out of fuel and die. Once the motor sat for a minute, enough fuel would get by to start it up again. I removed the tube and attache the screen more securely with a clamp or tyrap. I have no idea how or why it did that.

[jimmer]

Lots of things to check and consider. I have replaced a couple of primer balls and connectors over the last few years and thought I had it figured out. Just had put two new connectors on this spring due to the small gaskets breaking. Not sure if there is a better quality primer ball available. I had bought one last year and it didn't work from day one, so I replaced it with the one I have on there now. I'm leaning towards the problem being between the primer ball and the bottom of the gas tank. I'm going to pull out the pick up tube, maybe the screen is gummed up from ethanol.

[Sinker]

Just disconnect the gas line from the tank, remove the end and put it directly into the tank and see if that works. Just by pass the pick up in the tank.

 

EDIT: if it was be I'd just go buy a brand new gas line and go from there. Get one that's alcohol resistant.

 

 

S.

Edited May 11, 2017 by Sinker

[jimmer]

I've bought new gas lines twice already in the last year Sinker. However, it could be the after market parts just suck. Even when I order parts from the Marina, they give after market parts. Those connectors that are bought off the shelf just seem like they never fit right. I will try that by-pass; not sure why I didn't think of that. LOL

[jimmer]

Just thought I would update on this issue. I pulled the tank apart and the pick up looked fine. I noticed that the male connection on the tank was out of round a little, so I re-shaped best I could. I took it for a run with the tank on the seat beside me and it ran fine, put the tank and the floor and there was an issue. I pumped the ball in a vertical position and parked the boat. Went out on opening day and didn't have a problem with it. (go figure) I also bought a new after market tank and connector just in case.