primer bulb issue

[John c 79]

314-8, I installed a primer bulb last fall to correct a long crank time issue, which it did. Right away I noticed after a few minutes of running the bulb would be drawn in almost to the point of being flat, the engine would continue to run though. Now after having cut with it a few times it will starve to point of dying but only when cutting across a slope with the PTO side downhill, fine up or down hill or PTO side up. Acts the same with or without the tank cap on tight. 

 

It's just dawned on me this morning as I sit here typing this out, the PTO side down issue may be simply there's enough angle there to prevent fuel from fuel from continuing up that small upturn in the hose path just ahead of the bulb, I've got some more troubleshooting to do and will report back, 

 

In the meantime.......

 

Any of you guys running a primer bulb set up have any issue with the bulb being sucked in 

 

[gwest_ca-(File Mod) 11,048]

Sounds like the screen on the tank valve is plugged up.

Try to drain the tank into a gas container to see if gravity will drain the tank. If it will not empty the tank and screen need to be cleaned.

[SylvanLakeWH 25,602]

 

I've used one for years and never had issues... 

 

I did change all lines, leaking fuel shut off valve and grommet on tank when i did it...

[wallfish 17,014]

The fuel pump pulls fuel through the bulb and fuel lines so up turn/down turn of the line doesn't matter much if the pump is pumping. Weak pump could cause an issue.

I don't remember where the petcock is on the gas tank or how steep the hill is, could it be tilting that way long enough and low fuel in the tank is the problem?

[Kenneth R Cluley 527]

Run a primer on my round hood, never had issue with it. Seems to me that it must be upstream of bulb to cause it to collapse. Agree with checking the fuel flow from tank up to bulb. Pump must be working to create suction to collapse bulb! Suspect the screen since it gets worse the longer it runs. 

[Ed Kennell 38,230]

If the fuel pump is sucking the primer bulb flat, you have a strong fuel pump.        There has to be a blockage between the primer bulb and fuel tank.      clogged screen in the petcock,  clogged vent in the fuel tank cap,  something in the tank that is floating and covering the screen, a kinked or pinched fuel line,   could also be the inlet check valve on the primer bulb is sticking closed.

Edited May 1, 2023 by Ed Kennell

[Handy Don 12,237]

4 hours ago, gwest_ca said:

Sounds like the screen on the tank valve is plugged up.

Try to drain the tank into a gas container to see if gravity will drain the tank. If it will not empty the tank and screen need to be cleaned.

Or the vent in the gas tank cap is clogged.

Unlikely but theoretically possible: the one-way valve at the tank end of the squeeze bulb is jamming closed?

[c-series don 8,724]

Maybe blow a little compressed air backwards in the fuel line to clean the screen in the tank valve? Just a thought.

[John c 79]

I had replaced the fuel tap and gromment a few years ago, and I don't recall the new one having a screen on it, so I didn't replace it last fall but I did replace all the lines and filter.

 

I wonder maybe if I don't have the tank tap all the way open.

 

It does the same thing with the cap on or off, so the cap vent is fine. 

 

And it always starts right back up.

 

I'll try and look at it some more this afternoon.

[Ed Kennell 38,230]

6 minutes ago, John c said:

I wonder maybe if I don't have the tank tap all the way open.

I would pull the fuel line off the inlet to the primer bulb and see if you have a full free flow of fuel from the tank.    If not, find the restriction.

[clueless 3,005]

Put the primer bulb before the inline fuel filter. 

[Bill D 1,926]

On 5/1/2023 at 9:11 AM, John c said:

I had replaced the fuel tap and gromment a few years ago, and I don't recall the new one having a screen on it, so I didn't replace it last fall but I did replace all the lines and filter.

 

I wonder maybe if I don't have the tank tap all the way open.

 

It does the same thing with the cap on or off, so the cap vent is fine. 

 

And it always starts right back up.

 

I'll try and look at it some more this afternoon.

Personally I wouldn't use a fuel tank valve without a screen.  Too much risk of debris in the tank clogging the valve.

[John c 79]

Bill D says.............Personally I wouldn't use a fuel tank valve without a screen.  Too much risk of debris in the tank clogging the valve.

 

And after this incident neither will I, what looked like a stem from a small leaf was sitting right in the opening of the valve. I never really gave it much thought before now, just figured any debris would pass through the valve and the filter would catch it.  I guess that was enough to collapse the bulb but not starve the engine until the low flow couldn't make the slight uphill flow in the line and sustain the engine when tilted right side down. 

 

Rotary #8675 is a valve that has the screen on it. About $10 on A-Z should be here in a few days

 

 

Thanks your comments and help guys....

[Ed Kennell 38,230]

On 5/1/2023 at 9:20 AM, Ed Kennell said:

I would pull the fuel line off  find the restriction.

A leaf stem....who woulda thunk it.