Bulb went soft and engine died

[cnccustom]

Today after being out all day with no problems my 75 merc 850 died in the no wake zone it was obviously starving for fuel, checked the bulb and it was soft, pumped it up and started right up with no more problem through out the rest of the day......I just put a new bulb on it...tempo brand and have heard since then that the tempo brand is not that good......could this be a bulb problem or low fuel pump pressure at low rpm....

we were in the no wake zone for about 45 min. to an hr. when it happened.......most of the day we were at 3/4 to full throttle with no problems.........Thanks

 

[Plainsman]

Re: Bulb went soft and engine died

May be time to rebuild the fuel pump, but I'd try another bulb first.

 

[studlymandingo]

Re: Bulb went soft and engine died

I'm gonna go with the fuel pump theory myself. Usually the issue with bulbs is the check valve doesn't seat properly and they won't pump up to begin with. I think you are looking at a fuel pump or possibly an air leak somewhere in the fuel system (line or fitting).

 

[Vlad D Impeller]

Re: Bulb went soft and engine died

If your rig has a vent hose, my theory is inadequate fuel tank venting caused by occasional blockages in the vent hose due fuel sloshing around in the tank.
See if there is a dip in the vent hose where fuel could accumulate.

 

[cnccustom]

Re: Bulb went soft and engine died

Thanks guys....no problem with the vent hose vlad...I will check out the fuel pump.....are they hard to rebuild...

 

[sport15]

Re: Bulb went soft and engine died

The engine worked great, you changed the bulb, bulb got soft and engine died. I suspect the bulb, in the fuel line with a small air leak. (Ms Scarlet and Col. Mustard were getting hammered in the kitchen!)

Something happened to the system when you did the bulb. Soft bulbs mean air is getting in or no fuel is being picked up (loose tank fitting). I had a similar problem about two weeks ago with an unexpected soft bulb and after changing tanks it went away, turns out the tank fitting didn't seat.

The engine fuel pump is easy to do, you can get a kit right from mercpartsexpress.com and don't forget to change the pump to crankcase hose if your engine has it, an air leak there will weaken the pump..

 

[cnccustom]

Re: Bulb went soft and engine died

no I changed the bulb about 3 weeks ago for another problem ...the bulb fixed that.....

Thanks for the link to mercparts