1979 Mercury 9.8 stalls at high speed

[Stoehrdp]

I have a 1979 Mercury 9.8 I bought off ebay. I bought a new tank and hose for it from boaters world.<br /><br />When I open the throttle up, it dies after a few minutes. Seems to run a lot longer when in trolling mode.I'm pretty sure the problem is in the fuel system as squeezing the bulb helps sometimes and makes it stall other.<br /><br />Are there any simple things I can do before bringing it in for repair?<br /><br />Thanks<br />Dave

 

[claytonr]

Re: 1979 Mercury 9.8 stalls at high speed

I don't know whether or not you have a choke or a primer knob/button. In either case make sure that it isn't engaged. I bought a brand new merc that has a primer knob and was having the exact same problem. It turned out that I kept forgetting to push it back in (disengage it)after it started and warmed up. When I would try to gain speed, it would bog down and sometimes die.<br /><br />Good luck.

 

[Fouled Plug]

Re: 1979 Mercury 9.8 stalls at high speed

Sounds like it could be the fuel pump diaphragm. Pick up a manual for the motor and get familiar with it.

 

[Astro18]

Re: 1979 Mercury 9.8 stalls at high speed

I agree...check the fuel pump diaphragm.