In 2006 I installed a brand new "out of the box" 9.9 Mercury kicker motor on my Sea Nymph GLS 195. My main power is a 2000 model Johnson
115 - 2 stoke ( I know....). The GLS has a 40 gallon tank and a 5/8 inch fuel line to the Johnson 115. I used a T fitting and shut-off valve to connect the 9.9 to the existing boat fuel line system.
THE PROBLEM:
The 9.9 starts and runs for about 10-20 minutes and then slowly dies as the fuel in the line empties. If I can get to it real quick and pump the in-line ball pump, the motor takes off again. If I don't get to it, the motor dies.
I have tried several things.... Any ideas out there?
Thanks, Wild bill

take the plastic hose clamps off of your fittings and replace them w/ steel.

take a look at this thread from 2-3 weeks ago, T Mac talks about a Yamaha kicker fuel pump, that also fits Mercury's. My guess is that the OEM pump just isn't strong enough to consistently draw from the in-floor tank.
http://www.walleyecentral.com/forums/showthread.php?t=145787&highlight=yamaha+fuel+pump

HRG

Thanks to both of you for the info. I can see how the plastic wire tie clamps could allow pressure to leak.
Also, I wondered about the fuel pump. I assume it is a mechanical pump? Anyway, is there an electric in-line pump that could be installed?
I will check with my local boat guys and see what they have.
later, Wild Bill