95 Johnson Fast Strike 150 HP issues

mattenloe

Recruit
Joined
Oct 6, 2008
Messages
2
I recently purchased a 95 Johnson Fast Strike 150 HP motor on the back of a Stratos Bass boat. The motor is mounted on a jack plate and the throttle is controlled by a hot foot. It starts just fine and idles perfectly and also cruises at low speeds just fine. The trouble comes at the high end when I try to take it over 40 MPH it will sputter a bit then completely die. Here is the kicker it will work just fine at high end if I pump up the ball every single time I start the motor, that includes after I stop and fish for a few hours. I have to pump the ball until it is very hard and tight, but it does not seem to hold pressure. I have replaced the ball and the previous owner does not have a clue what is going on since this didnt happen to him at all. He did replace the fuel filter right before I purchased the boat. Any suggestions would be great!

THANK YOU!!!
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: 95 Johnson Fast Strike 150 HP issues

Look for air leaks on the fuel supply side from the tank to the carburetors. Watch closely when you pump the primer bulb: if any gas flows out, air can get in.

The primer bulb should not stay hard once fuel begins to flow through it, nor should it collapse.

At the point that the fuel pump begins to control the flow, you could think of the primer bulb as just part of the fuel hose.

Don't overdo it on squeezing the bulb, too much pressure can rupture the fuel pump membrane.
 

mattenloe

Recruit
Joined
Oct 6, 2008
Messages
2
Re: 95 Johnson Fast Strike 150 HP issues

How would I be able to tell if gas is flowing back out? Thanks for your help.
 
Top