loss of power when running full out

Post by **llm54** » Tue Aug 05, 2008 9:42 pm

I have a 93 Princecraft with 70 Johnson and built in fuel tank.
My problem is when I run full or almost full out for five minutes the boat looses power then surges.
My gas bulb is completelyflat so I am thinking the motor is starving for gas. I changed the bulb but same thing happens.
Any suggestions? thanks

Post by **SixStringHack** » Wed Aug 06, 2008 11:16 am

Check your anti-siphon valve for a partial blockage or the pickup in your tank (if it has a screen). Follow the fuel line from the bulb to the tank to check for kinks or weak spots. I had a cricket in my anti-siphon valve this spring and there was only enough fuel getting through to let me run at 3500 rpm without starving the motor. I replaced the anti-siphon valve with a straight-through connector and my problem went away.

I confirmed the problem was not in the motor itself by connecting up an external tank to see if the problem went away. It did, so I knew the problem was in the boat...

Good luck

Post by **lnguyen0929** » Sat Aug 09, 2008 11:38 am

It happened to me with my 25HP Johnson outboard...I took out the gas tank,line and clean out the filter.After that the gas can supply full out when you accelarate all the way.Ensure you use the air to blow everything out...I dont know some how i got a few dead bugs in the gas filter....How could they get in there first place???