1993 70 HP Force bogging down

[stebek]

This 70hp Force had run fine for my first 10-15 hrs of running time under my ownership. Then it started to cut out at high speed.Would run fine when not running at high speed. The problem has slowly worsened to where it will bog down at a little over half speed.Seems to be starving for fuel. Will then start right up.The boat,a 1993 17 foot Maxum bowrider had been sitting for 4 years.Has very low hours and was professionally maintained and winterized. After my purchase I replaced old fuel,plugs,and filter. One other thing is when problem first started primer bulb collapsed but that doesn't seem to be happening anymore

 

[12Footer]

Re: 1993 70 HP Force bogging down

It is a fuel delivery problem,considering the bulb collapsed. A collapsing bulb means the tank wasn't giving fuel to the engine.<br />This could be because the vent was closed or plugged, the pickup tube was plugged, or the anti-siphon check ball was sticking in the pickup tube.<br />The next time it acts-up, have someone squeeze the primer, and see if performance picks-up. If it does, the prblem could be air getting into the fuel line, or fuel pump not drawing enough fuel from the tank.<br />This (fuel pump) sounds like a logical point to start,as it probaby damaged an allready dried-out diaphram (sitting dry 2 years), from drawing a too-thick milkshake thru too small a straw.

 

[ChalkBoy]

Re: 1993 70 HP Force bogging down

This is not uncommon. I have an '87 85 hp Force, and I had the SAME problem last week. I thought I blew my engine... However, after examining the fuel line, I noticed that the bulb collapsed. THIS HAPPENED BECAUSE I DIDN'T VENTILATE THE GAS TANK. As soon as I released the suction, everything was fine.