Cylinder Drain System 1993 Force 90HP

[alounsbury]

The force engine has a small (approx 1/8") hose that connects from the cylinder drain cover to the intake manifold for each cylinder.<br /><br />If this was plugged or the check value failed - does anyone understand the effect it would have? Could this account for an engine with the following behavior. <br /><br />a) launch boat - no problems with initial 10/15 minutes of operation<br />b) after that - engine will stall if throttle is advanced slowly from idle to full speed at around 2000/3000 RPM. Engine will not stall if punched to WOT.<br /><br />Looking for new ideas since have almost eliminated everything else - carbs, timing, synchronization, etc.

 

[ewaltb]

Re: Cylinder Drain System 1993 Force 90HP

Have you checked the fuel pump? Sometimes a whole in the diaphram will cause the same problem. I have a '93 120 Force. It did for me, but I had a quarter size hole.

 

[alounsbury]

Re: Cylinder Drain System 1993 Force 90HP

Thanks for the idea. I already took the fuel pump apart apart more for curiousity and to see if the screens were dirty - but alas all was well.<br /><br />I suspect if the diaphram had a hole in it, it would be consistent in behaviour whether the engine was hot or cold. This problem is seriously illuding me since it runs literally perfect when first launched/started that day. Then after that - the stalling problem on slow accerleration only appears.<br /><br />I'm at a loss and this problem is certainly not obvious. So it's now into my fav boat mechanic. Will advise everyone once he has an answer.