Keep in mind that I have been messing around with my 2003 Suzuki DF70 for about 3 weeks to get it to run right. I have posted here before about it so let me get you caught up to speed. 2003 Suzuki DF 70 that I recently serviced (did all the work myself) including all filters (oil, high/low fuel), new battery cable, new control cables, spark plugs (including 1 extra on # 3 cylider that didn't seem to be firing), change oil in lower unit, water pump, Prop tuned up at Bobby Soles props in West Palm Beach. Now following the advice I got here on iboats.com I have followed all recommendations including checking for spark, fresh and I mean fresh fuel in NEW gas tank, got service manual on the way from Brownspointmarine (not here yet), made sure no kinks in any lines (fuel or electrical). So now that we have that let me tell you what happened yesterday. Went to start the boat, squeezed bulb until firm, turned key and engine starter fired up great but engine didn't start, advanced idle throttle and it fired up on second try (once warm no problems restarting), cruised down our canal at 1200 RPM (occasional power would drop by 50-100 RPM), get out in the ICW and start cruising at about 2000 RPM (still occasional brief drops in RPM), cruise around for about 1 hour then on way home open up throttle to 4000-4500 RPM, sounds good, no drop of power, then all of a sudden power drops to 3000 RPM and starts to run rough, NO WARNING lights. Get to sandbar and shut down. Look for any obvious loose wires (none), fire the engine back up and limp for about 20 minutes, engine still running rough, pull back to idle and engine quits completely, fires right back up and is running smoother, open the throttle and runs great then 5 minutes later powers back to 3000 RPM (cant get it to go higher), limp back home to dock. Take the hatch off and put the engine on the muffs, won't fire up with even the slightest tilt on the engine, get it level and fires right up, there is a strange hissing sound from the side of the engine with the spark plugs that is heard when the engine is running a little rough on the muffs and then goes away and engine runs smooth again. The only other thing to add is the slight smell of gas. Now I am thinking one of 2 options, #1 still having an intermittent dropping of the spark on # 3 Cyclinder or #2 it is the Fuel Pump/Diaphragm. Now you only have one guess, after reading my lengthy post what says you? What page should I turn to when my service manual gets here?
