Tuning update / New issue
 

I was finally able to take the boat out yesterday on lake michigan. I had adjusted the cold start inrichment and am now seeing AFR's around 11.8 at idle. way better than the 9.8 it was. I was running slowly at first between 2 & 3000RPM. AFR's between 12.8 & 13.2. I headed for the inner harbor as it was rough enough for my laptop to be jumping off of the passenger seat, not to mention holding the AFR meter between my legs. Anyway the boat was running fine until I got just about to the south gap to head in the harbor. The waves were building a bit and there is more of a chop due to the water coming back off of the break wall. At about 40MPH the boat left the lake and returned pretty hard ( I think I'm a bit shorter now) The boat also disagreed with this. Fell off plane motor sputters and dies. I try to start it again fuel pump runs motor fires right up then sputters and dies. What do you think? Possible damaged fuel pump? When it fires it sounds fine just doesnt run long. It acts just like its running out of gas, tanks are 3/4 full (75 gal). I looked at the obvious in the lake but was towed in by the Milwaukee police boat (fun). Any thought ideas or direction would be great.

Im no pro, but I would check the fuel pressure if you havent already. Its a start. Rob

What kind of ignition are you running? I had a MSD coil go on me a couple years ago during a poker run. It was really choppy on the water - hitting lots of big waves. Hit one big one that felt like we were right out of the water - hit hard coming back down, the motor sputtered and died. Would start up again, but then sputter and die - just like it was running out of fuel. I had half a tank still. Spent the rest of the day going through everything with no luck. Checked for spark on the plugs and it was really weak and intermittent. Read through MSD's manual and it said to check the coil (MSD Blaster). Sure enough as soon as I put in a new coil the motor fired right up and ran great! MSD makes a high vibration version of their Blaster coil that is way tougher than the standard version.

I did check the fuel pressure, I did not mention this at first sorry. The pressure went up about 5lbs. at idle, well sort of idling. I decided to look at the H2O sep fuel filer due to water not compressing like gas does. I poured the gas/water out of the filter into a glass tray. I seem to have water in the gas. The rough ride mixed it well enough to kill the motor.( I tried to go green but the boat just won't run on water:D) I replaced the filter and ran the fuel pump to purge and fill the filter. I then hooked it up back the the relay removed the plugs and coil wire turned the motor over. I then disconnected the fuel pump and crank the motor over again to dry out the cylinders. Installed the plugs and tried to start it. The motor cranked a bit before a bark or two. I let it sit a little while then tried again, a few more barks then a crap idle. I let it run for about 30 secs and it started to clean up and idle smooth. I do believe I got lucky here. Anyway thanks for the replies.

Does anybody think I should run the fuel pump for a while to get the water out and then change the filter again, or should I pump the fuel out of the boat through a water sep filter then back into it?