Problems Starting

I have a 1991 Ski Nautique with a 351 Ford carborated. The other day I took it out, was idling and it stalled, after that I could not get it to start again. The engine cranks but won't fire, so it's either fuel or spark right, seems pretty obvious.
I checked a couple of the plugs and they look fine, they're practically new, and are sparking although its not the best spark but that's prob b/c its not grounded very well (just laid it on the block). So that leaves fuel, except that there is gas being pumped into the carb, I can smell gas on the plugs, I even poured a little gas right into the carb, and nothing.
It will crank all day but never fire. Any suggestions anyone?

I had to replace the spark plug wires when I was getting weak spark and that took care of my problem.

Check the resistance of the plug wires. (you shouldn't have much. Mine were measuring around 8ohms when I had to replace them.

Thanks but distributer, wires, and plugs are all less than a year old and seem fine, but I should check them anyway. Any other ideas

Do you have a safety cable switch? I have one on my Malibu. I can't think of the name right now. It'll be the driver. Fuse? Rotor? You should be able to take the spark arrester off to see if your getting fuel.

I had the same problem with my previous boat. Turned out that the float was sticking in the carb. Take a rubber mallet and whack the float side of the carb and try. If that works, you need to have the carb removed and rebuilt, should cost about or less than $300. Almost worth buying a new carb for $450.

Jeff makes a good point.... Also if hte boat has not ran very much lately... The choke could be sticking and flooding it out....

Could be a condenser too or just it's connection.

a carb rebuild for $300?? damn, i'm in the wrong business...

Had a similar problem and took a while to nail it down. The gaskets between the carb, spacer and intake were old and wouldn't seal. Couldn't create enough vacuum to pull fuel/air into the engine. An easy check with a spray bottle (water and a little soap): have someone turn it over and spray around the carb spacer. If you see bubbles or the water disappears, you have a carb gasket issue.

Check the choke. That carb will have an electric choke on it, and if it isnt set properly or is not releasing properly, lol

you can set them by just loosing off a screw.

if that doesnt work, just because parts are new does not mean they cant fail. check the distrib, plugs, wires.

Another check, mechanical fuel pump on that thing, they should actually temporarily stop flowing fuel while bowls are full. if the bowls are over filling you can get extra fuel through the carb, with a possibility of flooding out. but since you can start the thing now, it could be a combination of all of these.

Points??

if nothing else its good to change every now and then

My buddie's 93 supra (with a 351) wouldn't start and that was it, his father in law who bought the boat originally said they would go bad every few years. its about a 12 dollar fix...

if the boat has ever been left in the on position w/o running for any extended period of time even a minute or so they can burn up, did you replace the whole distributor or just the cap??

A long shot, but I had that problem in my 84 Stars and Stripes. Make sure the rotor is turning. I had broken teeth on the gear at the bottom of the distributor shaft. It was caused by an engine rebuild without putting a new distributor on, which had the old gear being turned by the new one on the motor. They didn't align perfectly and that tore up my distributor.

Thanks for all the tips guys but ended up being an ignition coil. Had a mechanic friend look at it, he replaced that, and I'm back running.