Year long Craigslist Project Ski SO CLOSE to working!

robcarync

Petty Officer 3rd Class
Joined
Aug 19, 2010
Messages
82
Alright guys, I have posted about this ski a couple times and I figure random stuff out every so often and I think I may have it down to the last problem:

94 Yamaha Waverunner III 700 cc engine

After rebuilding the carb, replacing fuel filters, fuel lines, converting ski to pre mix and replacing all the gaskets on the intake side of the engine...the ski RUNS GREAT...you can hear the throttle response is full and there is no missing like there used to be and the exhaust has quit smoking so much.

the problem is it runs great on the trailer under the house, but every time I drop it in at the boat ramp is won't start up (starter turns, its a new battery, but it just won't get started) .

Now ... the fuel filter I put in is clear so I can see the fuel flowing (or not flowing) through the lines.

Firstly, the fuel filter is never completely filled with fuel (usually stays about halfway filled, the filter sits vertically so the fuel fills about halfway up the cavity inside the filter)....you can see air inside the filter. I would think that the suction from the engine would get all the air out and that the filter would be completely filled with fuel....does this make sense? Even after running the engine for a while on the hose, the filter never becomes completely full with fuel. Is this normal?

Secondly, when it wouldnt start in the water, I opened the hood and watched the fuel filter and noticed that there seemed to be no fuel in the filter. WHen pressing the start button, it did not seem to be pulling any fuel through the filter.

Once I got it on the trailer and got it home, I had to put a few drops of pre mix into the carb to prime it and get it started....once I got it started....it ran great.

So it seems that somehow between my house and trailering it to the ramp and backing it into the water, fuel is leaking out and leaving the fuel lines dry. I have put hose clamps on every fuel line connection so it doesn't seem that its a lose hose connection. I had rebuilt the carburetuer so I would hope that the gaskets aren't leaking out somewhere....but I will check that this weekend when I head back to the beach.

Is there any other reason anyone can think of or other sources of a leak that would cause the fuel lines to be dry after it sits a while/gets towed around on the trailer?

ALso, does anyone know the proper fuel line size? I had 1/4 " on originally but they were really loose on the carb fittings so I dropped it down to 3/16"....could a smaller fuel line restrict the fuel flow enough to cause problems?
 
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