96 XP hydrolocking/flooding after filling gas tank

[tingraham]

Good morning all,
Wanted to see if anyone had some ideas of hydrolocking on my ski. Filled the tank yesterday and put it in the water, it stayed in the water all night at the dock and when I went to crank it this morning it was hydrolocked. It was a ton of fuel mainly in the mag cylinder. I did leave the fuel on and obviously I shouldn’t have. I also have a primer set up on the ski. Has anyone seen the primers leak fuel when sitting? I just replaced the needles and seats with mikuni Viton needles because it was flooding a bit before but not this bad, but this is the first time I have filled the tank in quite some time.

Thanks for any tips!

 

[mikidymac]

The primers can go bad and leak if there is fuel pressure in the tank.

But, did you check the carbs for leakdown after you installed the new needle and seats? The crap aftermarket diaphragms can cause the needles to leak.

 

[tingraham]

I didn’t do a leakdown test after assembly but I am using genuine mikuni diaphragms, they could possibly be older though. I’ve had so many sets of carbs apart in the past year, I can’t keep track of which have what new parts.

I have been leaving the gas cap loose and the fuel off and so far no issues (as expected).

 

[Matt Braley]

Your ON fuel line is the last place that you want your primer drawing from because they do love to fail and they allow air in and then the engine runs lean. If you only use RES when you run that low I'd put the primer there because it will have it's own separate channel. A safer choice is to put a large loop in the return line and pick the fuel up from the bottom.

Since you used the right carb parts you may have a clogged tank vent if the primer is not at fault. They are supposed to pop off around 3 psi.