Super Jet Superjet wont go past 1/4 throttle with load

[kawa js550]

Went to try out my superjet for the first time today and soon as I started it in the water it idled good and I couldn't get it past 1/4 throttle. I tried many times to get it past and it doesn't even hesitate or try, it just dies. Ive been researching to try and find the problem but havent found much. I will toss new plugs in it tomorrow and see if that makes a difference. It doesnt have a exhaust leak so im thinking its a fuel/carb issue. It was set up for dual cooling at one point so im thinking the jets might of been changed for a pipe or something. It revs fine and runs great out of water but as soon as there is a load on it, it wont go past 1/4 throttle. If anyone can think of anything else that could be causing this, it would be a great help. Thanks

 

[Mike W]

I would inspect the inside of the carbs first. Check the jetting as well as the small fuel filters on the fuel pump side of the carbs. Also check and make sure there are no obstructions in the fuel lines, filter and fuel selector. I had a couple fuel selectors clog so I rule that out before anything.