Engine Tuning Help!!

Hey Guys....I am hoping someone can help me out. I started my build 9 months ago and the ski still isn't in the water. I had a local engine builder build me a motor and after 5 attempts to dial the motor in and the ski is still running like crap. I paid very good money to have this done and have gotten no where. i am hoping you guys can help me out with how far out these carbs are.

It's a 760 running an aftermarket ADA girdled head. I will get the piston and dome size. It has mild case and cylinder porting. Im running Dual OEM 44's, a TBM flywheel, MSD Enhancer and Modified B Pipe.

The carbs are setup as follows

Main Jets - 130
Low Jets - 120
115 gram spring

The ski ran pretty well on land however when we put it in the water it sounded like the ski was almost loading up (bogging). As you would crack the throttle it was loading bad.

He said it was the spring and we needed 95's so I had to order those and get him back here for a 5th time. We put them in and the ski ran even worse! It barely ran on land and we didn't even put it in the water. As soon as the he would hit the throttle it bogged even worse and sounded like we were flooding it with fuel. He is at a loss and said he doesn't know where to go...gee thanks!! He supposedly rebuilt the carbs and they were "clean".

I am at a loss and just want to ride. Any input on the hi's, lows, springs and screw settings would be very much appreciated. Thanks!!
 

munki63

Epoxy is my duct tape
Location
Canada
First are you carbs new or did you buy them used? If you bought them used rebuilding them is never a bad thing to do if they need it, also take your carbs apart and in every hole spray carb cleaner, make sure all you're carbs arnt plugged anywhere. check your compression
2nd Im a Yamaha guy so im not sure how close your jetting will be to mine, im running a ported 701 with dual 44, same pop off you have my main jet is 100 and my pilot jet is 120 but its too big and im having starting issues.
 
I am new to the sport and was building a boat that i could grow into.

update piston and dome size....The ski is a 760 running an aftermarket ADA girdled head. I will get the 84mm pistons and domes to give it 185psi. It has mild case and cylinder porting. Im running Dual OEM 44's, a TBM flywheel, MSD Enhancer and Modified B Pipe.

The carbs are setup as follows

Main Jets - 130
Low Jets - 120
115 gram spring
 
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