1996 seadoo challenger 787 carb engine problems

[JRogers]

I bought this boat recently. The po said that he never ran it and it has been sitting for 2 years since he bought it. The last registration sticker was 2017. The motor was full of oil when I got it. I pumped out the oil ran it on some premix to clean everything out. Ran the premix directly into the carbs. Rebuilt the carbs twice. Pto comp. is about 126psi and mag is about 148 psi. I measured the original pop pressure at abouy 15 and 22. After the 2nd rebuild they are both at 30psi. It was a pretty crappy rebuild kit by Venom, but I changed a couple of parts to make sure that those parts were not a problem.
Here is the vid of it running:

Are my crank seals the problem? Something else? What do you think makes it run like that.

 

[etemplet]

First thing... remove those screws that are jiggling on the carbs. They will fall right into the intake and go right into the engine.

I'd buy genuine Mikunia kits and needles and seats. Probably $130 in parts. that generally fixes the carbs and that is ALL I use. I don't want to work on them twice. Also order the correct springs, the black ones i think they are 80 gram. All Mikuni. Your pop-off pressure will likely be in the 36psi range.

Did you verify that the 3 small ports in the carb throat are totally clear? To check this the low speed needle needs to be installed and the low speed jet removed. I use lectra-clean or Brake-Kleen with the straw nozzle for this next operation. Open the carb throat and spray into the low speed jet hole. 3 stream should be visile in the carb throat. There is another larger stream you might need to plug with your thumb. If these are not clear... the carbs will not transition.

Good Luck !

 

[mikidymac]

Yes the carbs are a big issue as all aftermarket carb kits are junk.

The bigger issue is a 22 psi difference in cylinder compression. You have a cylinder going bad and needs to be investigated before going further.

 

[JRogers]

Found out the lever must be in forward. Runs fine after that.

 

[Phuck_boi]

Found out the lever must be in forward. Runs fine after that.

What lever?