Help Please 1996 SeaDoo GTX New SBT Engine Carb Adjustment

[Beni]

I recently completed the installation of a new SBT engine in my 1996 SeaDoo GTX. I started the engine on the garden hose last week and yesterday I completed the first 30 minute break in session on the lake. The engine starts easy and idles at approximately 1500 rpms in the water. When I put the ski in the water yesterday I let the ski warm up (at idle in neutral) for 10 minutes. I then put the ski in forward and road at an idle for about 5 minutes and then started easing on the throttle (no more than 10 -15%). Upon pushing on the throttle the ski would bog down and shutoff. I was able to restart easily each time. If I feathered (played with) the throttle I was able to get the ski running at about 15 -20% throttle a few times but each time it acted like it wanted to cutoff. After 30 minutes I put the ski back on the trailer and brought it back to the house. I checked the spark plugs, the mag cylinder plug was dark with oil and wet while the PTO plug looked brand new.When I installed the new engine I rebuilt each carb with SBT kits and checked the pop-off pressure in each. The pop-off pressure in each carb was around 43 psi. I replaced the needle valve and the seat about two years ago in an attempt to get some more life out of the previous engine (which was already losing compression in the PTO cylinder). Since the needle valve and the seat were practically brand new I did not replace them. I removed the oil pump and converted the ski to pre-mix. I am currently running the first tank 10 gallons of ethanol free gasoline plus 32 oz of SBT break-in oil and 8 oz of PWC full synthetic oil. I also replaced the starter with a new SBT starter as the old starter was dead after sitting for two years. This morning just to confirm, I check for spark in both cylinders. Both cylinders have spark.I am pretty certain my issues lies in my carbs. When I rebuilt the carbs I set both on low speed jets on 1 and both high speed jets on 0 (as listed in the manual). My question is where do I go from here? I have work on several cars but this is my first jet ski. My thought is to set the mag carb in a quarter turn to 0.75 and try again (my fear is making the mixture to lean). I have done a lot of work to this point and I want to make sure I am make the right decisions. If I adjust the mag carb, do I need to adjust the PTO as well or can the be set separately? Do you think the low speed jets are the problem or should I remove the carbs and retest the pop-off pressures.Also, I have read a lot about the crank seal issues on the 787. Hoping that isn't the issue here since the engine is fresh right out of the box. But please let me know your thoughts.Thanks

[SBT-Tech 1]

Re: Help Please 1996 SeaDoo GTX New SBT Engine Carb Adjustment

Pop off range spec is 23-43 psi. I have found that 25-30 is best when compression is good.
The synthetic oil is not the best for break-in, it is too slippery to allow piston rings to "scuff" the cylinder walls.
Don't get me wrong, they will still break-in but it may take longer.