'Stalls & spits' sounds like what they term a 'lean' cough. It is not uncommon for the needle valve on the carbs to need tweaking. 6 carbs on that puppy and you'll need to check all 6. Sometimes you need to work from 1 to the others in sequence, and then re-start all over again.
You need to get them in balance and adjusted correctly. You can do it yourself very easily
with a OEM factory service manual, but IMHO do NOT trust a Seloc or Clymer $20 piece-o’-crap “service” manual.
You should contact Andy Jr. (posts by the name SIM) @ Shipland Island Marine, via
http://www.shipyardisland.com/ContactUs.htm . He should be able to sell you a PDF version of the factory service manual for low cost and tell him you are a CP member, also let him know you’re just trying to adjust the carbs. He will need the model and serial number info direct from the OB's dataplate.
Note: If tweaking the carbs don’t cure this, then the motor could be a candidate for a ‘sync & link’ which synchronizes the carbs to the timing advance – a dealer/service task.
With that O2 sensor on that motor, consider adding Ring-Free with each fillup, 1 ounce to every 10-gallons I believe. Do a search on Megabyte's posting for Ring-Free, he's had phenomenal success keeping his OX66 running clean with it.
