We used to cut 1-1/2" off em (tuners) as we was going up against Junkrudes GT's and ran the 1.87 lower...doggy down low but would walk on out when it got to strung out.
Service school stated 160+ with the additional mods...all you would see on performance boats was your able to run one pitch size bigger. On Posters hull wouldn't see much difference
Pull the carbs as there is debris in lower one. Either high speed is obstructed, float upside down, float level misadjusted or trash restricting needle /seat inlet . Only use new gasket kits.
As long as its a 25/40W and FC rated yer good. Run Quikleen every second tank of fuel. I recommend to my customers the run Quikleen or Yamaha Ring Free and some are using the Quikare additive. Dont know if these additives work but I dont see these engines them till end of year for servicing. And...
Hook a waterhose to water tube and start it ..Let it run 10-15 minutes and maybe heat and engine vibration will cause it to drop out. If not gotta pull he powerhead
