Tech questions: 93 Polaris SL 650

Problem: Motor bogs down after just 5-6 secs WOT. Poor idle. Hard to spool
up, dbogs vs go to WOT 8/9 times out of 10 when initially giving it
throttle. Believe it or not, this is after a dealer tune up - but no test
drive....compression, ignition etc all ok.

Recent corrective work: SBT add-on fuel pump kit installed (stock pumps
known to lose effectiveness and lean out the feed to the mag side cylinder).
1 carb diaphragm replaced, other 2 in fair condition. Replaced cracked fuel
inlet fastening cap on gas tank where fuel lines go in assuming this bad
seal would cause a tank pressure/fuel feed problem of some sort.

Well, put it in water today: same damn problem. Started ok, idled ok, gave
it throttle, motor hesitated but got it to WOT about 4 -5 times but it never
stays there....10 secs max then drops suddenly to idle or simply dead.

I understand there are several TSBs on these units but am unable to get that
info? Anyone?

Apparently there is also another problem with the fuel pump called an auto
cock which was a vacuum controlled fuel shutoff valve....there is supposed
to be a way to bypass this...anyone know how?

Fustrated!!!!!

Thanks to anyone who can provide help.

Vince