1998 seadoo challenger adnormal WOT

[hoodmekanik]

i have been working on this boat for some time... i have changed 4 spark plugs BR8ES many times ... new coil packs... new spark plug wires... new rave diaphrams and gaskets... cleaned rave slots... new fuel filters... 4 mikuni rebuilt kits... carb dipped all 4 carbs... blew compressed air through all the holes and passages... everything comes out clear... and all 4 cylinders have 150psi

my problem is now that both engines are idling perfect in the water at 1500 rpm... when i throttle up both engines at the same time.... the port side engine runs great, throttle response is quick but the starboard engine revs up slowly to about 3k and than pegs to 7k rpm, now both engines are pegs at 7k rpm for about 15 secs and than the starboard engine loses power to 5k rpm and stays there... now if i throttle down than open throttle again both engines peg to 7k rpm...

ive also slowly throttled up to wot each motor and they will stay at 7k revlimit for 30+ secs with no problems

now when the starboard engine drops rpms at wot i drop the throttle on the portside engine and the starboard engine starts to increase rpms.... so i can throttle down the portside engine and have both engines run at max 6k rpm and have consistent power...

any ideas

my carb settings are 1.5 low setting high setting 1/8 turn

 

[USAF_Pride]

Shot in the dark: regulator?

 

[hoodmekanik]

where is the regulator... is it in the carb

 

[Sportster-2001-951C-Stock]

He's thinking of the voltage regulator, the voltage rectifier regulator can sometimes cause RPM issues if it's not working properly for some reason.

I guess above you're saying there's something causing crosstalk between engines. This could be electrical or fuel related, what are the components in these two systems which are common to both?

The voltage regulator is probably common to both, no?
How about the fuel pump, are there two of them? If yes, then how about the fuel supply from the tank, is it partially clogged or are there any small air leaks in the lines which could allow the fuel pumps to suck air into the fuel lines? The o-ring seal at the top of the water separator cup is famous for causing this.

If one of your engines is running out lean falling on it's face, you might scorch a piston, so be careful with that.

Could be you have an exhaust leak, and the bilge is filling with carbon monoxide.