Sportjet120 - Rich running conditions, poor performance

[palessard]

Hi folks,

120 SportJet here. Was running great until yesterday when we launched the boat and noticed a lack of performance along with running rich conditions (was burning lots of oil and fuel). Couldnt go past 10 mph at 4000 rpm. The engine was running smokier and rougher.

When we came back, we did the following:

• Checked compression, 150 in all cylinders. Didnt blow / damage / no water in cylinders.
• Tested for spark - fine.
• Checked spark plugs - not fouled, but were nasty because of rich conditions. Will replace anyways.
• Checked reed valves - they were fine.
• We recently cleaned the carbs too. I launched the boat once after and it ran perfect. BUT i have a feeling that something might be off there, the rich running conditions.

Now, my theory is carbs, but I know of the systems on this engine (rev limiter, auto enrichner). Also, there is no way to adjust the fuel / air mixture other than the idle screw which seems weird to me?

ALSO: we had the speed sensor OUT of water during the ride - we noticed AFTER. Could this have an impact on the running conditions?

I will look into the carbs this morning, but in the meantime, does anyone have experience with similar issues?

Thanks!