Super Jet Losing high RPM only in the water

[dmpus]

Hey guys, me again .. I did a search prior posting, but couldn't find a similar thread. I took the ski to the lake today and rode it for 20mins with no problem, then a friend rode it for 15 mins when the ski starter losing high RPM. On idle it works with no problem, starts right up, when out of water throttle responds with no problem. In the water at full throttle it does not reach high rpm. I checked the spark plugs and they had a little deposit (for a brand new ski with under 10 hours) and the threads were oily (dont know if thats normal).. I did not have spare plugs to try, but those seem to have normal spark. Dealer said to use only premium gas though on the ski it says normal octane.. I've had only 3-4 tanks since i bought it if that could be a factor?

Thanks in advance for your help.

D.

 

[matth113]

Whats oil and what ratio u mixing?

 

[dmpus]

Whats oil and what ratio u mixing?

The OEM two stroke oil from Yamaha store, 1:50

 

[vitalikol]

I had needle stack in the seat in one carb with same result like yours. Cleaned it and run like champ

 

[dmpus]

I had needle stack in the seat in one carb with same result like yours. Cleaned it and run like champ

That makes sense, if only one carb sprays fuel enough up to certain power or full power with no water resistance when the ski is out the water..
Do I take off carb nozzle to clean it?

Thanks!

 

[Tyler Zane]

what ever you do, dont tune when the ski is out of the water. my ski runs much better in the water.

 

[vitalikol]

That makes sense, if only one carb sprays fuel enough up to certain power or full power with no water resistance when the ski is out the water..
Do I take off carb nozzle to clean it?

Thanks!

You have to take carb apart. Take it off completly and inspect / clean

 

[dmpus]

Since Its almost brand new, it is probably better idea to take it to the dealer. I've been curious though, how do they inspect and tune jetskis without putting them in the water?

Thanks!

D.