Carb bore for Nova .12 SX

[riggerman]

Set uo Nova .12 SX in my 16 oz rigger had a difficult time getting it over the 30 mph range couple club members said the carb bore was to small its a slide carb with a internal bore of 5 mm run on 20% nitro and a Macs 2.5 cc pipe i looked at my Picco .15 with a K&B 3.5 cc carb with a intrnal bore of 7 mm using same fuel and pipe rigger runs around the 50 mph range . I m nor most people in the local area are not familiar with the Nova .12 SX as it is several years old forgot to mentio n props used are x642- h-4 .Which size carb should i be using for this set up ?Iwould prefer a rotary carb. Any info would be great

 

[izitbrokeyet?]

The 6mm novarossi rotary carb is the way to go on that motor.

I have a new one for $20 if you're interested

 

[Ron Olson]

I got one of Kevin's carbs and gained a good 5 MPH on my .12 mono. It was just getting dialed in when the crank broke. This was with my Trinity/Picco. The ROAR mandated 5mm carbs really slow the boats down. Put a smaller prop on to get the revs up, a Prather 215, an Octura V937/3 or 1440 is the way to go so far. Up the Nitro too, I've run 40-50% in mine.