definetely a 28/32, it'll say under the exhaust port, can't make it out in the picture

I just got the 32cc version running on gas/glow with mild porting, all I did was remove some of the finger in the intake port and thinned down the rib in the exhaust port and widened it a little and I'm getting 7500rpm on an 18x8 APC prop, the ring seems shot too, so I know it can be improved on... I'll get pics up once I maiden the thing... oh, I'm running a 32/64" walbro, so that helps a lot, and I added two 1/2" outlets to the muffler