I have 2 v2 engines. One which Im running a RE11, 7.5mm venturi, bullet P3 plug and 30% fuel. On out fairly tight, very high grip (astro) track, Im getting just over 10mins to a tank. The engine hasnt quite done a gallon yet so is still running a little rich. Tons of torque and it looks like its gonna be a missile down the straight.

However, my second engine which has an OS2050 strapped to it and has only done 4 tanks on the box, is proving to be an absolute bitch! Starts OK, ticks over ok, but as soon as I chuck it down to start doing lazy fig 8's for the break-in, the tickover just climbs and climbs. Cant really do too much tweaking on the box, as its still way to tight.
Went back to factory settings, but didnt seem to make much difference.

Should I be looking for an air leak somewhere? Im going to try the carb from my other engine in it, along with the RE11, see if that helps at all.