Hot motor - AGAIN!?!

[Cardnim]

Morning guys,

Quick bit of history:
- racing a Cat SX2
- had 2 previous motors - both Speed Passion v3 6.5 - both bought second hand from fellow oOplers
- both previous motors eventually got so hot that the internals melted enough to ruin the smoothness.
- have tried different combos of spur / pinions and replaced every bearing and ensured no fouling on drivetrain.

So.. now to last night.
- decided not to muck around with 2nd hand motors, so bought a brand new SP v3 6.5; fitted last night for my first club meeting with it.
- after first qualifier the motor was up at 80C!
- fitted a make shift heat sink to it which seemed to bring it down a degree or two.
- but Im really scared (and bloody frustrated) that Im about to cook another (£70!) motor in the first couple of race meets.

I have checked everything that I know of - drivetrain, gearing, binding, bearings - but cannot find anything that is amiss.

The timing on the motor hasnt been touched from factory default (which seems to be in the centre of the timing adjustment ie about 5 degrees)

The ESC is a Speed Passion GT2.0 (lpf) which has its timing turned down to zero and the "DRRS" (start boost thing) down to 3 "normal" from a range of 1 - 9 (9 being max).
Tried it on 1 but still getting the heat.

Top drivers both from my club, and from Schumacher and others have offered me help, but I feel guilty constantly going back to them, (and feela bit embarrased too!) but I dont know enough.

...the SX2 just seems so complicated and Im new to this so really struggling to know what to do.

Any (and all!) advice and suggestions very gratefully recieved guys