Good news

In the afternoon spent a couple of hours with my brother setting up the gearbox and testing it - results are encouraging for now. The motor spins freely, no abnormal loading on the motor.

After ''running in'' the boxes we decided to load it a bit to see what happens, so I connected a 1/4" extension to the output shaft and held it in a keyless chuck (like in the photo a couple of posts above). The motor stalled so we increased throttle slowly...I was expecting something to fail but it didn't, the 1/4 extension started slipping inside the chuck.

Loctite 603 doing its job very well in keeping those gears glued on their shafts!

The only flaw I noticed till now is that the large gear on the output shaft wobbles a little bit...

Here are a couple of vid clips from this afternoon : Warning! its quite noisy!!