Who can tell me the strongest starter box. I'm tired of having mine just stall on the compression stroke for any new engine.

I'm breaking in an OS .12XZ and went to geared starters out of frustration on other toys. I want to lose the weight but what box to use.

Tried OFNA with 700 series motor direct drive and 12V 7A, and a Duratrax with 2-540 and a 12v 7A.

Whats stronger????????