Any ideas on what to do...? (Tamiya Tiger I 1/35 RC)

I have the kit so I know what's there. The turret motor should spin a little when you first turn it on. I bench tested before installation and the motors run without gears fine.
This is what I would check if I had your problem:
(don't mean to sound simplistic, but I know I overlook a lot of obvious things myself).

Brand new batteries, installed the right direction.
unrolled the white receiver cable.
added the antenna to transmitter screwed tighly and extended
turn on trans
turn on tank
you should hear the turret motor whine as a self check

This should work without the tank's metal antenna, just the wire.
My kit will hesitate and do strange things when to batteries run down or because I still haven't rigged my brass antenna, if the wire to trans space is blocked by anything.
Good luck, hope you solve it.

Otherwise try Tamiya USA Monday AM. They are expensive to buy parts from, but I woould think they would take care of a defect or at least help diagnose.

hi john, being a rcbuilder in the past(boats) i don't think there is anything wrong with your engine (never had anny problem in that aria) problebly there is a foult in your receiver or transmitter (or maybe if there's a speedcontroller inside) don't know nothing about that kit , so can't say what inside. put the originale antenna and don't cut the lenght of it ( this can change your transmitting frequency)

My initial inclination is to tell you,, yeah you got a bad motor. Have you got a power supply available to you that you can hook it up to to test it away from the model???

I have never built that model but from what you say it sounds like a bad motor. As far as what to do if it is bad,, Not really sure maybe Radio shack????

I know nothing about the kit, but it might have helped to install each part bit by bit one at a time because that way you could know what the problem was and work with it to fix it instead of putting it all in. Hope it helps...