Re: ENGINE STARTS THEN STOPS AFTER 10 SEC.
Can we assume that it restarts without difficulty? That is, what you're really saying is that the thing won't idle until it is warmed up??? ...or ...are you saying that you get it started and can do abslolutely nothing to keep it running for more than 10 second intervals?
Broaden your description just a bit so someone doesn't run off on some dissertation in the wrong direction.
Can we also assume that the warming in low gear is because it will not function in any other gear (as in bucking, sputter, stumble, etc.)?
Sounds like a choke (or some fuel enrichment) problem (this is a pre-injected version, isn't it?).