G'day wce,
Did you get any joy with this?

I have also just (yesterday!) bought an Alroh 20" split roller mower. I haven't tried running it yet because the fuel tank looks grubby/rusty(?) and I want to clean it thoroughly before use. When simply pushing it the right section will only roll forwards but locks up when trying to pull it back. I'm new to these mowers so if you have gained some understanding of what is going on it will probably help me. Cheers,... in anticipation!