Hey Matt, I think what happens is that the left over fuel inside the engine tends to gum up alot and it can make the engine seem seized I bet your pull start was fine just pull the glow plug out and try pulling it over to the get piston moving . Maybe even add a shot of carb cleaner to de- gum it . Just make sure all the stuf is all out and drybefore the plug goes back in .I have cleaned one or two old airplane engines that way and once i was done they were good to go .. PS Be careful not to get any spray into your eyes!!!!!!!good luck