As Mike said, IF it's the original engine.......
Remove the main Jet adjuster (1/2" wrench on the bottom carburator. It looks like a bolt with a smaller bolt screwed into it... the smaller bolt having a spring wound around it. Goes into the bottom of the carb at about a 45* angle). Once that's out, stick a medium sized flat head screwdriver in the hole and remove the actual Jet (it is brass so be careful with the screwdriver). clean the inside of the Jet with carb cleaner, or soak it in acetone overnight. Also spray carb cleaner into the hole where the Jet was removed. Once it's clean, reinstall all the parts. the smaller bolt in the jet adjuster (actually a screw) is the main fuel adjustment on that engine. use a screwdriver to run it in (GENTLY) till it stops. then back it out one and a half turns. also of note, once the adjuster is removed, Fuel should run out of the hole. If it doesn't, something is clogged... refer to H-Mikes post. If fuel does run out, let it run for a minute or two before stopping it with either the fuel shutoff, or a pair of vice grips on the fuel line to pinch it closed. your problem might be as simple as old gas in the carb.
If this doesn't get you going, let us know and we will try other things Where are you located? chances are there is a friendly 6x6world member near by who would be glad to lend a hand
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