[Lyndon]

I have a suzuki sierra sj40, 1981 model. It starts and idles ok but needs full choke to take off. Needs full choke on the slightest inclines and even then, at times, I have to put it into 4wd to make it up the hill. Suggestions anyone?

[Jezzer]

It might be a blocked jet, one does low revs and theres another one than lets fuel in when you put the foot down

[UBZ]

sJ40 is F10a and side draft carb. Check the float bowel window , fuel should be at the level line . FSM explains how to set this . Check for air leaks with engine start selective spraying on parts of carb while running, if you have an air leak engine should surge . These are knowen for air leaks around the throttle butterfly . If this all checks out and timing / idle etc are set correct then most likely you have an internal carb problem , ie blocked jets / emulsifier leak etc and you prob need a rebuild of the carb. Not hard to do but be wary there are multiple variants of the F10 carb when looking for rebuild kits