I have a 1993 Gas Gas 250 that has developed a problem, It`s quite hard to start and when it does it idles ok but if I open the throttle it sounds like it`s hunting and will not rev up then sounds like it runs out of fuel and stalls! I have a spare carb that has just been re done and it does the same with that! The spark looks ok and now I`m lost as to what else it could be! Help anyone? Many thanks.

I have a 1993 Gas Gas 250 that has developed a problem, It`s quite hard to start and when it does it idles ok but if I open the throttle it sounds like it`s hunting and will not rev up then sounds like it runs out of fuel and stalls! I have a spare carb that has just been re done and it does the same with that! The spark looks ok and now I`m lost as to what else it could be! Help anyone? Many thanks.

I'd start by checking that the petrol tank breather (tube on the cap) isn't blocked - try running it with the cap off.

Paul Mac

Edited July 7, 201115 yr by paulmac

It sounds like you have a fuel delivery problem or lack thereof. The motor leans out the instant you open the throttle.

Pull the fuel line off the carb and see if you get a full flow out of the tank with the gas cap on then with it off, you may have a clogged petcock or a clogged vent line or clogged fuel line.

Can you rig up a temporary alternate fuel supply?

Two carbs both haveing the same problem most likley rules out a carb problem.

Bob