I have a Mxz 670 1997 with stock fuel pump. Pumps to only one carb. Motor has 150 compression each side. New pulse line and fuel lines. I have tried a pump from a 98 mxz with same results, fills line to one carb and very little to other. I am thinking low crank case pressure as diaphram in pumps hold pressure and inner valves seem normal.. Has anyone experienced this with this model? Thanks Sanford

When you state you are not getting enough fuel to one carb, are you checking this with the fuel lines attached to the carbs , or are they off ? I would check the fuel dilevery by running the engine with the fuel ines off both carbs and placing the lines in a container of some sort and watch the fuel flow on both line at the same time. the engine should run for a minnute or so with the fuel in the bowls. If the fuel flow out of both line the same, I would think there is a restriction of some sort in that carb. Maybe a stuck needle and seat, or a piece of somthing in the passage way to the seat.

When you state you are not getting enough fuel to one carb, are you checking this with the fuel lines attached to the carbs , or are they off ? I would check the fuel dilevery by running the engine with the fuel ines off both carbs and placing the lines in a container of some sort and watch the fuel flow on both line at the same time. the engine should run for a minnute or so with the fuel in the bowls. If the fuel flow out of both line the same, I would think there is a restriction of some sort in that carb. Maybe a stuck needle and seat, or a piece of somthing in the passage way to the seat. BrookR.. Thanks for your opinion . I will reclean that carb making sure to remove fuel inlet needle and seat and shooting compressed air opposite fuel flow. I will put a plastic bag over the inlet spigot to see if anything comes out, The outcome will be known to you. Thanks Sanford

Hello BrookR.. Opened carb, no gas in bowl , needle free, and fuel inlet clean. Blew through seat and put a clean cloth over fuel spigot , no debris. I dont know how much pulse pressure is required to activate pump. I will check the tank pickup line again to see if i overlooked something. Sanford