I have a 99 500 Magnum that will idle but wont accelerate at all. It will idle just fine and the choke is working properly.

I started the machine after a long sit (about 6 months ) and it fired right up. Pulled it out and then it just bogged.......

I checked the plug and it is fine.......

I have removed the air cleaner and squirted starting fluid into the air intake and the motor will rev up just fine.........

I changed the fuel filter to no avail and decided to check the pressure of the fuel pump.......It appears to me that the fuel coming from the pump is less than the gravity flow from the tank which doesnt sound right to me but I am a not familiar with a vacuum powered fuel pump........

I took the pump apart to make sure there were no obstructions and it appeared to be clear as I blew air through both the inlet and outlet of the pump......

I have done nothing to the carb. The machine idles just fine and the plug didnt show any signs of fouling to indicate a rich problem....

I do not think that it is a cam shaft problem because the machine does not backfire either at idle or when i squirt the starting fluid through the air intake.....

Any advice would be greatly appreciated.

 

Make sure the slide is free, it works on vacuum not cable pull.

 

Think you have missed the forest because of the trees! Clean carb,probable jet stopped up/and or needle valve varnished,especially if sitting up 6 months. Gas varnishes in less than 2 months without stabilizer. Try this next and see if fixes your problem! Good luck

 

What about the pump........ What should the outlet pressure be?

and could you please expand on the slide ?

 

<div class="FTQUOTE"><begin quote>Originally posted by: mouty75

What about the pump........ What should the outlet pressure be?



and could you please expand on the slide ?</end quote></div>

[img]i/expressions/face-icon-small-happy.gif[/img] Fuel amount from pump depends on vacuum from carb,will just trickle sometimes if line is pulled from carb. If cranking over with fuel line off of carb, should increase flow. If not addressed carb after sitting 6 months,STILL possibly the problem! I havent had maybe one or two pump diaphrams bad in 20 years! BUT anything possible,especially since I'm not there to see your problems! Slide you are referring to is carb slide. Reach in at back of carb and see if slide can be pushed up with your thumb and come back down on its on,if so slide ok! If engine accelerates ok wit starting fluid for awhile and then boggy,sounds like carb jets,needle and seat,etc.

 

What you described about the pump is consistent with what I am seeing so I will pull the carb and rebuild it......

Do you have any suggestion on the best place to buy the rebuild kit?

Thanks for your help

 

May just need pilot and /or main jet cleaned and air passages blown out. If needle and seat/float not varnished and frozen up,Just may get away without any further work. Just sounds like to to me like typical jets stopped up! Good luck

 

I preciate the advice.......Many thanks