Sputtering 45 MB

have a 45 MB that is giving me some trouble. It ran fine then all of a sudden it started spitting and sputtering when accelerating. So I changed the cylenoid in the distributor and the plugs and it ran great.

A month later it statrted doing it again, so i pulled the plugs and they caked with black carbon. Cleaned them and she ran good for 15 minutes and started acting up. Pulled the plugs and 2 of the plugs were black again.

is this from the cold weather cause i drove her all summer with no problems.

any help would be great. THANKS

 

not a pro mechanic, but it kinda sounds like its running to rich. give more info on engine, ext. and these guys can probable help more.

 

If you are running a Carter YF Carb and the float level is ok I would say the pump diaphragm has started leaking.

 

thanks, ill be checking things this weekend

 

choke is not stuck, must be carb runing to rich. I dont know much about carbs in these jeeps. its a carter i know but i dont know how to take apart and check for debri in float and needle area. Im going to change fuel filter and try it.

ThanKs

 

well, changed fuel filter cleaned plugs. Started it without choke and tooka short ride(10min) on hard road no stoping or idleing. Ran fine. i think idleing and crawling help it run rich.

So, I dont know haw to work on carb, but Ill keep playing with it.

Thanks for the Help

 

The YF is not hard to work on, Study an exploded view for awhile to become familiar with the components. There are several things that can contribute to rich running.

At this point I would check the float level and note what kind of fuel valve is in it ( needle and seat ) Is it a rubber tipped needle with a fairly large orfice in the seat or is it a spring loaded metal needle with a small orfice in the seat, The wrong fuel valve can cause flooding. NOTE; If the larger rubber tipped needle & seat is all thats available you may need a fuel pressure regulator between the fuel pump and carb.

Then there is the pump diaphragm, The bottom of this diaphragm is exposed to manifold vacuum. When it starts to fail it will leak fuel directly into the intake manifold. The higher the vacuum the more it leaks, Thus it can flood or run rich at idle but "seem" to run ok at speed under slight load. Being able to start it without the choke, Fouling plugs, Loading up with fuel at idle, Excessive fuel consumption and Hard starting when hot after its been shut down for awhile are all symptoms the diaphragm could be starting to fail.

Let us know what you find