Brodhead Pietenpol Association

Original Posted By: "Christian Bobka"
Subject: Pietenpol-List: Wanted: Help and possibly partsPieters,Well here I am back on this machine about to ask some more stupid questions. This pertains to the A-65 engine. On the top rear of the carb there is a 2 bolt plate covering the mix chamber. Inside this chamber is a brass disc with several size holes. When rotated these holes align or mis align with corrersponding holes below thus allowing a variable of fuel to pass this chamber. NOW. What I want, need and must have is the device to physically adjust this brass disc in order to control my mixture to this powerhouse. I had a tough time with that extra fuel problem and the flotation, in case of, but now I realize that some of those towering peaks of the Andes top 20,000. In that case I think I might need to control that mixture from the cockpit.Corky doing all kind of things good and bad in La________________________________________________________________________________

Original Posted By: Michael D Cuy

Original Posted By:
Corky,Inside the chamber should be two discs. One is fixed to the carb body witha slotted countersunk screw that is usually impossible to remove. Youshould then have another brass disc that has a slot in the top. This slotengages a shaft which comes out the top of the little plate you mention (youmight not have the right plate). to the shaft an arm attaches and themixture control bowden cable then attaches to this. the two discs areforced togther with a small spring at the bottom of the shaft.the function of aligning the two discs is to control the pressure of the airabove the fuel in the fuel bowl. If the pressure is decreased then the airpressure above the fuel in the fuel bowl will not force the fuel up with asmutch gusto into the venturi, leaning the mixture.The system works great if you understand the principle involved. Mostpeople to not understand the system and badmouth it. what is it that youare missing parts-wise, not that I have them?Chris----- Original Message -----

Original Posted By: "Christian Bobka"
Subject: Re: Pietenpol-List: Wanted: Help and possibly partsThanks Chris,I have both discs and the spring and a cover plate but no shaft to move that upper disc with the slot and no hole for a shaft. Also maybe this is the cause of difficult starting. That propping has me down in the back.Corky in damp La________________________________________________________________________________

Original Posted By:
Ok corky. If the cover plate has no hole in it then best to just convert itto the nonadjustable carb. Take the cover plate off. clean any old gasketmaterial off. take out the two disks. The sliding disk must come out. itis ok to try to take out just the sliding disk but try to take out all the"stuff" that is in that compartment. The disk that is fixed to the carbbody with the screw probably has a gasket under it. In the end, you shouldsee only aluminum . There is a passage between that chamber and the fuelbowl. make sure it is clear. If memory serves me right, there is anotherpassage that goes to an ambient pressure air source. make sure it is clearalso. If they are not clear, then atmospheric pressure will not push downon the fuel in the fuel bowl pushing the fuel toward the venturi when avacuum in the venturi is present. Make a new gasket the shape of the coverplate and remount the cover plate with the new gasket. That should clear upthe problem here.What you may have had is the two disks sitting in the compartment with asuper lean setting adjusted not allowing the engine to run. Also as you runthe motor the discs could vibrate to different positions changing yourmixture continually. This would be bad. On the other hand the guy thatsold you the motor might have given up on it running right and you got adeal with an easy solution to the problem.By the way, I hope the carb does not have the neoprene tipped float needle.Did you check that?Chris----- Original Message -----

Original Posted By: "fishin"
Subject: Re: Pietenpol-List: Wanted: Help and possibly partsIt DOES have the neoprene float needle tip. It's looking like I might not make it over those 22000 ft passes in the Andes. Best advise me short of abadoning the whole project.Corky lost in carbs in La________________________________________________________________________________