"Carburetor Cough"
 

I went out this morning in my Model A and drove about 12 miles to a destination. The temp in the morning was 75 degrees. I drove back home in the afternoon (temp @ 92 degrees) and about halfway home was experiencing carb sputter / cough at speed. I could feel the engine heat through the floorboards, so am guessing high temp was a factor. Tried turning the carb mixture / choke rod a bit but got no real improvement while running. I am using a Tillotson carb that tends to be on the rich side. Car never threatened to stall and idled fine - sputter was worse under acceleration. Engine temp was approx 180 when I got it to the garage. I haven't looked closely at the Tillotson internals, but do not see an adjustment for lean / rich fix. Any advice? Thanks, BW

Re: "Carburetor Cough"
 

First check the filter for rust particles, the drop the bottom of the carb and check for the same, Last check the flow from the fuel line, i am sure it is not major thing just junk in the fuel like that is clogging the little jets.

Re: "Carburetor Cough"
 

I suspect that you may have experienced fuel percolation as a result of the higher temperature on the return trip. A number of cars in our local MAFCA club have had that problem and I have made a 3/16" insulator for them to bolt between the carb and the manifold using two gaskets and slightly longer bolts. It worked. I bought the material from McMaster-Carr. WWW.mcmaster.com Gar Williams

Re: "Carburetor Cough"
 

Aerocraft - Can you send a pic of the insulator? I think you have nailed down the problem. I have not had an issue with this car during this summer until today. Temps were high and very high humidity - really felt the heat from the floorboards. Thanks, BW

Re: "Carburetor Cough"
 

Gar can you post an image of that for me also please
thanks
mark
:)

Re: "Carburetor Cough"
 

I have a 1951 Chevy truck (1/2 ton). When I bought it, it would sputter when hot. Found out that the previous owner had changed out the carb but left out a composite spacer between the carb and manifold. Easy fix and I forgot, (CRS), about the correction. I believe a spacer between the carb and manifold is the right answer. Just don't know what the material make up is. BW

Re: "Carburetor Cough"
 

The only example I have left was made from a 1/8" thick micarta type of material. I found that a slightly thicker material worked better and I recommend 3/16". It is simply made to match a gasket being careful to match the interior of the carb / intake manifold throat. I first fly cut the large hole and then, using a good gasket as a template, drilled the bolt holes, and cut the outside dimension on a bandsaw. I dressed the outside edge on a belt sander. It will require slightly longer bolts. McMaster-Carr has a great web site and you can quickly find the material that is easy to work and will take high temperatures. I don't remember the part number. They ship generally same day and will take a credit card. The material is not expensive although you will get enough in a small sheet to supply the entire local club with the insulators.

You may find that there is an interference where the choke rod goes through the firewall once the insulator is installed. We just live with the rubbing. Gar Williams

Re: "Carburetor Cough"
 

Another remedy? Neighbor told me that flat head Ford V8's were prone to vapor lock and his remedy was to put wooden clothes pins on the gas line. Is he pulling my leg? I don't remotely see how this would solve any perc problems. Would they act as a heat sink? :confused: BW

Re: "Carburetor Cough"
 

Say Aerocraft, is that a Pietenpol or Funk? Do you fly it? Could you post a pic or two (after all, it's Model A powered). Thanks.

Re: "Carburetor Cough"
 

May not be the carb or boiling fuel. I'm not a vapor lock believing guy but more a suspect of jet adjustments and carb set-up. Additionally, temp could degrade the spark, as the coil or other ignition parts warm up. Just a thought, forget I said anything.

skip.

Re: "Carburetor Cough"
 

The picture of the airplane and the Coupe shows a single place Pietenpol Scout which I restored a number of years ago. The picture of the engine is of as installed in (two place) Pietenpol Aircamper I once owned. It was my daughter's favorite airplane. She prefered that over our Bonanza. Following are several pictures of the two place Aircamper and the picture of the Scout and our Coupe. Gar Williams

Re: "Carburetor Cough"
 

Cool! Thanks. I saw one at Oshkosh a few years ago and was duly impressed. I'm sure it's a blast to fly.