allis chalmers ca BIG PROBS

hi i just put a post on about my allis chalmers ca i was reading a book i have a big carb prob. i am geting carbon on the end of the spark plugs i have to run the tractor on hafe choke or its spuders a litel bit and smokes to but hafe choke it runs fine how do i fix the carb and how would i clean the air filter.shoud i get a new carb or is it a simpel fix let me no thank you all

bryan oshea

Not a lot goes wrong with a carb in general, most cases it is not properly set up and adjusted, the float may be set too high or not high eneough, your fuel/air mix screw may not be correct..black deposits on the plugs signals too rich a mixture, perhaps from being choked but the carb needs to be adjusted and ensure the float is not sticking..you most likely do not need a new carb but you definately need to go through the carb according to your manual..I have a CA Allis manual around here somewhere but it could take some time to find it..hopefully someone here or on the Allis Chalmers board will post some info for you.

You may need to take the carb off and at the bottom is a channel that feeds fuel to the main fuel jet..this channel often gets filled with debris and needs cleaned..
I take it that you have already tried to richen it up with the main fuel screw...

Ron.

not saying you don't have carb problems, but i had a similar problem with my coop, went thru the carb twice. it would run fair to good then start screwing up acting like fuel problem and would run decent with some choke. weeks later i was useing it to pull a car around and it died, no spark replaced condenser, spark returned and end of carb problem. it was a weak spark that would fire a choke richened fuel mixture. make sure you have a hot blue spark not a weak yellow or red spark

Take the gas cap off and see if the problem persists.

I had a similar problem on an IH tractor that I bought from a State Park. I must have taken the carb off and cleaned and adjusted it 10 times.

Well, I finally said "Uncle" and took it to the local IH dealership for professional help. Wouldn"t you know it, all the experienced guys only worked on diesels and they assigned a young guy to do the work. About $600 later, they said they replaced the intake manifold and that it was ready.

But it still ran so rich that if would foul the plugs in a day or less. Again I took the carb off and checked it as well as timing and everything I could find.

Next I took it to an independent shop and told them the story. He took the carb off and pulled down a coffee can of spare jets. Took a look at one and said this one looks about right. After installing a different jet in the carburetor, I have a good running tractor. To this day I have no idea why someone would have installed the wrong jet, but it happened to me.

ok grate i will tri that thanks

the spark is good all till the plugs get black i just got a new destributer with electronc points could that b a problem

you have no idea i took it off 12 times last weekend alone i think im going to get a rebuild kit and see what that dose im olny 14 and the man that helps me with all this stuff got a little mad 1 day and left me hanging there im tring my best though im in the process of restoring a farmall h and its going realy good but i have let the CA sit and im dieing to get it fixed. thank you so much hope to here back and i will let you now how i do thanks

bryan

you have no idea i took it off 12 times last weekend alone i think im going to get a rebuild kit and see what that dose im olny 14 and the man that helps me with all this stuff got a little mad 1 day and left me hanging there im tring my best though im in the process of restoring a farmall h and its going realy good but i have let the CA sit and im dieing to get it fixed. thank you so much hope to here back and i will let you now how i do thanks

bryan

Are you sure the coil is not the source of your problem?
Coils can be checked with an ohmmeter or commercial tester.
Why not use an in-line spark tester and observe the spark when the engine is running??
First make sure your plug wires are the original, metal core type; the carbon core ones don't work very well on tractors. Second, find a piece of clear plastic tubing (about 1/4" I.D. and 2" long), then cut a piece of plug wire long enough to go between the coil and the center tower of the distributor cap and cut it in half. Slide the ends of the cut wire into the tubing until they meet in the center. Replace the coil to distributor wire with your new "diagnostic tool" and start the engine. Gradually increase the wire end gap to determine the spark quality. You should be able to easily see if the spark is bright blue and steady indicating all is well. A good system will probably jump a 1/4" or better gap. the spark should be bright blue & "snappy".
This really looks "cool" in a dark shed or at night!!
This will work on either a magneto or battery operated distributor if the coil wire is accessible. You can also try one spark plug wire at a time as a cylinder diagnostic tool.
Try it and amaze your friends with your "electrical diagnostic tool" all for about $1.00 or less.

Just a little issue with >>>>"First make sure your plug wires are the original, metal core type; the carbon core ones don't work very well on tractors."<<<<<<.

It is only magneto operation which does not like resistive plug leads. Coil fed ignition, like on millions of cars, is no different on a tractor.

Regards, RAB

Take the line loose at the carb and make sure you have a full flow of gas.If you do then get a can of 2+2 Gum Cutter and spray a abundant amount in all openings of the carb including taking the drain plug loose that may get the obstruction out.Also make sure there is no water in the gas

Check your intake manifold with starting fluid,may have a smallhole

Other than a gasket and a needle and seat, I don't see where you can have much of a problem in that AC carb..if it is clean, float set right and no air leaks in the intake system..

I see that you said you have a new dist and electronic ignition....
Did the problems start with the installation of that..?
Weak ignition and off-Timing can really be a pain.!!
Bad coils and condensers and bad plug wires can drive you "up a wall"...
Are you SURE you have the ifnition timing set properly..?
Dis-connect the air cleaner tube from the carb, to be sure it is not an obstruction in the filter..(dirt-filled gauze or too much oil)..
How SURE are you that your Gasoline is not contaminated with diesel or something..??
I take it that you are sure you are using the correct plugs...sometimes the best thing is to toss a new set in first..!!
Let us know what you find..!!
Ron.