Cat Twenty-Two Carburation

I can't help with your carb problems but will be watching with interest as I have three 22s.

Here is a link to info on Tractor Fuel as well as recipes-

http://www.steamengine.com.au/ic/faq/powerkero.html

CS

For what it's worth, I have a multi fuel 22 and it runs fine on gasoline. Is the timing off?

This may help. From the operators manual.

The high speed screw should be turned one turn from the closed position for a rough setting, and the idling adjustment screw should be turned one and 1/4 turns from the closed position for a rough setting.

To fine tune:

Turn high sped screw OUT slightly for richer mixture. Located on side of carburetor.

Turn idling screw IN slightly for richer mixture. Located on top of carburetor at an upward angle.

Good luck!

PETE2230
Your 22 should run fine on gas as it was supposed to be started on gas and switched to tractor fuel only when hot enough, so mixing tractor fuel and trying to start it cold is going to cause more problems. The main jet and idle jet are adjustable for both fuels so should work fine no extra jets needed. Chugwater crawlers mentioned the timing and what sparkplugs are you using Old Magnet swears by autolite plugs and I have had major problems with champion plugs. The float level should be close as long as it doesn't have a hole in it ( submerge in hot water and watch for bubbles) Clean all passages in the carb and sandblast if possible use new gaskets when reassembling to prevent air leaks and check the intake manifolds for leaking gaskets. What was the problem with the farmer carb and did this carb create the problem or is it still there?

By the way I have tried all combinations of tractor mix and can't beat good high octane pump gas for pulling power.
Oz22

The engine can start and run like like that, if the spark plug wires are mixed up. 1 3 4 2, is the correct order for the CAT 22. Been there done that. Try putting back the other carb. to confirm nothing else has changed. Bill

Hi Guys - Thanks for the thoughts. Still working on it but just by way of more background. It's running rougher with the Zenith K5A than with the Bendix that was on it with no other changes. The plugs are autolights and I believe with the correct sequence but I'll have to chaeck that tomorrow. The float itself didn't seem to have any holes when I had it apart and I built all new gaskets so I'm doubtul thats the problem. I just keep coming back to the jests but they are both essentially in all the way . It was really bad when I first fired it using the 1 turn open rule. I will have to check and make sure that the high speed and idle are both leaned out as I see they are different. I'll let you all know. Thanks Pete

When and where is it backfiring? Intake or exhaust? There could be one or many reasons for either. .a regular backfire could indicate either timing, valve or plug wire problems.

Generally if an engine is running rich, it'll belch black smoke out of the exhaust but backfiring thru the carb or exhaust won't happen. If the backfire is out of the carb, a stuck (or sticking) valve could cause that. .if it's the exhaust, I'd tend to suspect it running on the lean side. Intake leaks can be hard to track down. .with it running, spray ether around the intake manifold, carb base and any other joints in the intake system. A sudden increase of engine speed will indicate where the leak is. .but check the ignition system FIRST!! A spark could cause a fire!!! Another way (and safer but messy) to check for leaks is to squirt heavy oil on suspect areas. .a sudden decrease in engine speed (and smoking exhaust) would indicate a leak

Another cause could be worn/cracked plug wires, even if the firing order is correct. A dirty distributor cap could cause that too. I'd suggest starting with the distributor. .clean and adjust the points, maybe replace the condenser, check ALL the wiring with a mutimeter for bad connections, carefully clean the cap and recheck the timing, and carefully inspect the plug wires. Fire it up at night with no lights around and look for jumping sparks. .even a good system will show some.

Hopefully this will give you some ideas. .

Yes I've had the same problem.... You have to add Mystery Oil and your jets are probably bad