Ensign carb adjust on Cat 10

I recently rebuilt my Cat 10 carb with a kit from a member. No more flooding and no more leaks, but now it won't start. Can anyone help with any basic adjustments (hot, cold idle, etc.)? Many thanks for your help and a happy 2014 to all. Robert

details on carb: http://www.acmoc.org/bb/showthread.php?12628-Cat-Ten-Carb-Rebuild-Begun
carb adjustments in post #4: http://www.acmoc.org/bb/showthread.php?9699-ensign-carb

I went through what you're going through a year ago and last week once again on my 15 with the same Ensign carby. It had sat for a year and in the process at some point, I had put the needle valve in upside down. I had to add a piece of cork gasket under the brass arm plus re-bend the arm to get the needle valve to seat and not let gas run all over. I finally got the thing to quit leaking and now it runs fine.

On the original start last year, I was told, that you need to put some gas into each primer cup to help it start. I was also told (correctly) to use some ether. If the timing is right, these two little options help to get it started. Mine now starts nearly everytime on the first crank.

Good luck with it!

Happy New Years everyone!

Jan

Robert,

Those Ensign Carburetors can be a nightmare with the way they are designed...but they are very basic.

The links Erik provided have all the precautions when rebuilding. Remember that the main mixture needle and seat control fuel. So turning it out will richen the mixture. But the idle mixture needle and seat control air. So turning it out will lean your idle mixture. I have found that the old rule of thumb when initially setting up a carburetor of 1 1/2 turns off of the seat, still works pretty good to get you started. But remember too that the condition of the engine will dictate what your settings will be. By condition...I mean compression, valves and seats, carburetor condition...etc. Mine was a full rebuild on the engine and carburetor, so once I got the gaskets correct on that center pedestal, she starts and runs just fine!

On a strong engine with good carburetor...you will never need the primer cups unless the outside air temp is very cool. Even after sitting long periods of time, I simply pull the engine through two times with full choke and magneto off. Switch magneto on and pull again with full choke...95% of the time it will start immediately. Each engine will be different and it just takes time to figure out what works best for yours.

Like all gas engines...let it warm up to operating temp before you make any adjustments to carburetor. And make sure your choke is completely off when you do adjust. Just make small adjustments at a time...no more than a quarter turn of the mixture screw. Listen for increase or decrease of RPM. You always want highest RPM and highest Vacuum...but since there are no vacuum ports...highest RPM will do.

I think you will find that on the idle circuit...the idle screw really isn't effective after a certain point. This engine and carburetor were never meant to run over 1500 RPM...so there is not much of a crossover circuit, no accelerator pump, no air correctors...etc...pretty basic...mix air with fuel...deliver to combustion chamber, spark and bang!

Good Luck and let us know how things go!

Pat