Small Engines (Lawn Mowers, etc.): Arctic cat Kitty Kat, carburetor body, small gas engines

Question
My buddy asked me to look at his little snowmobile for him. Usually I have  no problems fixing small gas engines but this one is stumping me. It is an older Arctic Cat Kitty Kat with a 60cc 2stroke kawasaki. It idles perfect and starts up in a couple of cranks but a couple of seconds after you hit the gas it richens up and tries to die. If you pull the plug after it dies its not wet but covered in black. The low jet is adjusted well since it starts and idles well also it accelerates well for about 2 seconds before it falls on its face. I pulled the carb off and didn't see anything out of the ordinary. I do have a question about the main jet placement in the throat. You want the holes on the brass rod to aim toward the cylinder right. It doesn't seem like its getting too much gas since the plug isn't wet but too little air for some reason. Spark is nice and blue. Maybe there is a timing advance not hooked up or something? Anyway The float seems like its adjusted right and no blockages on the carb but I wish I had a good one I could tear apart and compare it too.

Thanks in advance.
John

Answer
Hello John:

When was this Carburetor Soaked and Cleaned Last? What is the Compression? It May be the Internal Passages of the Carburetor are Restricted by Varnish that Gas Forms Over Time and Soaking is the Only way to Correctly Clean this Varnish Out.  Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl, Float Pin, Float (if Applicable)  and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required. You can View a Breakdown of the Engine at this Site Addy; http://www.buykawpower.com/kmcb2c/main.jsp and Select View Parts Catalog. Now Select 2 Cycle engines and then Select your Engine. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John

Hello Again John:

I Forgot; a Bad CDI Box will Cause the Problem you Described Also. If this Unit has the Older Point Set, then the Condensor May be Bad. Thanks.

Respectfully

John