Engine starts, then dies...

[mark in da soo]

Greetings all,
I purchased a 1990 kitty cat for my son this summer and was giving it a once over this weekend. I had started it probably 10 times since I bought it and it always ran just fine. I decided to drain the old gas since it smelled like varnish and had probably been in the tank for years. I pulled the gas lines and filter, drained the gas, and replaced the lines and filter with new ones. That is all I did. I made sure there were no bubbles in the gas lines and tried to fire her up. Now, it will start after about 5 to 10 pulls but will only run for about 5 seconds and die. I have been toying with it for about three days cleaning the carb, etc. It will only start if I dump a little gas right in the cylinder and pull, but after a few second, bam, it dies. I have not checked the compression but it sure feels like it has plenty. What's going on????
Thanks for any help!

[Engineer]

First start by eliminating potential cause. Do you still have spark at the plug? Is there fuel in the float bowl? If it fires and runs for a few seconds, I don’t think it is a compression problem. Is the choke on or off when it fires? It should be off when try to fire it after you prime the cylinder. Where did you set the mixture screw? Two cycle carbs can be very finicky. It sounds like it runs on the fuel you put down the cylinder and is not drawing fuel from the carb. Check to see if there is fuel in bowl by loosening the bolt on the bottom of the bowl. If you have fuel in the bowl, you may have loosened some dirt when you were working on it and it has plugged one of the circuits in the carb. The kitty Cat has only two circuits, idle and high speed. Make sure both circuits are clean by forcing air through them. The idle circuit ends with two small holes on either side of the butterfly valve. These holes are usually the problem with the carb when most two cycles will not idle or run rough. I have seen where people keep adjusting the carb to keep it running on bad fuel or when the carb is partially plugged. Then when it is cleaned up, the carb has to be completely re-setup. Clean and check all the circuits, set the float height, and set the mixture screw to 1-¾ turns out from lightly seated. Let us know what happens after this.

[mark in da soo]

Thanks for the info. I suspect it may be loosened dirt in the carb. I will clean the circuits as soon as I find time....
Will let you know how it goes!

[mark in da soo]

Thanks for the help!
After taking apart the carb I found that the float was sticking. Cleaned her up and she runs like a charm again!