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Discussion Starter #1
Since we are on the subject of fouling plugs. I have a 97 Ultra w/ pipes. I had dyno port pipes, no problems. Before any riding last winter I switched to SLP pipes. The sled starts and runs great, but, if I let it idle on it's own when I first crank it for the day, it will foul a plug. usually the pto side, but not always. If I crank it and hold the rpm's at about 2500, it usually is fine. After it's been ridden I can let it idle with no problems. Just on the first start up of the day. I thought, needle and seats must be going bad. I took apart the carbs this fall, cleaned and checked everything. It all looked good, chokes were out a little bit. Leaned out the needle jets as far as I dare. Needles are 2nd from top. I believe I am running 370 jets w/ 390 on pto side. I also have V Force reeds. Any Ideas? Thanks for any help. The sled runs awesome, just this little quirk has me baffled.

Runner
 

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90% of the time fouling is caused by too much fuel. Heres alist of things to check. You probably have done most of them.
Make sure the belt is not a little tight dragging the rpms too low and forcing you to increase your idle screws too far. You can check this by simply removing the belt and starting it. If the belt is good try making sure the machine idles at about 1800 to 1900 rather than the 1500 they usually like to idle at. Next do the drill bit thing to make sure that slide is not higher than the others. Then check for any obstruction in the idle air port of the carb throat. My 96 didnt even have an air jet in the carbs.Now check the Idle air screws. They are probably around one turn. you can turn that one in a little. how about the float has it been checked, might be right on the edge. If nothing else works I have a trick that I learned when I installed my UFOs that I could share with you.
 

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One other thing I dont know what you mean by Leaning the needle jets . Did you actually go to a smaller needle jet. You will need at least a p8 because Ultras are known to have a lean spot in the mid range. I need Q2s in mine. I set them up with my EGTs.
 

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Discussion Starter #4
My idle is set at 1500, I'll bump it up a little. I'll also try the belt. It is an old belt, actually it is too old, but, I'll try it. I have a slight hesitation on take off, so, I let out the air screw 1/4 turn. Can't remember where they are at. My floats were nice and straight this fall. But, I don't have any kind of measuring tools. Yes, we put smaller needle jets in, I'm not sure what they are. p8 does sound familiar. Thanks for the help,

Runner
 
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