ITFD Posted June 9, 2012 Report Share Posted June 9, 2012 I got my 87 running after a full restoration and rebuild. It seems to be running real rich though. It has stock pilots, 220 mains. Its bored .020 over and has Bills pipes with powercore silencers. It starts, idles, and off idle is great but studders all the way up through the powerband after that. I raised the slide needle one notch and made it worse. The plugs are dark up inside the porcelin and they are wet. My elevation is 2400 and average temps are about 70-80 degrees. Than in advance.. Quote Link to comment Share on other sites More sharing options...
maskmanLS6 Posted June 9, 2012 Report Share Posted June 9, 2012 I got my 87 running after a full restoration and rebuild. It seems to be running real rich though. It has stock pilots, 220 mains. Its bored .020 over and has Bills pipes with powercore silencers. It starts, idles, and off idle is great but studders all the way up through the powerband after that. I raised the slide needle one notch and made it worse. The plugs are dark up inside the porcelin and they are wet. My elevation is 2400 and average temps are about 70-80 degrees. Than in advance.. It might have aftermarket needles in the carbs which are shorter with a different taper than stock. If so they can make your mixture rich. Try cleaning the carbs real good first, make sure you spray through the pilot passages including the tiny one thats at an angle you can see in the carb barrel. You need to remove the jets before you spray, and also take your choke plunger out and spray the passages for it as well. Dont be greedy with the carb spray, then try the bike again. If the problem is still there then try lowering your needle one clip position. If that improves it but doesnt completely fix the problem then keep moving it down until it gets to where your happy. And i would recommend a 250 or 260 main at least. After you get it running like you want it to then do a plug chop to make sure your mixture isnt too extreme either way. Quote Link to comment Share on other sites More sharing options...
dave5.0 Posted June 9, 2012 Report Share Posted June 9, 2012 What are you runnin for an air box? Stock carb needles? Stock carbs? I would think your mains would be way richer like he said. Maybe you have other issues. Those your only mods? Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted June 9, 2012 Report Share Posted June 9, 2012 Are you sure you moved the needle the correct way? If you move the clip down it gets richer and if you move the clip up it gets leaner. Seen many people move the clip the wrong way. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted June 9, 2012 Report Share Posted June 9, 2012 It might have aftermarket needles in the carbs which are shorter with a different taper than stock. If so they can make your mixture rich. Try cleaning the carbs real good first, make sure you spray through the pilot passages including the tiny one thats at an angle you can see in the carb barrel. You need to remove the jets before you spray, and also take your choke plunger out and spray the passages for it as well. Dont be greedy with the carb spray, then try the bike again. If the problem is still there then try lowering your needle one clip position. If that improves it but doesnt completely fix the problem then keep moving it down until it gets to where your happy. And i would recommend a 250 or 260 main at least. After you get it running like you want it to then do a plug chop to make sure your mixture isnt too extreme either way. Aftermarket "stock carb" needles ARE NOT shorter than the factory needle. Toomey/dynojet needles are LONGER than the factory needle. They are thinner ,but not shorter. just an FYI. I've had them side-by-side and measured them. Quote Link to comment Share on other sites More sharing options...
ITFD Posted June 9, 2012 Author Report Share Posted June 9, 2012 The airbox and filter are stock and the lid is on. No other mods except the pipes and bored out. I don't think there was any changes made to the carb by the previouse owner. When I moved the clip I moved it down one notch to richen it up some, I will try cleaning the choke out. The rest of the carbs were thouroughly soaked and cleaned. I was told by my Yamaha dealer to run the 220's but leave the pilots. BTW they have never seen a Banshee other than pictures so they are not much help. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted June 9, 2012 Report Share Posted June 9, 2012 Banshees come stock with 200 mains and 25's pilots. Put the needle in the middle groove. Air Screws at 1.5 turns out from closed. Put new B8ES plugs in it gapped to .028". Make sure the carb slides are installed correctly. The left slide will have a thin groove running vertically with a small dot up and just to the left of the groove. The right slide will have the small dot opposite the vertical groove. It's easy to mix the slides up and still align the grooves of the slides to the tabs in the carb bodies. With the motor off and the throttle pinned WOT, you should be able to see the small dots thru the little round windows on the right side of the carb bodies. Pull the airbox lid off and run it. If it still runs like ass put the needle clip in the 4th groove from the pointed end. But my money is on reversed slides... Quote Link to comment Share on other sites More sharing options...
ITFD Posted June 10, 2012 Author Report Share Posted June 10, 2012 Checked the slides, they are in correct. I moved the clip to position 2 and it helped a bit. BTW how long should I run it to get a proper plug reading? Does removing the air box lid make much difference? Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted June 10, 2012 Report Share Posted June 10, 2012 It'll allow more air into the motor and help correct your rich condition. Quote Link to comment Share on other sites More sharing options...
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