Onesickcrewcab Posted October 20, 2003 Report Share Posted October 20, 2003 Alright guys first post here but I've been reading posts for a while. I have a 99 Banshee with FMF Fatty gold series pipes, K&N filters with airbox removed, Boysen Power reeds, and White Brothers boost bottle. I'm having problems with the jetting. I ride at sea level ( live about 15 minutes from pismo beach) and I can't get my banshee to stop running lean. I'm running stock carbs. I started with a 300 main jet, 30 Pilot jet and needle in stop position with the air/fuel screw at 1.5 turns. Found out really fast that the main jet was way to small so I jumped up to a 350 main jet and it continued to run lean. So I decided to jump way up to a 470 main jet to see if I could drown the thing and go down from there. So right now I have 470 Main jets, 30 Pilot jets needle in stock position and air/fuel at 1.5 turns and she still contiunes to run lean after the result of a plug chop. I've tried moving the needle clip down 1 and 2 positions from stock to richen it up but that isnt supposed to work at WOT and the results weren't any different. Tried adjusting the air/fuel screw from .5 to 2.5 turns and it still runs lean. The bike has lots of power and no bog on top end but gets hot real fast. The result of my plug chop today with 470 mains, needle one slot down from stock and air/fuel at 1.5 shows that center of plug completely white. ANY IDEAS???? Most people with my configuration seem to be running a 380-400 main jet max according to the many posts I have read. I have no mods to the engine itself as its still on its stock top end. Have a missed something here or does this thing just need a huge jet or possible some bigger carbs??? I run 91 Octane at 32:1 with castor oil.. Any thoughts, ideas or comments appreciated Quote Link to comment Share on other sites More sharing options...
SyNtAxx Posted October 20, 2003 Report Share Posted October 20, 2003 hey, Sounds like an airleak to me. Check all your rubber boots on the intakes. Some people use wd-40 on the rubbers to see if it has an air leak. If it does the engine tone will change. Good luck Nick Quote Link to comment Share on other sites More sharing options...
Onesickcrewcab Posted October 20, 2003 Author Report Share Posted October 20, 2003 I was thinking about that today. I did spray WD40 all around the boots and reed cages and didnt find any leaks plus both cylinders are running identical. I didnt spray the actual boost bottle, but I did spray around the base of it. Its brand new and looked decent but I guess it could be cracked or have a leak. That would explain both cylinders running lean at the same time. I'll have to check that out tommorow. Thanks for the feedback. Its the little things we miss that make life miserable. Quote Link to comment Share on other sites More sharing options...
bignasty1 Posted October 20, 2003 Report Share Posted October 20, 2003 yeh definately sounds like and air leak my friend had a leak around his plug where it got over tightend and could figure out wht it was till the day his bike moved on to a better place.... so dont for get to make sure it isnt the plug its self bein loose... Quote Link to comment Share on other sites More sharing options...
Onesickcrewcab Posted October 21, 2003 Author Report Share Posted October 21, 2003 Alright went out and leaked checked the Banshee again today. Took off the boost bottle and inspected it and it looks good. Put it back on and leak checked her with starting fluid to see if I could get a little rev or motor noise change and nothing happened. No air leaks to be found. Dont know where to go from here except bigger on the mains. Quote Link to comment Share on other sites More sharing options...
Banchetta Posted October 21, 2003 Report Share Posted October 21, 2003 Damn, I've never heard of that before w/o porting.....Is the petcock on the gas tank slightly plugged??? Fuel free flowing to the carbs...Try adjusting the floats in the carbs?? Quote Link to comment Share on other sites More sharing options...
skykingcory Posted October 21, 2003 Report Share Posted October 21, 2003 I'm only running a 340 main with porting, FMF's, and no airbox. Something isn't right somewhere. Sounds like an airleak somewhere. What about the left crank seal? Also what heat range is the plug you are running? I would also check into what Banchetta said! Your carbs may need to be cleaned or adjusted. Quote Link to comment Share on other sites More sharing options...
Onesickcrewcab Posted October 21, 2003 Author Report Share Posted October 21, 2003 I'm running B8ES NGK plugs. As far as the petcock being clogged I'm not to sure about. I know when I turned on the gas and having overlooked that I forgot to put the gas line back on the carbs it flowed pretty dang well. I have an inline fuel filter that I put on when I first bought the bike and I also changed that out incase it was clogged. The floats are at stock spec. 21mm from the carb bowl gasket seat (without the gasket) to the top of each float in both carbs. Should I adjust them differently? Is an airleak in the crank seal a common thing? I could pull that side cover off after work and check that out. Thats about the only thing I havent triple checked yet. Quote Link to comment Share on other sites More sharing options...
Banchetta Posted October 22, 2003 Report Share Posted October 22, 2003 If the crank seal was leaking then it would only be one side that'll be lean. Try removing the inline filter. Maybe the fuel can't run through it fast enough.....especially where the shee is gravity fed.... Quote Link to comment Share on other sites More sharing options...
Onesickcrewcab Posted October 22, 2003 Author Report Share Posted October 22, 2003 I think that might be the problem. Today when i got home I was checkin that out. Took it off and noticed that there was a little plastic lip on the feed side of the fuel filter that could be restricting the fuel flow. You know the kind of plastic lip on a cheap model car that you put together that was leftover from the form. Dont have time to take her out tonight and check it out, but I will let you know if that fixed the problem. Thanks again for all you ideas. Quote Link to comment Share on other sites More sharing options...
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