Rescuejeff Posted February 19, 2004 Report Share Posted February 19, 2004 I need some help from all of the smart folks out there, I have a 89 stock motor Banshee that has less than 10 hours on the top end and it ran fine but is having issues now. It has been getting harder and harder to start with a decrease in performance. When riden it it comes to a hill and acts if it will get up the hill and falls off the powerband really quickly, and you have to downshift in spots I have never had to before. Friends have suggested a CDI unit, but I'm not sold, big investment if that is not the problem. I have FMF fatty pipes with the jet kit that came with it, and K&N airfilter with outerware prefilter, the top of the air box is off, plus throttle stops are removed and no other mods. Is there someone that might be able to help me find out what the heck is going on. Thanks. RescueJeff Quote Link to comment Share on other sites More sharing options...
bbluebanshee Posted February 19, 2004 Report Share Posted February 19, 2004 check plugs, do a compression check, also check your gas. that is a start! has the performance been desreasing gradually, or all at once? Quote Link to comment Share on other sites More sharing options...
boonman Posted February 19, 2004 Report Share Posted February 19, 2004 It sounds like your lean. Judging by your explanation that it "sounds like it will go" but then falls out of the powerband tells me something isn't right with fuel delivery. "zingy" revs and not having power is a sure tell tale that you are lean. Like the bike seems to rev alright, but when you need the power, it just is't there. You may have clogged a jet, or partially clogged it. And if it has been this way long enough, you may have melted your new top end down already. You need to clean the carbs, and check your jetting. Did you change anything since you got it? Like pull the airbox lid? change air filters? Elevation? Temperature change? the air is colder now and more dense. This will lean everything out.... You need to post your jetting info. Such as elevation and where you are at now. You can check out the Banshee jetting FAQ. I doubt it is electrical..... Quote Link to comment Share on other sites More sharing options...
BenBB Posted February 19, 2004 Report Share Posted February 19, 2004 I doubt it's the CDI, typically they are either go or no go (not always), so I would save that for last after you rule everything else out. I agree with bbluebanshee, I would check compression first, the symptoms kind of point towards low compression...did you break it in after the rebuild? If that checks out move on to jetting and carb cleaning as Boonman suggested, the pilots in particular have a very small opening and it doesn't take much to clog them. That alone would make it hard to start but may or may not affect performance as much as you indicated. But being too lean on the mains will compound the problem. Good luck. Quote Link to comment Share on other sites More sharing options...
Rescuejeff Posted February 19, 2004 Author Report Share Posted February 19, 2004 I have checked the fuel and it's not that, the plug color is light brown like it should be. It revs fine but has the the starting issues and falling off at power band usage. Thanks for the ideas so far. I have not tore the carbs apart yet but I'm buying large polits just in case, to try helping the starting issue and compression check is the first thing I'm going to do once I get back from the Winternationals on Sunday. Plus yes I did brake it in when I rebuilt it. Quote Link to comment Share on other sites More sharing options...
SDD Posted February 19, 2004 Report Share Posted February 19, 2004 What main jets do you have and at what altitude are you riding? Quote Link to comment Share on other sites More sharing options...
Rescuejeff Posted February 19, 2004 Author Report Share Posted February 19, 2004 SDD, I have the 280 mains from FMF that come with the pipes and ride the Imperial sand dunes area like you. Quote Link to comment Share on other sites More sharing options...
BenBB Posted February 19, 2004 Report Share Posted February 19, 2004 280's are probably lean with the K&N and no airbox lid, assuming 32:1 premix ratio. Might want to consider starting with 320's and working your way down until it doesn't bog at WOT, that is if the compression checks out and you make sure the pilots are clean (you could probably go straight to 30 pilots). Good luck. Quote Link to comment Share on other sites More sharing options...
sredish Posted February 20, 2004 Report Share Posted February 20, 2004 280's are probably lean with the K&N and no airbox lid, assuming 32:1 premix ratio. Might want to consider starting with 320's and working your way down until it doesn't bog at WOT, that is if the compression checks out and you make sure the pilots are clean (you could probably go straight to 30 pilots). Good luck. Yep, I was running 310 main and 27.5 pilot with the airbox lid and a uni filter. with vforce reeds also. Quote Link to comment Share on other sites More sharing options...
Ducman Posted February 20, 2004 Report Share Posted February 20, 2004 Yup - U R lean I have the Gnarlies and a foam filter with the air box lid off, 400' elev. , temp 50 degrees, #30 pilots and I am perfect at 290 mains. I'd say you'd be jetted correctly at 320 or even 330 mains with the K&N and lid off. The jets that come with the pipes are for the stock filter and the airbox lid on at around 80 degrees. My Gnarlies came with a kit that said they were for Fatties with a #260 main. Quote Link to comment Share on other sites More sharing options...
Rescuejeff Posted February 20, 2004 Author Report Share Posted February 20, 2004 Ducman, I will start looking to what you have since we are from the same state and have similar set ups. I will post on Sunday any new things when i find out compression and get the mains and pilot jets in. I run Maxima Super M at 32:1, with 2.5g of Avgas, and 2.5g of super unleaded. Nice little trick I found from friend. I will be checking back to you all on Sunday and tahnks very much for your help. Quote Link to comment Share on other sites More sharing options...
Rescuejeff Posted February 23, 2004 Author Report Share Posted February 23, 2004 I have good compression,. I'm getting the new jets as soon as tomorrow, If anyone has a similar set up that goes to glamis could you get me the specs thanks. Quote Link to comment Share on other sites More sharing options...
SDD Posted February 23, 2004 Report Share Posted February 23, 2004 I believe FMF sends 260 mains with their pipes. With it being so cold in the dunes the last few months you should be jetted richer than 280s with an open airbox. You should be right around 300 mains and 30-32.5 pilots. When you say the plugs look fine was that on a full throttle run? You will get good looking plugs from just general riding through the dunes but you could be lean at full throttle. If you need more help let me know... Quote Link to comment Share on other sites More sharing options...
Rescuejeff Posted February 23, 2004 Author Report Share Posted February 23, 2004 SDD, sorry for not noticing that fact you where a local, Thanks for the help I'm on the way to buy some jets to range 280-320 to help fix my, issue and change the pilots out. The plugs looked fine after riding around, I forgot about the flat out and shut down to get a better reading on the plugs. Quote Link to comment Share on other sites More sharing options...
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