Bill Posted July 31, 2006 Report Share Posted July 31, 2006 Hi,I bought myself A 1989 banshee and I dont know alot about it thats what brings me here.The way I got it was with A fresh rebuild .30 over,FMF fattys,boost bottle,K@N,and boysin reeds.I have A problem with it bogging on take off then backfiring.But if I keep the bitch sceaming thu all the gears it wont.I took the carbs off and cleaned them good,checked all the rubber boots and intakes for leaks and their fine.I have stock carbs with 230 mains,im not sure what size the other ones are.I checked the plugs and their both dark.Im lookin for some good tips,it will be well apreciated thanks Quote Link to comment Share on other sites More sharing options...
gregbowler Posted July 31, 2006 Report Share Posted July 31, 2006 What's your elevation ? 230's sound lean unless your over 4500ft. Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 im not sure what the elevation is,I live in Michigan. Quote Link to comment Share on other sites More sharing options...
liquedfire Posted July 31, 2006 Report Share Posted July 31, 2006 do a compression test cold then let it run for a bit and do it warm then post the p.s.i u read on your tester Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 what should my compresion be at? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 31, 2006 Report Share Posted July 31, 2006 Our elevation in MI is less than 1000 feet. You are LEAN on your main jets, period. With the airbox and no lid you should be around 270 to 290 mains, with no airbox and just clamp on filters, you should be in the 320 to 350 range. Stop riding that bike now. Fresh build, stock head and stock porting, you should be in the 130PSI range, give or take. Cold will be a few PSI less...maybe. Make sure to hold the throttle WIDE OPEN when checking compression, and don't stop kicking until it stops. It often takes 10 to 15 kicks to get a true compression reading. Where abouts you at in MI? Also, what kind of oil are you using, and what premix ratio? Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 im sorry I goofed on the main size, they are 280s.Should the slides in the carbs close completely when I let off the throttle.their not stickin im just thinking their out of adjustment ,thanks I stay in Kawkawlin,the oil I been using is Klotts techplate2x at 40 to 1.I use NKG race plugs and their black. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 31, 2006 Report Share Posted July 31, 2006 Carbs being out of sync can cause crappy running before WOT (where they're both wide open) 280s is more like it. Put some old run of the mill BR8ES plugs in there....gapped at .028. Oil and premix are fine. They should slam shut, but there should be a little gap on the motor side of them. That's for idle. Your gap may vary for idle needs, but....it can be 1/8 inch or so...normally. Next...remove the air filter, and adjust the carbs to make sure they open in unison. There's a tool called a syncrometer that make sure each is adjusted properly...do a search here for it.... Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 the plugs are wet at idle,at higher rpms their sooty dark brown black.should I try moving the e-clip up?is there any way to syc the carbs without the tool? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 31, 2006 Report Share Posted July 31, 2006 you can sync them by eye...I always do. But, the tool is nice to have. Let's start over. What size pilots are in there? What is your air screw at? Your needle does not effect idle. Pilot jet and air screw do... Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 I dont have a clue what size pilots are in there,my screws are turned out 2 to 2 1/2 times.How do you sync by eye?thanks Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 31, 2006 Report Share Posted July 31, 2006 Remove the air filter. Look down the back of the air box at the back of the carb throats... Move the thumb throttle slowly, and make sure the slides move at the same time. If they don't, there's a 10mm lock nut and 8mm sleeve you turn up or down to sync them. Lock the lock nut down when done. Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 thanks alot for the info ,time to get to it! Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 31, 2006 Report Share Posted July 31, 2006 Where in MI are you at? Quote Link to comment Share on other sites More sharing options...
Bill Posted July 31, 2006 Author Report Share Posted July 31, 2006 I live in Kawkawlin/its near Bay City.well I took the air filter off and synced the slides with A 1/8 in gap when down.The pilot scews are 1 1/2 turns out ,its a little better.It doesnt backfire anymore but still boggs.I did not change the old plugs,do you think thats the prob.thanks Quote Link to comment Share on other sites More sharing options...
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