fiveohfanatic Posted January 16, 2012 Report Share Posted January 16, 2012 Hello everyone, new to the forum here. Picked up a banshee for my son for christmas and since have been reading left and right about tuning. I also picked up a clymer and checked out the FAQ on jetting. I have been trying to adjust/jet the carbs based on driveability so here goes: Mods are pro-design filter, stock air box, no lid. Stock carbs/reeds, etc. Pro-circuit pipes/304 silencers. TORS delete (mod I did to get the thing to idle and run right). When I first got it, after warming up you could not get it to take off without bogging down. I also opened it up the second day I had it and high revved 2nd and I felt it running lean cause it stopped making power. So I pulled the carbs and completely rebuilt them and deleted the TORS. THIS BANSHEE with pipes and no box lid had 240 mains/27.5 pilot. For the mains i was like WTF?????? The air screws were out almost 4 turns and still bogging. Again, WTF???? I ended up putting 300 mains and backing down the pilot to 25 (not so sure about the pilot size here but due to bogging i went down). I deleted the TORS and syncd the carbs. Air screws 1 1/2 turns out. So now I have still a bit of a stumble off idle, you gotta rev it a good bit to clear up. And since the 300 main, there is a bit of midrange stumble. I am thinking of trying to move the needle to down a spot (4th slot, its in the middle now). The pilot has me truely stumped though, should it be running a larger pilot with pipes/filter/no airbox lid??? I did a compression test, 130/126 on the cylinders. It also takes several kicks to start, almost like its not getting enough fuel. Once again, pilot shows symptoms of bogging off idle but with starting not enough fuel???? Sorry for such a long thread, but after reading 40 or more threads on this I cant figure out how to clean the bog off idle and problems starting. Thanks for any help with this. Quote Link to comment Share on other sites More sharing options...
fiveohfanatic Posted January 16, 2012 Author Report Share Posted January 16, 2012 whats your elevation??? put the 27.5 pilot back in. Make sure that the airscrew seats where filed down enough. how is it top end with the 300's? maybe try going down to a 270 - 280 main. also... I would recommend doing a leak down test as well to ensure you got no air leaks. I am at 750ft elevation (Texas). No leak down test, but did a propane hunt with it idling and didnt find any spots that caused the idle to run up. With the idle kit I got the seats filed down good for the lock nut. Is this what you were referring to for the air screw seats? with the 300 main it pulls like a raped ape into the power band and above with hard throttling, the mid hesitation with moderate throttle has me wondering about the needle. I have several jet sizes, 290/280/270 as I knew it would be a guessing game until I was able to do a plug chop. Quote Link to comment Share on other sites More sharing options...
fiveohfanatic Posted January 16, 2012 Author Report Share Posted January 16, 2012 alright so doesnt seem far fetched.. look at your plug see how they look like. yea where your idle screw goes in.. a lot of people dont file it down enough... you may want to go down a size or two on mains depending on the temps you have... Try richening the needle 1 seat... see how it reacts... ( i say go richer cause your always better off going richer then leaner at first)... if it gets worse.. well then you know you can back the needle down 1 clip leaner then where it currently is now.... where abouts in the throttle position are you that it seems to bog? cause the main does have some bleed effect... that is a quick way of checking for any more leaks... I would still recommend a proper leak down but in most cases that will suffice... Plugs are dark, but not fowling. I just put a new set in as the previous set came with the quad. The bogging is at tip in/take off, 1 - 1/8th throttle. I surely understand the bleed effect and know what you are saying. Its not always one adjustment that will make it run right, it could be a combination. I am going to see if I can get it to clear up with the idle screws. If not I will take the carb off and switch out the main and pilot, going to a 280/27.5, and may richen the needle and see what happens. Quote Link to comment Share on other sites More sharing options...
Bkm2006 Posted January 17, 2012 Report Share Posted January 17, 2012 if your getting a dead bog at 0 to 1/8th throttle its lean. 27.5 start at .5 turn out.. adjust from there .. you may even need a 30p.. i run a 30 in my bike but its ported. 27.5 .5 turn out on the p... needle in middle clip for stock needle.. this should be a good start i say leave the 300 main in untill you do a plug chop... Im not jetting expert but thats my .02 cents .. you wlll get it lined out.. also make sure your carbs are synced.... the difference between close and synced perfect is night and day... i recommend buying a carb sync tool from jeff at f.a.s.t ... best tool i own for my banshee. Quote Link to comment Share on other sites More sharing options...
fiveohfanatic Posted January 17, 2012 Author Report Share Posted January 17, 2012 if your getting a dead bog at 0 to 1/8th throttle its lean. 27.5 start at .5 turn out.. adjust from there .. you may even need a 30p.. i run a 30 in my bike but its ported. 27.5 .5 turn out on the p... needle in middle clip for stock needle.. this should be a good start i say leave the 300 main in untill you do a plug chop... Im not jetting expert but thats my .02 cents .. you wlll get it lined out.. also make sure your carbs are synced.... the difference between close and synced perfect is night and day... i recommend buying a carb sync tool from jeff at f.a.s.t ... best tool i own for my banshee. I will put the 27.5 back in, and adjust the air screws and see what happens. Is .5 turns out enough? at that point its coming into the needle... Jump to a 27.5 pilot as mentioned... and try that out..... then try richenin your needle a clip BKM gave you some great pointers as well Read up on this.. great info here.. and used this as a guidline to jet mine http://www.maultechatv.com/techguides/carbtuning.php Read that and got some more info, I will try above and see what happens. I though it was rich with bogging, thats why I dropped the jet. If bogging off idle can be lean, I will go back with the 27.5. I also order 30's from VITOs just now, as well as some more main jets. I gotta get this thing tuned, hard to teach a 13 y/o to ride with it bogging. Quote Link to comment Share on other sites More sharing options...
Bkm2006 Posted January 17, 2012 Report Share Posted January 17, 2012 If its a hard dead bog thats a lean sign. If its cutting up and stuttering thats rich. 27.5 pilot .5 turn out is a good start. If its hard to start thats normally a sign of a lean pilot also. Try the 27.5 p .5 turn out post back here with results Quote Link to comment Share on other sites More sharing options...
fiveohfanatic Posted January 23, 2012 Author Report Share Posted January 23, 2012 Switched out the pilot jets and set the screws to 1 turn out. I also figured out I had a parking brake sensor problem and not a jetting problem. When I went in the first time to the carbs I did the TORS delete. Last night for the hell of it I went ahead and unplugged the sensor at the clutch handle. No more studder or stammer and bogging. It has a little hesitance here and there with take off but definitely feel this can be fixed with fine tuning the airscrews. Thanks again everyone. Quote Link to comment Share on other sites More sharing options...
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