WantABanshee Posted February 10, 2013 Report Share Posted February 10, 2013 I recently rebuild a banshee and completely went through and rebuilt the carbs. I read a few topics on here where people had this same problem but didn't see a documented solution. The choke carb has the correct bowls, the middle plastic tube is present, the floats are 21mm without gaskets, and the slides are facing the correct way. The banshee will not start without spraying gas in the carbs. Once it starts it runs great with plenty of power. Fatty pipes with no air box lid. Main jet is 310 and pilot is 25 at 1 turn out. Obviously the bike is not drawing fuel on startup. Compression is good. Any suggestions would be great. Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 10, 2013 Author Report Share Posted February 10, 2013 Stock needle at 2 position as well Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted February 10, 2013 Report Share Posted February 10, 2013 elevation and temp? 310 main an a 25 pilot seems way off. also stock needle? and second clip from the top or bottom? Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted February 10, 2013 Report Share Posted February 10, 2013 like shee rider said....your jetting seems off. For just FMF fattys (granted it does depend on temp/elevation) (say 1100ft and 70*) then you should be around a 260-270 main. With the no airbox lid i'd jump it to say 270-280. Then also you should be around a 27.5 pilot and air screw at 1.5-2 turns out. Needle on the middle clip. Try that. Have you also tried doing a leakdown test? may have a leak that's causing such a lean condition that your having to use extra fuel to help it fire. Clean out your choke circuit? checked your choke needle? And are you sure you have the choke tube inbetween the correct nubs on the carb? Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 10, 2013 Author Report Share Posted February 10, 2013 I knew the main jet was alittle fat but wanted to get it up and running. Needle is 2 notches from the bottom. Do you guys have a part number for a grommet that can be used to plug the ports? I have 27.5 pilots but thought it should run with the 25's. Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 10, 2013 Author Report Share Posted February 10, 2013 Needle is in the 2 notch from the bottom I mean Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 10, 2013 Author Report Share Posted February 10, 2013 What specifically should I look at on the choke circuit? I blew out the circuit and checked the choke know and needle and looked ok Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted February 11, 2013 Report Share Posted February 11, 2013 you cant block off the nubs on the carbs. There has to be a hose between the two nubs that are in line with the choke plunger. The stock banshee carbs use vacuum pressure to initiate the choke on the right side carb. Without the tube you will only have one carb trying to choke a twin cylinder bike. There have been times that I have seen the jetting so close to being too lean (on the pilot jet) that it wont start. To check the choke circuit, pull the plunger, clean everything inside and make sure the choke needle and the seals on the plunger look alright. Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 11, 2013 Author Report Share Posted February 11, 2013 thanks for the info Jereme. You must have mis read because I did not state the hose was blocked off. It is in place and functioning. I have some 27.5 pilots I can put in but I just feel it should start with 25's. Quote Link to comment Share on other sites More sharing options...
bluebanshee98 Posted February 11, 2013 Report Share Posted February 11, 2013 colder air is denser... more air=more fuel needed. as you stated in your first post " Obviously the bike is not drawing fuel on startup" so give it more fuel and make sure it gets it. make sure the 27.5 pilots are clean and throw them in. your gonna need to run them anyway with the fmfs. have you also tried turning up the idle screws? anyone can throw in the biggest pilot in the word but if your idle screws are not where its suppose to be your gonna have to give it gas to start it. its very easy to over look the lil simple things Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted February 11, 2013 Report Share Posted February 11, 2013 I was referring to where you asked if anyone had a part # for a grommet that could block the ports. I thought you were mentioning blocking the choke ports on the carbs lol. Also you may want to make sure you dab a little sealer around the choke plunger itself where it seals to the carb (there have been a few guys that have had an air leak there) and check your choke tube for leaks. Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 12, 2013 Author Report Share Posted February 12, 2013 I'm gathering up some parts to do a leak down test an then I will put back in the 27.5 tomorrow. We will see what happens ill keep the forum posted Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 14, 2013 Author Report Share Posted February 14, 2013 Found a significant leak between the reed cage and boot. Sealed it up and hopefully will solve my problem! Quote Link to comment Share on other sites More sharing options...
WantABanshee Posted February 16, 2013 Author Report Share Posted February 16, 2013 Put everything back together today after fixing the large air leak on the right side. It help 6psi for an easy 6 mins. Still needed gas spray to start but it idled and ran 2 times better. I'm going to put the larger pilots in and put a new set of plugs in now that the air leak is fixed. Hopefully this has fixed the no start. Quote Link to comment Share on other sites More sharing options...
D.N.K Posted February 19, 2013 Report Share Posted February 19, 2013 Put everything back together today after fixing the large air leak on the right side. It help 6psi for an easy 6 mins. Still needed gas spray to start but it idled and ran 2 times better. I'm going to put the larger pilots in and put a new set of plugs in now that the air leak is fixed. Hopefully this has fixed the no start. some one already said this, but try adjusting your idle. Happened to me when I was tuning. It would only start if I held the throttle a little, hence the slides being adjusted to far down. good luck Quote Link to comment Share on other sites More sharing options...
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