pondtunes Posted March 4, 2010 Report Share Posted March 4, 2010 Okay 1987 Shee Mikuni Carbs Currently Have 200 mains installed #25 pilots No Airbox Lid, Running K&N Air Filter Salisbury, North Carolina — Elevation: 791 FT (241 M) Temps currently 30-50 degrees, from 70-100 in the spring/summer Everything else should be Stock.. Stock Pipes & Reeds Etc. What jetting do I need to run for this setup? I have a bog at WOT and the next suggestion after cleanings and adjustments is going up in jet size. Thanks in Advance! Quote Link to comment Share on other sites More sharing options...
Banchetta Posted March 5, 2010 Report Share Posted March 5, 2010 Bogging at full throttle for 3-5 seconds or just when you first whack the throttle? I'm guessing when you first hit the throttle. Make sure the carbs are synced and adjust the air screws for throttle response..You might want to bump the mains to 240's for the K&N... Quote Link to comment Share on other sites More sharing options...
pondtunes Posted March 5, 2010 Author Report Share Posted March 5, 2010 Bogging at full throttle for 3-5 seconds or just when you first whack the throttle? I'm guessing when you first hit the throttle. Make sure the carbs are synced and adjust the air screws for throttle response..You might want to bump the mains to 240's for the K&N... if i open it up to 3/4 throttle i get plenty of response and power jumps right in the band... If i crank it on over to wide open it bogs for a few seconds and will backfire. They're synced as best i can without a proper sync tool, and i've got my screws about 2 turns out Quote Link to comment Share on other sites More sharing options...
3lue by u Posted March 5, 2010 Report Share Posted March 5, 2010 Definitely sounds lean to me. I would jump a size or two up on the mains since it is at WOT. My shee was doing the same thing when I got it and it had 215's in it but I had K&N no lid and was a little warmer and a little higher. Quote Link to comment Share on other sites More sharing options...
Banchetta Posted March 5, 2010 Report Share Posted March 5, 2010 Sounds to me like the mains are plugged. You might have a grain of sand or slime in the jet. Blow it out and you'll be fine. I'd still step up the main though for the k&n. Quote Link to comment Share on other sites More sharing options...
GrMeyer Posted March 6, 2010 Report Share Posted March 6, 2010 Okay 1987 Shee Mikuni Carbs Currently Have 200 mains installed #25 pilots No Airbox Lid, Running K&N Air Filter Salisbury, North Carolina — Elevation: 791 FT (241 M) Temps currently 30-50 degrees, from 70-100 in the spring/summer Everything else should be Stock.. Stock Pipes & Reeds Etc. What jetting do I need to run for this setup? I have a bog at WOT and the next suggestion after cleanings and adjustments is going up in jet size. Thanks in Advance! You are way lean if your not running the lid. I wouldnt ride it anymore tell you get some bigger jets in there. I would start with 250 mains needle in the middle air screw 1-1/2 turns from fully seated. Also make sure your carbs are synced or you will have one shitty bottom end. Read up on this as well http://www.dfn.com/benkaren/jetfaq.html Quote Link to comment Share on other sites More sharing options...
pondtunes Posted March 16, 2010 Author Report Share Posted March 16, 2010 Okay got my jets installed, 240, 250, and 260's started out with the 250's and was still leaning out at WOT... Kept running my screws out and all but got rid of the bogging/backfiring. So i went back to the shop and installed the 260's reset everything and started over. I still had to run the screws out further than I think i should so i think i need bigger jets still.. I have a pretty smoky exhaust now but oddly enough the left is much smokier than the right. Im at least 4 turns out on my screws and it runs really well just under full throttle, probably 7/8 you can tell the instant you turn it too far. overall it was running MUCH better. we took a few rides through the trails and came back. ran low on fuel and threw in a fresh batch of premix. Went out for some more rides everything good came back and it acted like it was running out of fuel very high idle.. When I gassed it i got a back fire at anything over 1/4 throttle which really bugs me now! I suspect i may have a clogged jet now!!! I have a new set of carbs with the tors removed as well as a thumb throttle.. Any other theories about what caused my problem at over 1/4 throttle all of a sudden??? Pulled my plugs when i got back in the shop the left is quite oily (it ALWAYS is) and my right plug was black but very dry. Also did a compression test. 108 psi on both cylinders Quote Link to comment Share on other sites More sharing options...
theoriginal87 Posted March 16, 2010 Report Share Posted March 16, 2010 you needa do a leak down test cause it sounds to me like you have an airleak somewhere.. An air leak will cause high idling, one side to richer\leaner than the other, and also make jetting your bike impossible... also check your pick up gap that can cause symptoms like this or a damaged fly wheel so inspect both (had a similar prob and flywheel was bad also incorrect pickup gap) leakdown how to: http://bansheehq.com/forums/index.php?showtopic=110585 for the pickup gap and flywheel: http://www.dfn.com/benkaren/elecfaq.html Quote Link to comment Share on other sites More sharing options...
GrMeyer Posted March 17, 2010 Report Share Posted March 17, 2010 Are you running the lid or not? If your not then your jetting is to lean for those cold temps. If it was mid summer then you might be seeing the 260 mains. If your running the lid then turn the air screws in to around 2-1/2 turns from fully seated. If your not running the air box then the air screws should be around 1-1/2 turn out for starting. FYI the air screws only mess with idle to 1/4 throttle. 1/4-3/4 is needle and WOT is the main. Quote Link to comment Share on other sites More sharing options...
GrMeyer Posted March 17, 2010 Report Share Posted March 17, 2010 Also make sure that your carbs are synced or you will have shitty bottom end. IE one will be working harder then the other. Quote Link to comment Share on other sites More sharing options...
pondtunes Posted March 17, 2010 Author Report Share Posted March 17, 2010 Thanks for the tips... 1) no airbox lid Dunno if theres some other problem here, but i will be checking for leaks as suggested before as soon as my new carbs get here. However; I dropped the 260's in and and had a similar bog at WOT... The more i turned the screws out the more the bog/backfire diminished... I was under the assumption that the screw only affected 1/4 / idle thus idle mixture... However the problem DID get better as I ran them out, im sure my idle is beyond too rich now i've ordered a set of 280 jets do i need to go bigger??? temps in the 60's right now will be 80's / 90's before long Quote Link to comment Share on other sites More sharing options...
GrMeyer Posted March 17, 2010 Report Share Posted March 17, 2010 Thanks for the tips... 1) no airbox lid Dunno if theres some other problem here, but i will be checking for leaks as suggested before as soon as my new carbs get here. However; I dropped the 260's in and and had a similar bog at WOT... The more i turned the screws out the more the bog/backfire diminished... I was under the assumption that the screw only affected 1/4 / idle thus idle mixture... However the problem DID get better as I ran them out, im sure my idle is beyond too rich now i've ordered a set of 280 jets do i need to go bigger??? temps in the 60's right now will be 80's / 90's before long You do have a alot of adjustments for jets. But like anyone. Stock will not always be on a banshee. I would look at getting all the jets you dont have from 260-330. That will provide you with ease of being able to tune the bike and not always wondering if you are lean or not. 2nd note. Turning the air screws in makes them richer. That site i posted up there helps explain how the carbs work and what needs to be done to help you tune them in. What mix ratio are you running? Also, why are you getting different carbs? Are they ones with a TORS kit on them? Quote Link to comment Share on other sites More sharing options...
pondtunes Posted March 17, 2010 Author Report Share Posted March 17, 2010 You do have a alot of adjustments for jets. But like anyone. Stock will not always be on a banshee. I would look at getting all the jets you dont have from 260-330. That will provide you with ease of being able to tune the bike and not always wondering if you are lean or not. 2nd note. Turning the air screws in makes them richer. That site i posted up there helps explain how the carbs work and what needs to be done to help you tune them in. What mix ratio are you running? Also, why are you getting different carbs? Are they ones with a TORS kit on them? 1) more jets - aight i'll give Jeff a call and get some more on order. 2) Hrm I don't understand why running the screws out has any bearing on the bike running BETTER on the top end then.... There has to be some other issue that's causing problems (going to check for air leaks) 3) I'll re-look at the site 4) Gas - 32:1 Mix Ratio 5) Yes my carbs have TORS and the elbow that directs fuel into the left carb has had the grooves rounded off by someone else, I've been told I can't replace this part thus I found a set of carbs with the TORS removed. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.