gomerkfx700 Posted March 16, 2014 Report Share Posted March 16, 2014 ok i have had this bike for 2+ years building and working on it got motor together last year and got it started. then our baby that had been in the hospital got to come home and it wasn't touched till today now she is healthy and daddy needs his banshee fix. ok first off i rode it one time last year just up the road and it was like hitting a wall at mid throttle so i figured ok its rich. so fast forward a year or so and today i took the carbs off the shelf cleaned them up jetting is 27.5 pilots 320 mains mid on needle. i went down to the 320 from 340 last year. and same thing i messed with needle and went to 300 main same thing messed with needle 300 main same thing. idles nice seems to dry rev ok when setting in neutral. the engine is 421 serval pump gas cpi inflames stock carbs. the cdi and all electronics came from a running bike but i did drag cut the wiring harness as seen on this site. i think the timing is at 2 or 3 degrees have to take the side cover off its been close to 2 years since i put it together. could it be the timing to much bad flywheel bad cdi or something like that. i told the wife im fixing it or selling it she went off telling me im not selling it i have done spent to much money on it so fixing it it is. Quote Link to comment Share on other sites More sharing options...
Buckwheat Posted March 16, 2014 Report Share Posted March 16, 2014 Air filter in good shape? Quote Link to comment Share on other sites More sharing options...
gomerkfx700 Posted March 16, 2014 Author Report Share Posted March 16, 2014 still have air box and new k/n in it. also has vf3 with reed stuffers peddles look ok but i wouldn't think that the reeds would cause it to do this i could be wrong. Quote Link to comment Share on other sites More sharing options...
uman1030 Posted March 16, 2014 Report Share Posted March 16, 2014 Assuming you've done a leakdown test to rule out an air leak causing a lean condition? Jetting sounds very conservative for a 421 serval. Alot of people run those jets on stock motors with some pipes and pods. Quote Link to comment Share on other sites More sharing options...
gomerkfx700 Posted March 16, 2014 Author Report Share Posted March 16, 2014 i was told by andy at no limits that 340 should be a rich starting point and should have to go down from there. i thought the same thing but he said that the signal threw the carbs are greatly amplified by the small carbs on such a large engine it will pull more fuel threw the carbs then a much smaller engine can. so i put in what i was told by him. i would call him but he is closed today and i think tomorrow. and no i haven't done a leak down i don't have the stuff to build a tester. Quote Link to comment Share on other sites More sharing options...
uman1030 Posted March 16, 2014 Report Share Posted March 16, 2014 If thats the advice he gave you then i would assume he knows what hes talking about. If lowering the main jet size had no noticable improvement i would probably go back to the larger size for safety measures and look in other directions such as A/F screw settings and possible spark problems. Quote Link to comment Share on other sites More sharing options...
lil Doobie420 Posted March 16, 2014 Report Share Posted March 16, 2014 Where is grundy I'm in va also. Quote Link to comment Share on other sites More sharing options...
gomerkfx700 Posted March 16, 2014 Author Report Share Posted March 16, 2014 Where is grundy I'm in va also. other end of the state from you its were ky, va, and wv all come together. Quote Link to comment Share on other sites More sharing options...
gomerkfx700 Posted March 16, 2014 Author Report Share Posted March 16, 2014 If thats the advice he gave you then i would assume he knows what hes talking about. If lowering the main jet size had no noticable improvement i would probably go back to the larger size for safety measures and look in other directions such as A/F screw settings and possible spark problems. air screw has no affect with the 340's tried 25 pilots it won't hardly start with them at all at 2.5 turns out 27.5's at 1.75 turns seems a little fat idling but got was getting angry because of the rev issue and thats when i said screw it. Quote Link to comment Share on other sites More sharing options...
lil Doobie420 Posted March 16, 2014 Report Share Posted March 16, 2014 Ahhh u should try to make it to busco for the eastcoast ride. Sorry for thread jacking Also soundes lik u need more fule. Ride is the weekend after mothers day Quote Link to comment Share on other sites More sharing options...
gomerkfx700 Posted March 16, 2014 Author Report Share Posted March 16, 2014 im going to try more fuel soon as i find my other jets i have up to 370s just have miss placed them. Quote Link to comment Share on other sites More sharing options...
monster Posted March 16, 2014 Report Share Posted March 16, 2014 (edited) Mid rang is controlled by the needle. On my 10 mil serval had to get new needles to lean it out in the mid. Carbs ran great with my 4 mil been playing with the jetting for weeks trying to get it perfect on my serval here's a link that helped me. http://www.smellofdeath.com/lloydy/jetting.htm Edited March 16, 2014 by monster Quote Link to comment Share on other sites More sharing options...
FullThrottle_06' Posted March 16, 2014 Report Share Posted March 16, 2014 Gomer, are you running the stock needles? I had problem's with the stock needles when I was running my stock stroke/stock cyl, setup w/ pods. Switched to the dyna jet needles and fixed my problem. The dyna jet "kit" is a waist of money and I wouldn't suggest buying it but the needles offered in that kit fixed my problem and I was running a setup with a lot less HP than your serval. Quote Link to comment Share on other sites More sharing options...
gomerkfx700 Posted March 16, 2014 Author Report Share Posted March 16, 2014 im not sure if its the stock needles or not whats the numbers on them and ill look and see i am considering just buying a set of carbs and a intake probably 33 or 35mm pwk Quote Link to comment Share on other sites More sharing options...
sstaton1983 Posted March 16, 2014 Report Share Posted March 16, 2014 A Plug chop will tell you if you need more fuel or not, I bet their lean and dry. 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.