turbowrenchhead Posted March 16, 2013 Report Share Posted March 16, 2013 I have a chance to do some WOT throttle runs and do a plug chop in two weeks. Right now I have a 2-1 on it with a 35pwk with 60 pilot 170 main and a EEK needle on the leanest clip. I rode it for one hour out on the lake and all it did was spin when it hit the power band. I pulled the head when my clutch basket blew up and took a pic of the piston tops. One cylinder looks great but the other one is too rich. I am going to get the dual carbs setup and try to tune them separately. I looked through a old post jet form on what everyone runs for pilot's and mains. I wrote down a bunch and tried to come up with a good starting point. Pilots range from 25-42. Mains from 290-380 One machine that was similar in mods and sea level was running a 27.5 pilots and 380 mains. That seems huge to me. However there wasn't a line for needle size. I believe that mikuni rates their needle's differently and I'm not familiar with those yet. I have only worked with Keihin's so far. I would like to know what is a stock needle size and what would be richer? I'm trying to gather up a good needle and main selection before I go to tune. I don't get the opportunity often so I must make good use of the time. I have a trip planned with the guys in May in upper Wisconsin. They are not going to stick around and wait for me to tune up my machine. I'd like to have it ready to rip when I get there. Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 16, 2013 Author Report Share Posted March 16, 2013 I meant to say EEG needle. The sig is current. Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 16, 2013 Author Report Share Posted March 16, 2013 This is a pic of my rough cut on my port job. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted March 17, 2013 Report Share Posted March 17, 2013 what temp there? and elevation? I run a stock stroke, play/dune port by jeff, FMF pipes, VF2 reeds, +4 timing, 20cc domes 156psi, K&n pods........my bike was jetted for 70* and at 1100' and I was at a 27.5 pilot and a 320 main.......stock needle middle clip Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted March 17, 2013 Report Share Posted March 17, 2013 Just a side note for future DIY porting. You need to aim that boost port much steeper. Unfortunately , the bottom of it has already bee cut too low. Something you can change next time. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted March 17, 2013 Report Share Posted March 17, 2013 Unported 4mil, K&N, FMF Signature series, Vito's reeds. 310-320 depending on temp, 27.5 P, @1 1/2 A.S., middle clip. Little rich but safe. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted March 17, 2013 Report Share Posted March 17, 2013 Same elev as Jereme, same riding spots, even same neighborhood Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 17, 2013 Author Report Share Posted March 17, 2013 Just a side note for future DIY porting. You need to aim that boost port much steeper. Unfortunately , the bottom of it has already bee cut too low. Something you can change next time. So you want it to aim more towards the top of the combustion chamber? Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 17, 2013 Author Report Share Posted March 17, 2013 So it looks like I don't have to worry about pilots or needles. I just have to get my hands on some mains Any suggestions on whom to buy from? Are they ok off of ebay? Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted March 17, 2013 Report Share Posted March 17, 2013 you can order them from just about any of our site sponsors.........however.....if its mikuni that your runnin......take it up to a snowmobile shop. The mikuni carbs all run the same mains (from what I was told by the snowmobile shop) and they have PLENTY in stock. Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 17, 2013 Author Report Share Posted March 17, 2013 Probably a good place to go to get cheap mains. I'm looking at $5 each on ebay and if I want to get a range its gonna cost enough. Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 19, 2013 Author Report Share Posted March 19, 2013 I called a few sled shops today. One place said they would sell used mains for $2 a pop. Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 20, 2013 Author Report Share Posted March 20, 2013 I called around to several snowmobile shops in my area. I found a deal $2 each on mikuni main jets so now I have a set of 320,330,350,360,370,380 and 390. They didn't have 340's. Now does mikuni make sizes in between the 10's? Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 26, 2013 Author Report Share Posted March 26, 2013 After several tries with 370's & 360's and couple different clip positions I now have 330 main's. 25 pilots needle on middle clip. No backfire now like when I had a 320 main on the RH cylinder and 330 on the LH. Did a street run up to 3rd gear. The power band is much more smooth then the single carb. It still flutters at WOT. Its hard to tell if its rich or lean at WOT. I would have to guess a tad rich. I won't know untill I can do some WOT runs up to sixth and plug chop it. However I already like the way the dual's feel versus the single carb. 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.