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Discussion Starter · #1 ·
ok... I know people are tired of seeing "what jet size" etc. for carb mods but I am a bit stuck here and looking for some ideas

I am running my 01 with K&N, Yosh full race system, 17.5 pilots, 146 DJ mains and needles, and tank spacers. I had my SV running its best with a slipon, K&N, 17.5 pilots, 142 DJ mains and stock needles.

Long story short... I got a full Yosh system and added Flo-commander but removed the FC because I had problems getting it dialed in and lost a screw in it and went back to old carbs. I tried using just the DJ kit stuff (DJ main jets and needles) and just can't get it right. I had used the recommended 144 main and bike ran good up to 5 or 6k when power just dropped off and it revved slowly up to redline under load. So looked at plugs and seemed to be running lean (little white on tip and no gas smell out of exhaust or smoke)... went to 146 main and still same thing... runs good and almost pulls front up off idle up to 5 or 6k and then it climbs slowly to redline. No power up at top.

So I am wondering if I need to goto a DJ stage 2 kit because I don't have anything bigger than 146 in the stage 1. Also, wondering if it could be a problem with the floats... I never have checked their levels and never messed with them but they didn't seem to be sticking.

Any advice from carb tuners would be appreciated. ;)
 

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IMO the DJ kit is horribly specced- it was designed for use with the very first K&N, the one that was more restrictive than stock, and never revised. The stage 1&3 kit is no better, it goes up to (I think) 146 then jumps to 180. The instructions were of no use to me at all, since the filter they used as a baseline was so poor- with the Race RS you can't ride the bike with the setting provided, it's so lean above 6000rpm.

But don't worry, chances are all you need is some bigger jets, not a whole new kit. I just picked upa few bigger ones- 155 to 170 - and that sorted me out. I'm sitting a bit lean on 165s but to be honest I can't really be bothered to change up again :) So it'll wait till it finally goes to the dyno for proper setting up.

All ve much IMO! But you've not ridden a badly running SV till you've used the recommended specs for filter + system out of the DJ Stage 1&3 kit with a Race RS filter and decent system. Not many bikes slow down when you open the throttle...
 

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Discussion Starter · #3 ·
Northwind said:
IMO the DJ kit is horribly specced- it was designed for use with the very first K&N, the one that was more restrictive than stock, and never revised. The stage 1&3 kit is no better, it goes up to (I think) 146 then jumps to 180. The instructions were of no use to me at all, since the filter they used as a baseline was so poor- with the Race RS you can't ride the bike with the setting provided, it's so lean above 6000rpm.

But don't worry, chances are all you need is some bigger jets, not a whole new kit. I just picked upa few bigger ones- 155 to 170 - and that sorted me out. I'm sitting a bit lean on 165s but to be honest I can't really be bothered to change up again :) So it'll wait till it finally goes to the dyno for proper setting up.

All ve much IMO! But you've not ridden a badly running SV till you've used the recommended specs for filter + system out of the DJ Stage 1&3 kit with a Race RS filter and decent system. Not many bikes slow down when you open the throttle...
thanks for the advice... I might just look for some bigger mains then. Trouble is I will have to Mikuni jets probably because don't think I can get DJ jets seperately without kit... or at least I don't know where this is possible and I will have to do some thinking on what range in Mikuni jets would be good?? Maybe I should go back to stock needles again and use with Mikuni bigger mains.

I asked a DJ rep on phone what the deal was with their jet ratings compared with Mikuni and he told me they rated them in different regards and that theirs flowed more per size than Mikuni, but he didn't seem real keen on different setups because all he did was refer me to the documentation which shows a 144. Kinda makes sense but I still think there is something about the needles too. They are actually a tad smaller in diameter than stock (noticeable since the plastic spacer sits snug on stock but loosely on DJ needle) and I think maybe even lighter in weight (just seems so but never measured) so wonder what effect this has
 

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If your happy with the lower RPM set up...
Try a DJ 150 before you do anything else. I used that on my bike before... after I desnorkled the K&N the jets in the kit were useless. I bought some at a local speed shop... Im sure there is one in your area. I dont know what kind of fuel your using (like if it has any additives)...some people have had to use larger jets in that case.

I dout its the floats.
 

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with de-snorkled folter and stock exhaust I was running 150 main jets and it ran 100%. 
I suspect you're way lean.  I'd order 1 size each 148 through 160 and keep swapping them with the bigger one up front.  I'd suspect you need to be in the mid 150's.

With the 03 cam swap, full exhaust and BMC filter I'm now running 162 (can't remember if that's the bigger or smaller one though) :eek:

All jets are Mikuni's
 

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the best way to troubleshoot lean jetting is to put some duct tape over part of the air box. Try taping over ~1/4 - 1/3 of the intake. If this makes it run better then your jetting is off.
 

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Discussion Starter · #8 ·
yeah.... I tried the tape over the hole thing but all that did was make it bog down... though I am sure I am not running rich because exhaust doesn't smell like gas and doesn't smoke. The rear plug looked a little greyish too. I did notice that if I flip the choke... it did run just a tad better which again tells me I must be running lean. I think I am going to hunt some place on the net this weekend that will sell me DJ mains in pairs if they aren't too much and get a few in the 150+ range. If I can't find a place to do that... I am going to go to my local MC dealer and have them order me some Mikuni jets but they are about $5 each I think last I checked.

I guess I underestimated maybe how much more flow the full Yosh race pipe added over the slipon and the DJ stage 1 kit with its lack luster docs didn't help much. I think I just out grew the stage 1 kit and need to look for bigger mains. That may also explain why my Flo-commander setup didn't work as well as I hoped. I was running 144 mains with it. It ran better than it does now but I still lost some power on top end. Maybe I might try to get the FC going again once I get the main jet sorted out ;)
 
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