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tuning carbs (video with smoke added)
Posted: Thu Jul 16, 2009 11:59 pm
by shredex
well as most of you know, Iv been having a richness issue and have been smoking out the exhaust.
some info
93' fzr600 motor
Factory pro jet kit (115 main jets/needle clip on leanest position) [107.5 mains is stock]
K&N drop in filter (fresh recharge)
R6 full exhaust
well, I couldnt get the bike to stop smoking even on the leanest settings,
So...I put the stock main jets back in (107.5) and it made the smoking WORSE...
it just puffed the smoke with any touch of the throttle. (still with leanest settings)
so I threw the 115's back on and just tried tuning it better with the A/F screws.
i first turned the screws all the way in. I had to turn up the idle like expected.
I reved it up and the bike took forever to come back down to idle after closing the throttle
I gradually turned the screws out till the revs stopped lagging to idle. I got it at a very nice smooth sounding idle. still smokes but it was the best I could get it.
then for kicks I backed the screws out 1.5 more turns to see what it would do. it had the same nice idle, maybe it was even better...but didnt seem right...
so I put it back.
the bike pulls noticably better throughout the rpms.
twice on the drive home the bike went down farther than idle when I stopped the bike...is this a lean or rich condition?
still, the bike kinda sounds kinda...idk...its like the difference between a blurry image and a really sharp image.
the sharp image is nice, clean, and crisp...where-as the blurry is...blurry?
and my bikes the blurry
Re: tuning carbs
Posted: Sat Jul 18, 2009 12:01 am
by shredex
ok.
I re-adjusted the mixture screws and apparently I had them at about 6.5 turns out!
so i put them back at the 3.5 I had them at
I talked to a guy that builds and tunes old muscle cars for a living.
he said to try a hotter plug.
I got a set of CR8Es and put them in and it did help the smoking a bit but it also did something to my powerband...I dont seem to have a powerband...its just steady pull throughout the throttle...I mean steady...no random burst of crazy at a certain RPM..just steady...but I did my wheelie test and it still does it the same so Im trying to find out if this steady thing is bad?
any ideas?
Re: tuning carbs
Posted: Sat Jul 18, 2009 12:50 am
by sweekster
A smooth and/or linear powerband is what you want..well without the smoke.
Re: tuning carbs
Posted: Sat Jul 18, 2009 11:11 pm
by shredex
i played with the carbs more.
it no longer has that really really nice smooth sounding idle, but it does pull a little better and still has that same pull power without powerband...
but when i start the bike after its been warmed, it doesnt really crank over that fast and I have to give it some throttlw because the idle is so low. but after leting it run for a min then it goes back to normal...im guessing this mean im running lean?
i mean like 150+ degrees warmed.
my bikes completly warmed up at about 120 degrees. i shut off choke at about 104 degrees.
Re: tuning carbs
Posted: Sat Jul 18, 2009 11:17 pm
by shredex
waiting to get the A/f right to sync...dont want to sync then mess with the A/F cus that effects syncing
Re: tuning carbs
Posted: Sun Jul 19, 2009 2:36 am
by match417
I don't know how the Factory Pro jet kit is, but when I put in my dynonet kit I had to enlarge the air holes in the diaphragms so they would float higher at idle. So IF I were to put stock jets back in then the diaphragms would float higher, and since the diaphragm slide location directly effects the height of the needle behind the main jet, I would guess that (if you're having problems with the jet kit in the carbs) either the wrong size bit was used on the slides, or the a/f ratio wasn't adjusted right after the jet kit was installed, and the bike isn't running right with the stock jets back in because the air holes in the slide are larger and it throws off the way they should be adjusted as stock carbs. Again, I don't know how the factory pro kits are installed. That would be what I look at first though, try to put the factory pro kit back and adjust the a/f ratio, if that doesn't work then I would try to see if factory pro could help you out at all, it wouldn't hurt to call them to see.
Re: tuning carbs
Posted: Sun Jul 19, 2009 2:44 am
by shredex
match! your alive!

.
i only put the stock main jets back in, but took them back out right away.
Factory pro kit doesnt require drilling. its a drop in kit.
I just need to learn about lean and rich symptoms more.
right now I have it set where I need to give it throttle to start even when its completly warmed up. when I start it the idle is very low but comes back up in a couple seconds after playing with the throttle. it never did that before...usually when I start it its at the idle I have it set at...now the idle is really low on start so much that it cant, but with a little throttle it starts up.
Re: tuning carbs
Posted: Sun Jul 19, 2009 4:45 am
by sweekster
Usually when you blip the throttle and it drops below idle and hangs down there before coming back up to idle it's lean. If it sits above idle before going back it's rich. You sure you don't have a blocked pilot jet or two? I ask because that was my problem. I'm currently at the 2nd clip from the top on my FP needles and my bike is pretty much there. I remember you saying you were at the top clip on your needles. Maybe go up one...
Re: tuning carbs
Posted: Sun Jul 19, 2009 1:24 pm
by shredex
its not when i blep the throttle...
its when I try starting it, I have to hold open throttle because the idle on start is so low that it wont catch, but after a few seconds it comes back up.
iv got no blocket jets...just pulled apart the carbs 2 days ago and managed to break one of the float bowl gaskets and now it leaks fuel very slightly >:C
Re: tuning carbs
Posted: Sun Jul 26, 2009 3:52 am
by dru86
sweekster wrote:Usually when you blip the throttle and it drops below idle and hangs down there before coming back up to idle it's lean. If it sits above idle before going back it's rich. You sure you don't have a blocked pilot jet or two? I ask because that was my problem. I'm currently at the 2nd clip from the top on my FP needles and my bike is pretty much there. I remember you saying you were at the top clip on your needles. Maybe go up one...
Other way around, If it hangs up it's lean, if it drops below idle it's rich.
Re: tuning carbs
Posted: Sun Jul 26, 2009 12:54 pm
by sweekster
dru86 wrote:
Other way around, If it hangs up it's lean, if it drops below idle it's rich.

I have to agree...things make more sense now...
Re: tuning carbs
Posted: Mon Jul 27, 2009 10:51 am
by shredex
Re: tuning carbs
Posted: Mon Jul 27, 2009 3:15 pm
by Huckleberry
wtf ?...... are ur gauges upside down?

btw have u checked compression and did a leakdown test?
Re: tuning carbs
Posted: Mon Jul 27, 2009 3:51 pm
by reelrazor
Rings.
Re: tuning carbs
Posted: Mon Jul 27, 2009 8:46 pm
by Huckleberry
reelrazor wrote:Rings.
thats wut i'm thinkin 2