Seems like it's problem after problem with this bike. Oh, well. It's a good thing I like working on it almost as much as riding it. Anyways, I'm pretty sure I have a vacuum leak now. I just did a rejet, so now my setup consists of a lunchbox, stock exhaust, 140 mains, 40 pilots, dynojet needle on clip #2 (stupid PO and their stupid DJ kit) :mad:, and 3 turns out. When I did the rejet, I noticed that one of the diaphrams where the needle drops into was pinched slightly when I took it off. I don't think there was a tear or anything in that, but there might be now. So onto my symptoms. Bike doesn't start fine (think that's due to a bad battery, i've been push starting it the last couple days, once it's warm, the starter will work just fine though), mostly everything is fine while it's warming up and for about 5 minutes until it gets warm (used to take about 20 minutes with old jets), then once it's warm, the idle goes high, like around 4-5k rpms and stays there (and yes this is with the choke off by this time). On my way to work this morning, I had to have it in first at all stops and let the clutch out some so it would come back down to a normal level. I'm pretty sure it's a vacuum leak, I really doubt that I'm lean still, and my throttle cable has slack. I'm more or less just wanting to know the possible places for a vacuum leak. Where should I check and if it's not there, where else? I guess it could be that diaphram that was pinched, but I'd like to check the gaskets to the carbs and things like that before I tear off the tank again. Thanks for all your insight!
I just got home on lunch, and sprayed WD-40 all over the carb boots while it was running, and absolutly nothing changed. I was about to give up, so I blipped the throttle to see what it would do, and it went up to 4.5k rpm and stayed there. I have a theory, so someone please tell me if I'm way off base...
The Dynojet needle has an odd taper, plus it's smaller at the bottom than the stock needle. The stock comparison jet for the Dynojet package is a 118 main, so I'm thinking that the small needle going into the 140 main isn't sealing completely when the throttle is closed and it's still reving up along with the pilot jet.
Other theory that I still haven't checked is the diaphram to see if there is a rip in it. Where else could there be a leak?
Now that I think about it, I did have this happen before, but it was only after a 20-25 minute ride, when the bike got totally warmed up. I guess now with it warming up faster, it would be the same relative time. So maybe it has nothing to do with the new jets. It's got to be a vacuum leak. Unless the Dynojet needle is to blame somehow. A vacuum leak and the DJ needle are the only things that would be the same from then till now.
Anyways, just writting my thoughts as I go. Anyone have similar problems with a solution?
did you see if the o ringis missing under the balck cap on the top of the carbs :dunno_white:
I couldn't say for sure, but I'm pretty sure I made certain they were there. If I end up opening them up to check the diaphram, I'll check those too.
Just found this link
http://gstwins.com/gsboard/index.php?topic=33859.0
I'm wondering if that might be an issue. I removed all the smog crap, so maybe something got loose, or something didn't get plugged, or maybe I'm having the same problem he is with those things being loose.
That post sounds like as good a clue as any ... certainly worth checking out!
Quote from: quiktaco on November 07, 2007, 03:54:13 PM
Just found this link
http://gstwins.com/gsboard/index.php?topic=33859.0
I'm wondering if that might be an issue. I removed all the smog crap, so maybe something got loose, or something didn't get plugged, or maybe I'm having the same problem he is with those things being loose.
that i don't know about mine doen't have that on it .......also check the boots between the carbs and the air box ,that they are fully seated ,i had isues when i was doing my carbs
Did you make sure to set the idle when the bike was fully warmed? I had the same problem until I set the idle properly. When you get the idle jumping problem, try turning the idle screw to lower it back down to ~1200 rpm.
Good luck!
Think I may have fixed it. While warm everything is fine now with the idle screw adjusted. Couldn't find an air leak earlier, so hopefully this is all it was. I turned it way down, then back up to around 1400 rpm. Hopefully it isn't too low when it's cold though...that's the problem i've been having, because it won't start and stay started being set this low
Quote from: quiktaco on November 07, 2007, 07:43:02 PM
While warm everything is fine now with the idle screw adjusted. [...] I turned it way down, then back up to around 1400 rpm. Hopefully it isn't too low when it's cold though...that's the problem i've been having, because it won't start and stay started being set this low
It pays to get good at adjusting the idle screw while you're riding (or stopped at an intersection). When the weather gets cold, my bike loves to die at the stop sign a couple blocks from my house. (That is, it
would if I didn't still have my choke on that point. :icon_rolleyes:)
Seriously, I have never arrived at a "one-size-fits-all" position for the idle screw. Inevitably, I'll pull up at an intersection at SOME point during a ride around town and find that my idle is either too high or too low. No problem ... I just reach down and give the knob a quick turn while I'm waiting for the light to change.
This weekend I was fiddling with the idle mixture scew after I thought I had warmed by bike up enough, I quickly jumped on the hwy no choke at that point, got off at the next exit and sure enough the idle adjustment was way too high, really high. I quickly lowered it and got the bike back down to 1200 rpm. I had to make a mental note not to raise that screw too much. I understand what you said about the bike seeming to have a lot of problems, but really just think of it like a lot of easy little problems to fix, then it wont seem too overwhelming. :thumb: :thumb: