I just finished cleaning, syncing (eyeball, but I'm pretty sure both butterfly valves are dead even) and jetting the carbs on a '04 GS. From completely stock and running, I went to a lunchbox filter and 20/62.5/140 jets. I know that a lunchbox and stock exhaust is sketchy, but the bolts inside the stock airbox broke when I took it off.
Here is my problem:
Bike has difficulty starting w/o full choke and a little bit of throttle finesse to get it > 500rpm. Idle with choke is shaky at ~1300rpm and if I give it some more throttle it will hover at about 3500rpm until I let the choke off. Once I do that, the bike will stall or idle roughly at 1100rpm before stalling. Turning up the choke again at that point does nothing - the engine will still stay at 1100rpm and eventually die. If I give it a good amount of throttle, it will go up to ~7000rpm and then stall completely. All over the band, there are varying amounts of vibration. Also I get the occaisional misfire that causes RPM to droop briefly.
-I checked the petcock/fuelhoses/bowls, etc. Nothing is pinched or on the wrong setting.
-I tried spraying some carb cleaner around the filter>carb and carb>engine boots, and nothing happened. I did accidentally spray a bit on the filter and the engine died.
-Checked the plugs, they are black, but not terribly fouled. They were like this BEFORE I took the bike apart. I'm probably going to pick up some new ones if nothing else occurs to me.
-the idle air screws are tightened on each bowl. Any less than tightened and they will quickly vibrate open, spilling gas.
Any suggestions? :icon_sad:
Quote-the idle air screws are tightened on each bowl. Any less than tightened and they will quickly vibrate open, spilling gas.
That doesn't sound right. Is there a spring and o-ring in there?
There isnt :/
Looking at the carb diagram on bikebandit, there doesn't appear to be any o-ring/washer.
We are talking No20 here not No31 right??? :icon_question:
http://www.bikebandit.com/showschematic/m9752sch510170 (http://www.bikebandit.com/showschematic/m9752sch510170)
31 is what I'm talking about.
31 should be tightened. This is to empty the bowl.
No21 is the mixture screw and as a starting point it should be set at about 3 turns out, from lightly seated.
No 40A is a plug that covers the screw and should be drilled if it's still on the carbs.
Also check the fuel level in the carbs. So the gurus :D have the full picture, as it will be easier to help you.
http://www.gstwin.com/float_height_check.htm (http://www.gstwin.com/float_height_check.htm)
^Ah yes, I did check the float height and it's fine. Sorry, forgot to mention that.
PS: the mixture screw is set at 3 turns.
Wow, you guys are not going to believe how retarded I am. I was putting my tools away when I noticed a pair of springs in the tool tray... :icon_eek:
Thats right - I FORGOT TO PUT THE NEEDLE SPRINGS IN!
Well lo' and behold: the powerband is fixed. Revs all the way up without issue (I'll need to see how it does on the road). The idle is still a little rough below 1500 and rpms don't drop as fas as I would like when I let go of the throttle, so it seems to be running a bit lean.
Quote from: jvitzu on September 07, 2009, 03:01:43 PM
Wow, you guys are not going to believe how retarded I am. I was putting my tools away when I noticed a pair of springs in the tool tray... :icon_eek:
Thats right - I FORGOT TO PUT THE NEEDLE SPRINGS IN!
Well lo' and behold: the powerband is fixed. Revs all the way up without issue (until I take it out). The idle is still a little rough below 1500 and rpms don't drop as fas as I would like when I let go of the throttle, so it seems to be running a bit lean.
LOL :D
I have done it too! LOL..
It was the needles fault I tell you, it did it on purpose!!! :D