I did read the stalling & cutting out section in the H.O.W. and found it very helpful. I assume, I have "dirty" carbs, since I found the tanish / white "sheet-rock-stuff" in the intakes and carbs. Problem: 1. Engine started popping when decellerating 2. Engine dies sometimes, when sitting at idle speed at a stop light 3. Engnine idle speed sometimes varies between 1,400 and 1,700 rpm Stats.: ’06 950 Adv<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o> <o></o> Odo:2,600 miles<o></o> <o></o> Fuel consumption: 36-38 miles/gal. <o></o> <o></o> Work done:<o></o> - Canisterectory (carbs vented outside airbox, 2" below airbox, no filter)<o></o> - SAS removal<o></o> - TB for connecting left and right fuel tank for venting. - Tank vented individually straight down. <o></o> I have not messed with any carb settings at all, since it run nicely as it came from the dealer. Also, I just completed a 500+ mile trip, half of it interstate. I noticed the problem creeping up the last 50 miles of the trip. Acceleration through 8,000+ rpm is flawless. Just looking for confirmation / other pointers. Thanx y'all <!-- / message --><!-- sig -->
I'm not sure what you mean by the "sheet rock stuff" - you actually have dirty deposits in the carburetor intakes? That notwithstanding, the other symptoms could indicate an air leak at carbs or intake manifolds. Check where the vacuum feed to the SAS etc has been blanked off for example.
+1 on what UK_Mouse said, "check the vacuum port caps". the nipples that thread into the side of the intakes should be replaced with m6x10, 1.0 pitch allen drive screws. the other thing that I would suggest is draining the float bowls, but the reality is that you almost have to remove the carbs to get to the drain screws so you might as well pop them up and out so that you can open them up and clean them properly. as far as the white dust/powder. this should only be present INSIDE the float bowls or posibly a small amount in the inner throat of the carbs down near the slides or butter flies. if the intake bells are dusty then the air filter is not, or the seals are not working. if you have been riding major dusty enviros with other bikes where you are sucking truck loads of air bourne dirt make sure your stock filter is not completely plugged and pulling air past the seals or other places that might be leaking. the UNI prefilter pretty much eliminates the dirty primary filter problem and is washable. it also, with proper jetting, will transform how the engine runs at lower/mid RPMs. (I have the jets if you decide to UNI-prefilter it)
Thanx for chiming in guys ! Let me combine the answers to your responses here: - I used the "sheet rock stuff" terminoligy from the H.O.W. just to be consistent with what has been used describing the whitish powder like residue. While at the subject, this "stuff" is only at the inner throat of the carbs and intakes, i.e. its not from dusty environment. - When I did the canisterectomy, I did use M6x10 allen head screws/gaskets at the intakes. I did check the connection hoses and plugs I use for carb synchronizing, no leaks. - I did the valve adjustments at 800 miles and they are on the loose side, but within the tolerance. Now, my experience with "high tech" carbs is limited. I'm used to the midevel versions from the '70 and '80 bikes.... So, I'm somewhat challanged with diagnosis and isoltating problems on these puppies. But, if I understand correctly (and here is were y'all come in...) if the inconsistencies only show up at idle rpm, wouldn't it be logical that maybe the idle jet and/or ACV jet are constricted, i.e. leaner air/fuel mixture, therefore popping at deceleration... The same might be the reason for a fluctuating idle rpm range of 200-300 rpm (air/fuel mixture gets lean = rpm goes up...) Then there is the occasional stalling when sitting at a stop light at idle... As soon as roll the throttle on, even rapidly, the bike goes flying without choking etc. ...so, how far off am I? Thanx
I experienced similar symptoms. No whitish residue, but plenty oil misting around the front carb from the case breather. I suspected that a drop of oil had clogged a jet or passage, so I yanked the carbe and cleaned it and blew it out. All better. Note that at 2,600 miles, the engine still feels pretty tight -- IIRC, mine was pretty sensitive and prone to dying from idle until things ran in. A 3,000-mile road trip did the trick.
Hey guys, thanx for the feedback! I will go with some carb-cleaner first, to see if I can rid the carbs of any obstructions before tearing into it...
thanks for the info, I'm having similar probs. My bike would idle low with full choke on until it warmed up, then would run higher RPM's with full choke on. AND I have popping on decel.... i'll pull the carbs and see what i see.
Besure your battery terminals are tight and making good contact, also check the ground wire where it attaches to the frame. Or it could be some bad gas, drain and fill with known good gas. Look for the simple solutions first.
Oh man, I feel like an idiot ! I was about to tear into the carbs and do some cleaning, when I made the grand discovery... Some of you had already suggested an air-/vacuum leak, which I had checked and verified. In the process, I also checked the carb sync hoses at each end for leaks. But, I didn't check the "middle" of the hoses. What had happened, one hose had wiggled loose and got in conact with the headder pipe, burning a leak into one hose...voila, problem solved! Again, thanx everybody!
