Gotta quit smoking

Discussion in 'The Garage' started by Bogfarth, Feb 8, 2013.

  1. Bogfarth

    Bogfarth Fridge Magnet Safety Tester

    Joined:
    Dec 26, 2011
    Oddometer:
    179
    Location:
    The Northwet
    Not me, the bike. It's a V-Star 650 Custom, 2001, with a V&H Cruzer exhaust (plus Smart Partz baffles wrapped in stove rope) and I've disconnected the AIS. Otherwise, there aren't any other mods. Until earlier this week, nary a puff came from the pipes.

    At idle I get a wisp of smoke from the front pipe, the same under power, and blows a large but faintly-colored blue cloud from both pipes when I roll off. It also pops once or twice almost like a backfire every now and then. The smoke shows up regardless of engine temp, and smells a little like gas. The bike starts on full choke, which I quickly reduce down to about half. I can ride at that choke setting until it warms up (a few minutes), then shut the choke and she'll go like a rabbit. There's about a gallon of two month old gas in the tank with a half can of Seafoam in it. I pulled the plugs and compared them to an online chart (here). They've got a little oil fouling, but nothing else. The plugs have less than 50 miles on 'em.

    So what have I done? In the past three weeks I've done some parking lot wobbling, shot Dri-Slide on the throttle cables, and today I cleaned the jets in both carbs. The pilot jets were just a touch gunked, while the mains were clear. Gas is a pale yellow, and has the usual reek of ethanol mix. The AIS has been disabled for quite a while, because it sounded like a popcorn machine every time I rolled off the throttle. Dri-Slide did drip from the carb face on to the front intake tappet cover. The intake boots are tight with no cracks, and the tappet O-rings are new. Either the Dri-Slide got inside the carb by running down the throttle shaft, or something else is going on...

    ... I just wish I knew what.
    #1
  2. yukonjon

    yukonjon Been here awhile

    Joined:
    Dec 20, 2011
    Oddometer:
    150
    Location:
    Pacific Northwet, Tacoma
    Wish I could help you since I'm also a vstar rider. Anytime I have a question I usually go to the 1100 v star forum. They are great on carb questions and generally everything specific to the 1100 and 650 vstars. Check them out if you want. http://forums.delphiforums.com/n/main.asp?webtag=yamaha1100&nav=start&prettyurl=/yamaha1100/start

    By chance did you adjust your PMS screws at all when you were playing with carbs. I know backing them out a quarter turn at a time will generally eliminate the backfiring on those bikes. Even with AIS removed.
    #2
  3. Bogfarth

    Bogfarth Fridge Magnet Safety Tester

    Joined:
    Dec 26, 2011
    Oddometer:
    179
    Location:
    The Northwet
    Oh, duh! I completely forgot about that board! :shog I'll copy-paste there momentarily.

    Nope, I haven't goofed around with the PMS screws. They still have the cover plugs in 'em, now that I think about it.
    #3
  4. yukonjon

    yukonjon Been here awhile

    Joined:
    Dec 20, 2011
    Oddometer:
    150
    Location:
    Pacific Northwet, Tacoma
    Any luck?
    #4
  5. willis 2000

    willis 2000 neo-quixote

    Joined:
    Oct 15, 2011
    Oddometer:
    3,937
    Location:
    idaho
    Adust your idle speed first. To do this properly, a synchronizing tool is required. Then, the idle mixture screws. Backfiring on decel tells something is out of adjustment, and it's considered lame.
    #5
  6. Bogfarth

    Bogfarth Fridge Magnet Safety Tester

    Joined:
    Dec 26, 2011
    Oddometer:
    179
    Location:
    The Northwet
    Shorely did! Thanks for checking in on me, and the reminder about the V-Star forum! Too much Seafoam + oldish gas = cigar smoke. Added a gallon of fresh and the smoke went away, plus it no longer pops. I'm always happy when it's the little stuff!


    Mine ticks over at 12-1300rpm, which is a tad fast of average. No tools needed, either; spin the thumb-wheel and the idle speed changes. I listened to a video of an M60 shooting before setting my idle speed. The exhaust sound is just a bit faster than the gun's firing rate, so I'm in the green. The backfire-like noise only happened when I blipped it or dropped the throttle after going WOT for a moment. With fresh(er) gas, that is no longer a factor. Thanks for the help, though!
    #6