goldwing six runs rough, but carbs rebuilt

Discussion in 'Motorbike Technical Discussion' started by bill yohler, Jul 18, 2003.

  1. bill yohler

    bill yohler Guest

    My goldwing six, GL1500, has two carbs, both of which I recently
    painstakingly rebuilt, but NOW I have some bizarre problem, seemingly
    carb-related <but maybe not?>:

    it starts up just fine when cold or hot, but it runs lousy, with cold
    OR warm engine. When it's cold, just after starting, even with the
    choke all the way ‘on', when I twist the grip, even SUPER-slowly, it
    dies -immediately-. This is ‘still on the centerstand' here, I mean.
    When it's warmed up, still on the centerstand, it seems more like
    normal behavior, twist-grip-response-wise, but _only_ after the temp
    gauge is halfway up or more...

    by the way, took painstaking notes _and_ made drawing when dismantling
    carbs, so chances I put some jet or tiny hose 'back in the wrong
    place' are ZERO.

    The main problem is, when it's on the centerstand and I have the
    throttle lock 'on' (_or_ when I try driving any ‘set fixed speed' down
    the hiway), it WON'T maintain a steady RPM setting, on the centerstand
    OR the road.. Also, when starting up from ‘stone cold', with the choke
    even ‘full on', it flat out "dies stone dead immediately" when I twist
    the throttle, even when I twist it super-SUPER-slowly. And I mean
    _dead_crawl_ slowly here, too...before the carb overhaul, it was at
    _least_ ‘driveable' cold, with the choke, it's nowhere NEAR
    driveable, cold, not even CLOSE....

    When it's warmed up, though, and I try driving down the hiway, it runs
    up smoothly ‘thru the gears', just as strongly as it ever did, even up
    to 5000 RPM in 1st, 2nd, 3rd, and 4th, but when I try setting the
    throttle lock, on a long flat road (say in third or fourth, attempting
    a 2000, or 2500 or 3000 RPM steady cruise), it won't do it, or even do
    anything ‘close' to it - instead, it acts as if someone shuts the key
    OFF every three or four seconds out of five or so, roughly. Like it
    ‘just ran out of gas' every few seconds. frustrating. On the
    centerstand with the throttle lock on, at ‘locked ranges' in the like
    2000 to 3000 RPM areas, it ‘varies up and down' every few seconds,
    too, dropping 500 RPM one second and speeding up 6 or 700 RPM a few
    seconds later, and on and on, minute after minute, same deal, from the
    same locked twist-grip setting (and the throttle lock works
    fine)...this is driving me NUTS. I know it's some ‘simple thing', but
    the " which simple thing is it?" bit is the main there
    _any_ possibility this is 'ignition related'? my guess is carbs, but
    not sure, at this point...

    The faster I try to go, in the higher gears, the worse it seems to
    get. It's not ‘breaking up', though; it's more like acting ‘fuel
    starved' or something. BTW, the air cleaner has JUST been cleaned, and
    the fuel filter is nowhere -near- being clogged, and today I tested
    the fuel pump output against factory ‘minimum specs' for delivery per
    minute and it near -doubles- that output....also, when I took off the
    fuel hose TO the carbs today, about 20 minutes -after- my last road
    test, there was -still- plenty of fuel pressure IN the fuel line, if
    that indicates anything.

    and, all six spark plugs were recently sandblasted lightly and gapped
    correctly. It idles just fine (after warmup). also, when the carbs
    were dismantled, the floats seemed to work fine, not sticking, and
    float levels are adjusted correctly in both carbs (used dial caliper).
    I don't own one of the special honda pilot screw wrenches (and tried
    everything else to get ‘em out; the heads on ‘em are ‘round with ONE
    flat side' plus they sit down inside a walled recess, so there's
    nothing to grip...) so I had to leave those two ‘in' (1 per carb) when
    I dismantled, soaked and later ‘blew out'all the carb passages, etc.
    the gasoline in it is only 3 wks or so old...

    got any ideas on this? How come when I ‘accelerate like a bat outta'
    hell' or 'just sit there idling' it runs great, but when I try
    ‘cruising' any set speed with a fixed throttle, it flat-out dies every
    other second or two....the faster I'm going down the hiway, attempting
    a steady cruise, the more time the 'on-off nuisance' factor seems to
    'elect' to stay in the 'off' election it so favors. I'd sure -like- to
    hear from you carb experts regarding your ‘most likely culprits list'
    especially those factors 'easiest to check out' first.


    bill, aka "mr non-steady cruiser"
    bill yohler, Jul 18, 2003
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  2. bill yohler

    bill yohler Guest

    today I bought and used yamaha carburetor cleaner (I found wild raves
    about it all over the net) at the local honda/yamaha dealer. It's some
    kind of ‘magic juice' you put direct into the float bowls ‘rather
    than' re-remove and re-rebuild your carbs :-\. I gave it a ‘sniff
    check' and it wasn't noxious or ‘powerful smelling' at ALL...

    so, I used it 'straight', instead of cutting it three parts gas to 1
    part cleaner like the carb cleaner bottle recommended. it made a
    slight_improvement in the jerkiness of the ‘fixed' throttle settings,
    but maybe it was 'wishful thinking' on my part. anyway, first I
    drained all the gas from both carbs; I got about an ounce from each
    float bowl. then I 'ran the stuff into' the carbs using a tiny funnel.
    then I let it 'cook' in the carbs for an hour/drained it out, and
    refilled both float bowls with gas, _trying_ to 'pump the gas into'
    the carbs with the fuel pump. I even ‘topped up' the half-full tank
    with 89 octane, fresh, before todays late day road test, to no avail.

    But during todays carb-related festivities, I discovered

    1. My fuel pump does NOT "come on" when I turn the key on (I used a
    stethoscope touching the tank itself when I turned the key-I wanted to
    make DANG sure I could hear ir run over the ambient street noises).
    But it didn't run, key on. so I says "ok, maybe I need to put the kill
    switch back into 'run' instead of 'kill', but still no dice. Bike in
    neutral/no dice. note, when I 'tested' the fuel pump a few days back,
    I "hot wired it direct' from the battery with 2 small jumper
    leads/alligator clips. so now I'm thinking, "sheesh, maybe this really
    _is_ a fuel starvation problem and not a carb problem".

    do you KNOW if the GL1500 fuel pump is supposed to be running
    continously whenever the key is 'on'? or is there some 'fuel level
    sender' or other gizmo somewhere else on the bike (seems doubtful to
    me) that sends 'hot power lead flashes' to the pump when fuel is
    'sensed' to be needed? most -electric-_fuel pumps (in cars) run
    continously, right? do ya know for -certain- wether or not it should
    'run' when the key is 'on'? I figured, after draining out the carb
    cleaner, and trying to ‘pump gas into' the carb electrically, with the
    key ‘on', that this is a ‘known low float level in BOTH bowls with
    zero residual pressure in the post-fuel-pump fuel line' type
    situation, so, if the fuel pump should EVER come on with the key, NOW
    would be that time, buddy-boy".

    But it didn't come on, kill switch on OR off. And I'm not at all sure
    -when- the dang thing really DOES run, electrically, when fed power
    thru my harness...what ‘dictates' when the fuel pump should be running
    or not? The bike brain? So, if mine's nor running at the ‘right'
    times, uhh, maybe I have "brain damage" (other than the obvious, that
    is ;-) <???>

    really, though, maybe my fuel pump has either a intermittent ground
    (fuel pump to tank, or tank to frame) OR the harness 'power lead' to
    the pump itself is 'intermittent' instead of continous...or is there
    some ‘fuel pump hot lead activator' on the bike somewhere? Or maybe
    the ‘brain' won't let the pump pump UNTIL the engine actually DOES
    start? <???> that make any sense?

    I'm thinking of running a temporary small ground wire from fuel pump
    stud to known good ground. If THAT doesn't cure the ‘herky-jerky'
    cruise krap, maybe I'll hook a tiny LED in circuit with the fuel pump
    and place the LED taped to the dash/drive it down the hiway/see just
    "how" the starvation behavior seems to jive with the tiny led being
    'on' or off...maybe tomorrow I should also see if the pump comes ‘on'
    when I jump it direct from the battery EVERY time, every other second
    or so, for sixty or eighty attempts in a row, or wether it just comes
    on ‘when it feels like it'... about half the times it should be ‘on'
    and running, roughly..

    Well, these are the mysteries that plague me soul... ;-) one thing fer
    sure: can't ride it like it is now...
    bill yohler, Jul 19, 2003
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