CV carb problem-Update

[harleytoprock]

Rode 5 miles to meets some buddies. Bike is running awesome! Shut down bike for 10 minutes for some BS talk. Fired it up to go and now when I roll on the throttle,  the fire goes out. It would come back at an idle. Thought I forgot to turn on petcock but its on. It would run with the choke on but would bog out when put back in. I nurse it back home. I've checked some things but can't really find anything wrong. Here's what I checked:
Removed the float bowl, its full of gas, no water, some dirt speckles but not much. Main jet and slow jet are clear. Carb vent is clear. Tank vent is clear.
Turn on petcock, gas flows good with float hanging down and shuts off when I lift the float. Slide seems normal when I lift it with my finger and drops down.
Could a manifold leak cause this? The fact that it idles, leaves me to believe that its not a manifold leak. I'm stumped. Got any ideas? Thanks

[Jeffd]

have you done anything recent to the bike prior to your 5 mile ride?

[ridemyEVO]

Is it firing on both cylinders? How much gas in the tank ?Maybe you got some crappy gas.

[smoserx1]

Check the slide diaphragm.

[tbird]

Check the intake manifold seals.   My experience has been if you can make it run by pulling out the choke, your running lean, usually the seals. "No fair-your suckin air"

[Velocity1]

I'm assuming youre petcock is aftermarket, (ie no vac required to allow gas to flow?)  Is the vac port on the carb plugged with a rubber cap?  One good backfire when starting motor will blow the rubber cap off allowing the vac. nipple to suck in fresh air.  I always install the cap and zip tie it below the bulb to ensure it can't come off. 

In line filter?  You noted dirt in the bowl.  I don't even run the fuel line to the carb after a rebuild unless I install a high quality in line filter.  Gas quality, (contaminants), has really gotten bad.  Everything from black flecks like pepper to sandy material golden brown, green and red.

How many times have you ridden this season?  Are you running last season's gas?  Here in the Northeast the ethanol in the gas has wreaked havoc in everything with a carb. where moisture had mixed with this gas from condensation.  The gas / water mix turns into a brown jelly like substance.  Ethanol also seems to swell and harden the rubber tipped needles causing leaky seating and needles hanging up.

If you suspect water in the gas, drain a cup or so in a clear glass jar, or enough for the petcock to to drain from the lowest level of fuel in the tank and let the gas settle.  See if you see any water in the bottom.  If so, completely drain the tank.  Add dry gas and refill with fresh gas and start over.

My recent experience early this season has been that I've seen this contamination / jelled gas problem in everything with a carb. from weed eaters to outboard motors.  In most cases disassembly on the bench and complete flushing with high grade carb cleaner and replacement of needle and seat resolved the issue. 

A high grade in line filter and good water free source of gas is key to keeping the fuel system trouble free.

Hope this helps.

V1 

[harleytoprock]

Thanks guys for the replies.
I'm still stumped. No jello found in the carb. Slide rubber looks good with no rips or holes. I put 250 miles on it a week ago Sunday with no problems. Filled the tank on the last 30 miles coming home with no problems with the gas. I really don't think its a manifold leak as it idled fine. Just bogs out when you twist the throttle. Feels like when you run out of gas. It would only run with choke on at faster speeds.I did change to a pingal petcock about 1000 miles ago. I wonder if something is stripped or slipping inside not allowing the gas to flow but only sometimes. Right now the gas comes pouring out of the hose when the petcock is on. Maybe I should turn it on and off about 20 times and see if its consistent. Maybe I should change the needle and seat to play it safe as there is 25k miles on the rubber tip. I just dunno.

[crazybastid83]

accelerator pump diaphram

[martida01]

Sounds to me like you know your way around the carb.  My vote is the intake manifold leaking.  Have you tried spraying around the manifold with carb cleaner?

[Evo160K]

Ride bike 5 miles, bike running awesome, turn bike off for 10 minutes, start bike, bike has problem.  Would hate to think those buddies would mess with your head?  Plugs and wires ok?

[86fxwg]

May not be your problem ,but i junked my pingle.The plastic seal was turning and shutting fuel off (just letting fuel drip)evey coulpe of starts and stops i had a hell of a time finding the problem.Im betting on the accelerator pump.Food for thought.

[harleytoprock]

My buddies are smart enough not to mess with my bike and not smart enough to know what to mess up.
Besides my bike never left my sight, nobody was near it.
I haven't checked the accel pump yet. I'll check it tomorrow.
I have to check the pingal again. Maybe something with that. Thanks again!

[Admiral Akbar]

Did you pull the slide when you checked the diaphragm?. Did you check slide movement? Hole in the bottom of the slide plugged?   Did the clip or hat come off the needle?  No one dumped any diesel in the tank? Max

[Mix01FLHT]

What year and model bike is it?     Might be barking up the wrong tree.  When my 00" dyna did the same thing, found out it was the battery.   Not even close to the carb.

[ICANTD55]

It idles OK but bogs when throttle is snaped open.
How about you pull the A/C and look at the slide movement when you give it throttle.{ bike running, edit} See if the slide is going up along with the needle. Open throttle slowly and see what happen. This will keep the acc pump at a min and see if it still boges. Then snap it open and watch the pump nozzel.
Did the air fuel ratio screw fall out or back out?

[Admiral Akbar]

Not even close to the carb.

This wouldn't surprise me in the least.. When trying to diagnose running problems between carb and lectric, I'm only batting about 300...   Max

edit carb and lectric..

[Sonny S.]

I would think if the throttle was snaped open, and the slide went up, it would sneeze through the carb if it wasn't getting fuel. The bog, almost sounds like the slide isn't rising properly ......bwtfdik

checking the slide has been suggested a few times.

while you are at it check cable adjustment....ain't your problem but, it happens more then you would think, where cables have stretched and you no longer get WFO

[ICANTD55]

Just keep swinging .LOL

Also agree could be lectrical related.

[L-]

YOu can take the air cleaner off and start the bike and use the throttle to see if the slide is opening.  It may be opening only part way also. Diaphragm may be pinched or a hole in it.  Install a clear fuel line to see if fuel runs out or a clear in line "bulb" or filter to check.  If it is the ignition I would replace with a DTT (Daytona Twin Tech).  I feel if it runs for a while, stops and then restarts it sounds like fuel.  Clogged petcock filter or gas cap not venting correctly.

L-

[Mix01FLHT]

change the battery, hook a jumper cable to the battery, but make sure you have a full charge, then try your test.   

[apendejo]

Long time ago my '93 Dyna was doing the same thing. Turned out the little tiny O-ring under the idle air fuel mixture screw had somehow cocked itself sideways in the bore. Just a thought.
AP

[Jeffd]

plug wires?

[harleytoprock]

Hi Folks. Some people have mentioned electrical/ ignition. I'm not headed in that direction yet as it will run and cruise at 40 or even 50 mph but only if the choke is pulled out. I still think its a fuel starving problem.
          Some people mention accel pump. Its not a momentary bog and then catches up. It just won't run at the above idle speeds unless the choke is pulled out. Even with no accel pump I should be able to slowly open the throttle and cruise. Not in this case. It just won't run unless choke is out but can idle with out the choke on.
         I picked up at a HD a new float needle and a slide. I'll put it together and see what happens.I still haven't looked at the petcock real close. I just wonder if a piece of something got stuck between the float needle and seat wedging the needle somewhat closed. If all else doesn't work I'll tie it to a tree and beat it with a stick.  :teeth:To be continued.

[Admiral Akbar]

Ya know, sounds like someone dumped a bunch of alcohol the the fuel.. I'd dump the tank and try fresh gas.
The main times I see this is when gas gets old or when I was trying to burn off a nitro/alcohol mix in a generator.. 15 gallons of it.. 

Max

[harleytoprock]

Max, Thanks for the reply. I had filled the tank up 30 miles ago. And the tank before that was all used that same day.( Week and half ago). Do you think if the last tank fill up had screwed up gas it would run ok for 30 miles and screw things up 30 miles later? Could maybe this last fill up had to much alcohol and messed up the rubber tipped float needle?
      I turn the petcock on and off many times in a fast and slow manner and the gas comes a gushen out consistently. So the petcock can pee alot better than I can.