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Intake leak

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Old May 10, 2016 | 02:21 PM
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Default Intake leak

Have an 88 electra glide. All of a sudden wouldn't idle below 3k rpms and could hear vacuum leak. Sprayed down and found intake gasket leaking. Read everything I could on it as I'm new to working on harley. Cleaned everything, greased the seals, went around tigreening bolts a little at a time. Went to start and just cranks then backfires out of carb with a lounge gunshot sound. Figuring I didn't get it sealed right I tried again. Having a heel of a time getting this right. Any advice or anyone close to Fredericksburg va area that might be able to help.
 
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Old May 10, 2016 | 03:06 PM
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Does your have the original carburator or has it been updated to a CV Carb? Are you sure you installed the intake seals in the right direction? Installation is pretty straight forward. The critical part is centering the intake manifold between the heads by equally tightening the intake flanges.
 
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Old May 10, 2016 | 03:16 PM
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CV carb is on. Chamfer side of seal towards flange and flat side towards head?
 
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Old May 10, 2016 | 03:26 PM
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Originally Posted by Paulzaplitny
CV carb is on. Chamfer side of seal towards flange and flat side towards head?
Yes..that is correct. I sounds like you may have a leaking diaphragm (vacuum slide) at the top of your carburetor. It will act very much like a leaking intake manifold. The fact that you said it happened all at once also points to this. Usually, a manifold leak is a gradual occurrence. To inspect, remove the 4 screws that hold the black plastic cap on top of the carb and inspect the rubber diaphragm on the slide . Watch some CV carb videos on YouTube. Back to the intake. Did you tighten one side of the intake to one of the heads and then tighten the other flange? If so, it will leak. They have to be tightened a little at a time so that the flange is equal distance between the heads. The intake, flanges and carb have to be aligned with each other before tightening down the allen head bolts. Other than that, I would inspect the intake for a crack. Also, make sure your vacuum line is connected to the carburetor. Its the one that goes to the voes and petcock.
 

Last edited by 89FLHTC; May 10, 2016 at 03:35 PM.
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Old May 10, 2016 | 03:31 PM
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Hang in there, you will get it figured out... Manifold centered between the heads? Any unequal torque or misalignment from the carb/air cleaner mounts creating gaps in the seal/manifold?

Are you sure your getting fuel? Or did not leave a vacuum line disconnected? Maybe pulled a wire accidently while working on the manifold...

Just throwing some things out there. Again, you will get it figured out. YD
 
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Old May 10, 2016 | 03:35 PM
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I'm pretty sure I everything is centered but I'll double check. I can see the seal coming out of flange on the intake side. It's that normal? I'm going to double check with the old seals that have already been compressed if they protrude out at all. Vacuum line is connected and definitely getting fuel. Quite the frustrating design.
 
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Old May 10, 2016 | 03:41 PM
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Again, the fact that it happedn all at once leads me to think the carb vacuum slide is leaking. Only 4 screws to check it.
 
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Old May 10, 2016 | 04:45 PM
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Thanks for the info 89
 
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Old May 10, 2016 | 04:49 PM
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Glad you found the problem! Here is a good source:
http://cv-performance.com/harley-cv-carburetor-parts
 
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Old May 11, 2016 | 04:21 AM
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Damm 89 that is a good hit on that one. Especially that he didn't take that top of the carb off, He only changed the seals
 
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