GRB, I love when people smarter then me remember the full story, someone else I knew had a detailed explanation, he was a scuba diver and it is important to them as well. I remember just enough to be dangerous!!

Apparently that is the vacuum that will be created in your intake when the motor is running and producing your leak. So you are replicating that pressure, just in reverse so you can see the bubbles.

 

Happy to help!

 

I had a similar problem with a Sportster I rebuilt a few years ago. It turned out to be a combination of a faulty exhaust gasket, combined with a faulty sparkplug. Took me days trying to figure it out. Replaced both, and now she's running perfectly.

Start by checking to see if there is an exhaust leak at the heads.

 

So this issue is on a box stock 2003 wide-glide? Scotty is right about manifold mounts. They all have to be round.

 

C'mon 'Jesse', tell us what's happening !...j.f.

 

My shipment from CV Performance Santy Clause took longer to get to me so it will be this weekend. Fingers crossed.

 

Update ?...b.

 

Used sub carb from other bike and ran great. Solution? A real Keihin jet rather than the one remaining Dynojet part - a "48" jet.