There's like burn reside on and under the diaphragm. Is that normal?

BTW after unplugging the mixture screw, I found it was set to 1.5 turns. Way too lean, right?

 

No, CV Performance has replacement vacuum slides. 1.5 is probably a bit lean, open it up one turn.

John

 

Ha there goes another 7 business days. This is what I was afraid of - down time in the middle of the season.

I am more concerned about what caused the smoke/burn residue inside the carb. It doesn't exactly spell safety... Thoughts?

 

Probably caused by "cough" from lean condition. A proper tune should eliminate the issue.

John

 

I put the carb back on with the new jets 45/170. Fired it up and it sounds all f'd up now.

At first it won't idle so I increased the rpms with the idle screw. The air fuel mixture screw is at 2.5 turns. I had it running for about 15 minutes in the garage by either blipping the throttle or using the choke, then I went out for a ride - when warm it idles really high - at the stop, I just release the clutch and it goes. Back in the garage, I lowered the rpms - it just doesn't sound right - it sounds like only once cylinder is firing. Fiddling with the idle screw didn't help. I played with the mixture screw - anywhere between 1.5 and 3 turns - it seems lean overall as if I rev it, it takes like 10 seconds to calm down. Misfires left and right too...

I knew it wasn't going to be simple, but this is all over the place. Where do I start from now?

Something interesting - there's gasoline now where the arrow points to

 

A "hanging" idle is usually a symptom of a vacuum leak. Is your fuel inlet elbow made of black plastic? They can easily crack and leak fuel. A replacement inlet of all brass is available. I had to install one on my bike. Did you replace the intake manifold seals and install the manifold correctly (i.e. tighten manifold bolts after carb is correctly positioned). If it runs, we can probably get it straightened out. Try to ascertain where the fuel is leaking, check that fuel inlet if it's plastic.

John

 

The fuel inlet is brass. I also replaced the hose clamp. I only changed the rubber seal that goes to the carb as I couldn't take off the manifold intake. I'll research hanging idle
Thanks as always for your fast response!
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A thorough carb rebuild is not for the inexperienced, or the faint of heart. There are some good carb rebuild services out there. You send your carb to them, and then you get it back in a week, They replace everything that they find wrong. I have used them and upon install my bike ran like new. I just needed to set the idle. Check on e-Bay for a store called Carb King My carb came back looking like new. Your carb slide and diaphram looks real bad, With all that soot in there I just know that you need a thorough cleaning/rebuild and a new slide.

Good luck...!

 

Thank you. This is not my first carb rebuild job, tho it's first on a harley. I've used 2 cans of carb cleaner to clean and polish this puppy and given the new jets, it should be OK. Yes, I kept the old vacuum slide and cleaned it well too. (the new one arrives next week) No holes or tears on it. The original setup was generally fine, with the occasional caugh so in theory it should all be be good.
I'm impatient to try putting back the original intake seal as it too seemed OK. I'm more inclined to think that it's an air leak due to the installation...

Question - can you remount the carb without messing with the intake manifold?
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Yes, just don't move the mouth of the manifold up or down. So, you did not change the two seals that mate the manifold to the heads? Those are usually the ones that leak, as they get pretty hot being mated to the heads. If you did not, I suspect some movement of the manifold caused them to leak, they get hard over time and any movement could cause leaks.

John