Carbs hanging up.

Cirerite · Post by **Cirerite** » Sun May 08, 2016 10:25 am

Having trouble with my 62 carbs. When rebuilt and bench tested the slides moved freely and easily. When placed on the bike they seem to twist or tweak when tightened down. Backed the nuts off a bit and they worked ok. Now that it got cold last night they are back to sticking in the open position. Any thoughts how to remedy this?

DianneB · Post by **DianneB** » Sun May 08, 2016 2:41 pm

I had a CB77 that did that back in the 1960s. It would stick every damned time if over-tightened - I once met the cops at 100MPH. All you had to do was back the nuts off a little and everything would be fine. (I got out of the ticket by taking it to a motor officer, tightening the nuts, and telling him to take it for a ride. The carbs stuck! He had to shut the ignition off to stop. He tore up the ticket LOL!)

I am pretty sure that either the face of the carb or the flange it mounted to was not perfectly flat. You could wrap a piece of emery around a piece of heavy glass or flat steel - be SURE it is flat! - and see what pattern you get when you run it over the carb face and the flange.

G-Man · Post by **G-Man** » Sun May 08, 2016 4:19 pm

The carb flange will look like this when you start with the wet-or-dry.

Once it is flat it will look more like this.

G

Nick · Post by **Nick** » Thu Jun 09, 2016 12:54 am

After surfacing the flange as shown above, install a new 0-ring with grease on it. Once installed on the carb, the 0-ring must protrude a bit from the carb flange. When tightening the carb nuts, only tighten enough to compress the 0-ring and bring the flange flush with the intake manifold. The nuts should not be tight. To prevent the nuts from loosening use locking nuts and/or the standard lock washers.

If the slide still sticks (and any fuel residue has been removed from the slide and carb) it means the carb body is warped. Get back to us if it is.....

The slide in my Dream started hanging up recently. Took it apart and found a lot of dried fuel residue on it. Cleaned it off and good as new!

When I have been unable to find the right size 0-ring, I simply find one that is larger but which has the needed thickness. I then cut the 0-ring to size (cutting at an angle and ensuring a close joint) and install with sticky grease. Works fine.