Topic: VB44A 1981 CB650 Carburetor Slow Jet Revealed

[81cb650c]

I had a spare set of old VB44A carbs sitting around and decided it would be a good idea to sacrifice one to finally see what the pressed in slow jet looks like so others can get an idea of how impossible it is to clean.  There is no way to run a wire or guitar string through the jet because the idle circuit runs off at a 90 and 45 degree angle outside the jet so any attempt to run a wire through would result in simply hitting the bottom of where the jet is seated. Also i attempted to remove the jet with an easy out/heat first and thats a no go they are extremely pressed into place. Although the top and center of the jet was clogged and gummed up the actual small holes in the side of the jet and the passage ways in the carb body were clean. So if you are able to clear the center hole with it in place you may be all set. The depth from the top of the carb body that the jet is seated in to the bottom of the jet is 1 1/2 inch. Hopefully the following pictures will help others.

[Bigd3077]

So how can we clean them? I'm having a nightmare with my 81CB650

[aircraftgrade]

I bought an '82 CB650 and didn't even know about this in the '81 and earlier series carbs. How thankful I am I dodged that bullet.

Re: cleaning, shouldn't you still be able to spray carb cleaner in the hole and have it come out the other side in the venturi? If not, you could try soaking it in place, once you remove everything that isn't metal from the vicinity so it isn't eaten alive by the carb cleaner.

[81cb650c]

I believe the best way to clean them would be a combination of techniques such as ultrasonic cleaning, compressed air, carb cleaner and a correctly sized wire for the center of the jet. I am going to attempt to drill out and replace one of the jets on this set of carburetors with a screw in replacement to see if its possible.