Carb bowl blocked port

Hi all, this seems such a basic problem but I'm stumped. One of the ports in a carb bowl is blocked solid. I tried soaking in solvent, ultrasonic cleaner, winding a small drill bit (by hand) and jamming & sealing a small tube in the larger hole then squirting with carb cleaner and high pressure brake cleaner. Any suggestions would be appreciated.

 

Heat won’t hurt the bowl. A drop or two of carb cleaner and propane torch. Just a bit of heat to make the cleaner boil. Keep a wet rag handy for flare ups.

 

You can boil it in a pot of water too.

 

The single wire out of a stainless wire brush is good. They take some prodding sometimes.

 

Like Franz said, boil it for about 15-20 minutes. The blow it out with carb cleaner. Boiling melts the varnish which has hardened, but then it needs to be blown out with carb cleaner followed with compressed air. If that doesn't work, you have a real problem on your hands.

 

The starter jet down in the bowl is removable on 1980 (and perhaps early 1981) 650 models, but is pressed-in-place (iow, non-removable) in all other models. Check to see if it has a straight-blade screwdriver slot in the top. If not, everyone else's solutions (heat/solvent/etc.) are the only way to do it. BTW, the passage is a size 40 (just like the pilot fuel jets on many Hitachi models), so that's .40mm, so you can use up to that size drill bit or wire safely/easily.

In some stubborn cases, you actually do have to drill thru it, it becomes like fossilized wood or similar.....

 

Success, thanks everyone for your help! I boiled the bowl for about 20 minutes & managed to force a very small amount of brake cleaner through the port. Then shone a torch in the hole & found there's a small brass jet down there, there is no screwdriver slot as shown in the photo. Chacal you're quite correct it does has a very small aperture. So I stuck a wire from an old wire brush down the centre of the jet and it worked a treat (thanks Minimutly).