carbs, speedometers, etc.

[thrival]

I'm a newbie to working on vehicles, but have done the
minor servicing stuff, muffler pipes, etc. Last week
something electrical went out on my '85 C-20 steering
column and was cheaper to replace the whole column
with an available automatic shift coloumn (couldn't find
an original column locally.)

Starting problems necessitated pouring some liquid gas
into the carby; got it going, but now I can't exceed 25mph
or it bogs, like secondaries aren't opening. I checked and
linkage, lower butterfly appear OK, but just can't get up
to speed.

Also at some point speedometer cable appears to have
disconnected or broke. Tends to pull out at the tranny
(broken cable housing) but even when reinserted, doesn't
work, so think cable broke or disconnected up under the
dash. Manual has nothing to say. Any advice how to service
or replace?

[cooltoolguy]

my 86 with the q-jet would do that, bog down, the metering rods in the carb were stuck, would be going down the road and bleeeck! 20mph. I had to keep a hammer in the truck to whack the carb and loosen the rods. after a few times they loosened up and never had another problem. remove the air cleaner and look in the front of carb on top should she an opening (not the buttery flys, in front of them towards front of truck) spray some carb cleaner in there and tap lighty with a hammer.

[DnStClr]

You can reach up behind the instruments- and it's a heck of a reach- but it can be done- to see if the cable is still hooked up to the speedometer. It's secured by a spring clip so pulling on it shouldn't move the cable. But it sounds like the tranny end of the cable has pulled out of the plastic gear it's attached to. The gear might be trashed. They come as a set.
Can you hook your drill motor up to the end of the cable at the tranny and run the drill motor to see if the speedometer works?  

Don St.Clair
Culleoka Tn