CB550K3 PD46A stuck throttle slides advice required

[davidrsmith]

Hi

I have just bought a CB550K3 which I am restoring, I have taken the carburetors off as a block of four because the throttles slides are stuck in position.
I have taken the carb caps off and taken out the 4 screws that connects the throttle arms in each carb to the throttle shaft.

Carb 1 & 4 throttle slides seem to move freely but 2 & 3 are stuck, I have also taken the float bowls off and removed the emulsion tubes, there is a lot of hardened petrol residue in the bowl and around the floats and jets.

What is the best way to clean this residue off and what is the best way to free the throttle slides in carbs 2 & 3.


many thanks
Dave 

[AshimotoK0]

I freed some slides off last week by immersion in boiling water. It softened the varnishy deposit. Done it a few times ..always works for me.

[matthewmosse]

Might be an idea to ultra sonic clean them, whilst giving better economy is the cb550k3 carbs forte, they do block easier so I might think an ultra sonic bath would be a good start for them followed by getting fuel with redex in there a good few days before trying to start it. I just bough a commercial mower with a caked up carb, started off as a total none starter, everthing gummed up badly, that was running fairly well after jetting carb cleaner into the carb and redex and new fuel into the tank the afternoon it arrived and leaving it to stand overnight. It arrived with the throttle leavers stuck fast by gummy old fuel, even the choke needed freeing off with carb cleaner and a pry with a screwdriver.

[peterengland]

The guy who works on all the old classics round here swears by getting the engine hot then disconnecting the petrol feed and connecting to a bottle of brake cleaner, he says it will run like a bag of poo but the carbs will be purged. Not tried this myself as I have had no need to, but he has and reckons it works just fine.

[matthewmosse]

Both brake and carb cleaner will clear a fair number of blockages, and engines will start and run on it, not run well, but being strong solvents they will help strip stale fuel off components. Trouble is it won't shift lumps of rust or corroded alloy oxide, as I am finding with a stubborn kohler mower engine that will not rev out under load, pretty sure its a lump of crud in a fuel or air drilling, but aerolsols and redex plus an overhaul kit has failed to get it consistently working.

[JamesH]

Boil them in water to remove the slides as Ash suggested. Works every time for me.