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Help-Carb cleaning!

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chrisr58:
Can anyone tell me the procedure to follow when cleaning the carbs on my 550 k3 without disturbing the balancing or removing more than necessary. Is there anything I need to buy in preparation that experience shows I will definitely need?
Thanks

SteveD CB500K0:
If they have been sitting for years with fuel in them they will be well gummed up and nothing will get your bike running properly other than a full strip and clean.

You can buy carb kits if you like (I didn't).

Take them apart and lay out all the pieces. Don't let the dog in the garage...

Soak in cellulose thinners and blow out the tiny holes around the jets with compressed air (I used aerosol carb cleaner - but it's expensive)

Reassemble. You may find that you do need gaskets and/or o-rings, in which case the carb kits are probably the only option.

I'm afraid that it is an iterative process. I've never got it right first time. Either the float bowls overflow or there's still something in the slow-running jets stopping smooth operation.

Good luck and let us know how you get on!

Dave M:
I've just done mine. I removed the floats along with the idle and main jets and also the float valves. I kept all the bits from each carb together and separate from the others.

I cleaned the jets by soaking in cellulose thinners and blowing clear with aerosol carb cleaner. I also removed the idle screws and springs and soaked the screws in thinners too.

The main jets and float valves had rubber seals on so I filled the insides up with thinners using a small syringe so I didn't destroy the seals. Again I blew out with carb cleaner after soaking.

I also injected thinners into the orifices in the carb body and after soaking blew them out with cleaner.

I've now reassembled them and checked the float heights, which were ok, and I've not got any bits left over!

I've refitted the air screws and set them to spec so all I've got to do now is put the carbs back on. Hope that's easier than getting them off!

I'll let you know how I get on and whether it was worth doing.

Best of luck Chris.

Dave M:
Just a quick update on progress.

Removing the carbs was quite difficult and resulted in bent jubilee clips and distorted airbox to carb rubbers so replacing them wasn't going to be very easy either.

I considered various options and only having 2 hands and no mechanic trained spiders available I found a reasonably straightforward method.

I replaced the inlet manifold rubbers and tightened them up fully. Then, without the airbox, I mounted the carbs onto the rubbers and tightened them up fully as well. This now left me with 2 hands and only the airbox to fit.

There was no way that the airbox was going to fit in with the carbs on so I removed the battery and the battery tray. By sliding the airbox in through the gap where the battery was I was able to wiggle and ease the box and rubbers past the carbs and into position. It was then just a matter of connecting the airbox rubbers to the carb and tightening the clips up.

NOTE: Before you push the airbox onto the carbs check that the lug on the rubbers on cylinders 1 & 4 line up with the datum marks that are moulded into the airbox. They're simple to see using a torch and the the rubbers rotate quite easily. If you don't do this the angle will be wrong and the rubbers will not sit properly on the carbs.

I've now replaced the air filter housing and tightened that up so all I've got left to do is re-fit the clutch and throttle cables, replace the battery tray and battery and then try and get it running again.

It's been an interesting evening and so far I'm still happy.

Watch this space...

Bryanj:
The K3 has pressed in pilot jets which need to be removed to clean properly. Using mole grips Grip tightly, without crushing, and pull and twist at the same time.

Refit with a light tap from a soft faced hammer

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