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After the Air Clearner its now the carbs - should I re-build

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keithtraffic:
So, managed to eventually remove the air cleaner (earlier post) and after a big struggle actually get the carbs off the bike! They are (as referred to in several other posts) the 'dreaded' PD types (PD 46A).

The original problem was that the carbs were leaking significantly from around the bowl seal and having removed the carbs and set them up on the bench, connected to the tank, I have confirmed this is definitely where the fuel is leaking from.

Having removed the bowls it looks like perhaps the last time somebody did take them apart the seals were not replaced - they looked pretty deformed and in a bad state - also the screws holding the bowls to the main carb bodies were not really done up very tightly - I was expecting a bit of a struggle here but they came undone with very little effort so I am wondering if this 'lack of tightness'  was contributing tot the problem?

In preparation I have already purchase new 'packing' kits for the carbs but here is the first problem - the top gasket in the kit has locating holes in a different arrangement to that which is on the bike (see below). Now the kit was supplied by David Silver as a substitution, so that might be the explanation but has anyone else seen this problem before?

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But now the BIG QUESTION - as the carbs are off the bike should I go for a complete rebuild at this stage or let sleeping dogs lie and just replace the bowl seals?

If the general recommendation is to go the whole way are there any good articles on how to do this - I have found one from the "Vintage Bike Builder" website which looks pretty good but wondered in there were others which I could refer to. I have noticed that both the Haynes Manual and the Honda Workshop Manual I have don't seem to actually cover the PD carbs!. Also is there a recommended kit of parts including all the jets etc - looking on this forum there does seem to have been problems with different jets being supplied which are not always correct!

Any advice on this would be welcome!

Johnwebley:
I don't know the PD carbs. But have a good look at things like the
Float needles. See if there is a wear ridge.
Also the needle in the slide.does that have wear marks.

Remove all jets and adjustable air screws. Clean thoroughly with spirit.
Fit new float bowl seals and with luck. It should be ok.

Sent from my SM-A750FN using Tapatalk

simonc:
Also dont know pd carbs so cannot comment on gaskets sorry. but clean clean clean/ check float heights/  :o

keithtraffic:
David Silver have been helpful (as usual) and offered an original gasket kit which looks like it will fit. But they also offer a complete re-build kit for not much more money.

Does anyone have experience of these (Carbs are PD46A)?

https://www.davidsilverspares.co.uk/parts/by-part-number/partnumber_PCRKCB550K3/

bruxby-clive:
I can't comment on your carbs, but the part number of the complete kit would suggest that it is a Keyster repair kit, I bought 4 of these for my CB500 K2 from Silvers and they worked first time, I have also used them on my KH250 and a Cb175, I like them, but plenty of people don't. My KH carbs eventually had to be cleaned 3 times each in my small ultrasonic cleaner, finally at a temperature of over 80 degrees C for around an hour each. I think people blame the repair kits when it is blocked airways in the carb that is causing the problem. Good luck whichever way you decide to proceed.

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