CB72 Keyster Carb Kits - are they any good?

[Oggie400F]

Are the Keyster carb kits good quality?
These are the only kits I can find for CB72/CB77 Keihin PW22 carbs.
I’m assuming they are the standard kits for these carbs and are good quality but if not does anyone know of an alternative manufacturer/source of complete refurb kits.
Cheers

[Johnwebley]

Don't know about Keyster.

Have you tried Cruzimage

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[bruxby-clive]

I bought four keyster kits from Silvers for my 500, also used them on a 175 many years ago, worked a treat on both occasions.

[royhall]

Sometimes they are good sometimes not. Don't know why but their a bit hit and miss on quality. Same thing with Cruzinimage. Ash is the man on those, he may even have some genuine bits.

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[the-chauffeur]

In terms of getting the 72/77's to run, the kits themselves are pretty decent - although I have no idea quite how closely they replicate the original bits.  If the carbs are in decent shape, those kits will get you 90%+ of the original set up.

That said, steer clear of the air screws they supply in those kits; they're invariably the wrong shape and will make your life very difficult.  I stupidly swapped them on the CL77 and CA77 . . . should've realised from the fight the little o-rings were putting up with the air screws that something wasn't right.  Basically, they don't seal and so air is pulled in around the screws.

Eventually realised the air screws were causing the trouble, swapped back to the originals and everything settled down.  Last time I checked, Silvers had both the correct air screws and o-rings that fit on them.

[MrDavo]

Interesting. I used  a non original carb kit from Silvers on my CL450, out of necessity, and could not get a tickover until I went back to the original air screws and float needles, on the grounds that they weren’t visibly worn, and I knew they were right for the bike. 

That said, on that bike getting the float heights right was half the battle. A height gauge made from a business card, cut to the measurements in the workshop manual turned out to be essential, as well as free.

[Oggie400F]

Thanks for the advice.
The Keyster kits are mainly going to be used for all of the seals as these have perished and appear to be unobtainable as individual items.
All of the jets, needles and screws look like they are in good shape so the intention is to reuse as many as or all of them if possible.

[flatfour]

I've fitted these kits to both my CB750 and (when I owned it) CB500 with good results in both cases. They were sourced from DS.

[the-chauffeur]

Cool.

Never really understood why the aftermarket air screws for the 72/77's are quite so far away from the originals when the rest of the bits seem to be so close. 

About the only thing on the air screws that they get right is the thread/pitch.  Unfortunately, that's about enough to convince the naive (me) that they must be better than the originals because . . . newer(?!).  Nope. 

Comparing them will show the profile is totally wrong, and more often than not there's no recess/not a deep enough recess for the tiny o-ring to be fitted - either that or the recess is the wrong size/shape/location.  Makes reassembly almost impossible and if you do somehow manage to get them to fit, you're chasing air leaks

[Oggie400F]

The Keyster kits for the CB72 don't seem to be available on the DS sight although I have not called them to check.
The ones I have found are through the bay of fleas (Julies saying) from Germany.

[AshimotoK0]

https://nrp-carbs.co.uk/shop/index.php?route=product/search&search=cb72

Not that I am recommending any aftermarket carb kits Ian .. my philosophy is that if the original KeiHin parts are not excessively worn then reuse them.

Didn't know you had a Cb72 Ian or is it somebody elses?

[Oggie400F]

Hi Ashley
I don't own the bike, its my brother in law's.  I'm just helping him out trying to sort it out to get it running.
It had been stood in a dry motorcycle dealers workshop for at least 12 years. its in really quite nice overall condition apart from the tank corrosion and most of the rubber parts being hard or perished.

I'll take a look at the site you gave on the link, the link doesn't work btw, and would be grateful if you could let me know of any other sources of CB72 parts.

I'm still trying to persuade my brother in law to join the forum then he can get the help and advice first hand.
He isn't looking at restoring to a show bike, he just wants it sound and tidy so that he can potter around the local country lanes and villages.

The registration number is YFY 69, I don't know the engine and frame numbers but I'm sure its a UK bike as it shows as first registered 02/08/1963.

I am taking the tank to Russell in Knottingly this afternoon. Hopefully this will solve this problem at least.
Cheers.  Ian

[AshimotoK0]

Hmm .. link works for me 

Pity ..I gave a CB72 tank away free  a month or so back  that was slightly dented but clean inside.

Aaron Walkinshaw did a nice job rechroming my tank panels (and Bomber ones at the same time).

Graham Curtis (not on here) is the guru on CB72's .. he even rebuilds the cranks.

If there is anything specific you need I can always ask around. The Achilles heel on these bikes is the forward acting kickstart mechanism and 4-speed gearbox in general.
Personally I prefer the 250K0/K2's

[Oggie400F]

Thanks Ashley

I'll try the link again maybe its just my PC that doesn't like it.

Is the Graham Curtis the same one that restores the 400/4's too? If so, I have his contact details as he pressed my collector plates for me.

Its just the tank, the carbs, air filter assemblies and connecting hoses at the moment oh and possibly a speedo cable and speedo to headlight pod seal.

[AshimotoK0]

Thanks Ashley

I'll try the link again maybe its just my PC that doesn't like it.

Is the Graham Curtis the same one that restores the 400/4's too? If so, I have his contact details as he pressed my collector plates for me.

Its just the tank, the carbs, air filter assemblies and connecting hoses at the moment oh and possibly a speedo cable and speedo to headlight pod seal.

Yes same person Ian. Somebody in the VJMC refurbs the CB72/77 air filters as part-exchange,  at reasonable cost (well he did the last time I looked).