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Carburettors

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Erny:
My experience with carbs rebuilt by Gerben, it was for 022A set, jets 40/100. All brass original Keihin.
As said here, Gerben work looks very good (even I'm not a fan of polished bowls).

However, funcionally vise I was never able to achieve good idling despite a lot of sync tries. Additionally, behaviour at lower RPMs not good (felt like too rich). First I replaced slow jets from 40 to 38 (new NOS Keihins). It improved a little but still, running engine between 2500-3000 felt too rich and rough.
Having cabs off the bike this spring and reading some forum thread pointing to sensitivity of emulsification tubes plus fact that my tubes were falling off the carb bodies when main jet is removed, I checked them into detail and compared with keyster replicas I bought some time ago.
Guess what - I found internal surface of hole rough / corroded.

As all outside dimensions and size/position of holes on tubes were the same as on Keyster replicas, I decided to put them in (I had to push them inside with some force, so they do not fall out by themselves). I did not change needles that required additional dissassmbly.

After bench sync only (bearing balls method) carbs installed - whoola! Bike idles much better, chain rattle almost gone. Additionaly runs great, smooth on lower RPMs, I can easily "cruise" on ~2500 RPMs and engine picks up easily w/o hesitation. So only simple change of tubes change bike behaviour a lot!

=> before deciding to use original old used tubes, check them inside. In this specific case originals are not always better than alternatives ;)

Attached pic comparing new Keyster (left) with OEM Keihin

AshimotoK0:
Ken . ... I just started bright zinc plating again after about ten years as I usually send mine to Allenchrome. However, their lead times and prices went right up last year plus my parts are mega rare and small CB92  parts that are nigh on impossible to replace unless you have ££££££.

I used to use Gateros for chemicals  but I am going to buy the zinc solution pre-mixed from YouPlate this time as they use potassium chloride/boric acid rather than ammonium chloride. Interesting that they don't recommend zinc/nickel for home use because of the difficulties in maintaining the electrolyte consistency.

I usually get my de-ionised water from Eurocarparts.

http://www.youplate.co.uk/zinc.html


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AshimotoK0:
Here is the YouPlate advice Ken

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deltarider:

--- Quote from: Erny on October 23, 2021, 07:35:08 PM ---[...] even I'm not a fan of polished bowls [...]
--- End quote ---
+1 Every now and then one sees these Honda's with parts polished to a degree they never ever had before, not even in the showrooms. Personally I prefer the original 'satin' look.

--- Quote ---Guess what - I found internal surface of hole rough / corroded.[...]
I had to push them inside with some force, so they do not fall out by themselves. [...]
--- End quote ---
In my experience just pushing them in gently, is good enough. No need to drive them in with a wooden stick like Marco demonstrates in one of his vids. When the main jet is pushed in as far as it goes, the tube will also be in position. For cleaning the tube's inside, use one of grandpa's pipe cleaners. Do not apply abrasive stuff. Maybe just a tiny bit of toothpaste or some cigar ash in water.

AshimotoK0:

--- Quote from: Oddjob on October 26, 2021, 06:24:07 PM ---
--- Quote from: AshimotoK0 on October 23, 2021, 10:10:20 PM ---Here is the YouPlate advice Ken

(Attachment Link)

--- End quote ---

That may be confined to where the solution is in the chemicals Ash, it seems to work when plating from anodes ok or I doubt that Gateros would sell the kit, according to them the result is 90% zinc and 10% nickel.

--- End quote ---

From what I can make out Gateros was started by a hobbyist (nowt wrong with that) but the Youplate people are professional plating suppliers that have starting selling to the home plating market and  thought their reasoning for not offering Zinc/Nickel was pretty convincing. By the way, Caswell Europe asked me to evaluate the power supply that Gateros sell and it was very poor build quality so. IMHO, don't be tempted to buy one.

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