majastre a écrit :ho erreur sur ton carbu c'est une 500 donc des 069a c'est pour une 750 donc il n'ont rien a voir j'ai rectifié le post plus haut car j'ai mal vu la photo mais ce soir ça a fait tilt excuses moi
ton truc cassé peut se reparer il faut percer e haut en bas mettre un insert et coller a l'araldite mais c'est du boulot ce qu'il te faut trouver c'est une rampe de 500 four ou a la rigueur une rampe de 550 f1 ( 649A ) pou le tender de chaine de distri il faut soulever les cylindres sinon ça rentre pas dans l'ergot du carter au fond quand on remonte lever seulement la culasse ne suffit pas et comme on soulève le bloc cylindre il faut changer le joint emabse donc faut tout demonter
là c'est neuf ooopppssss!!!
https://www.ebay.fr/itm/NEU-Original-Ve ... SweW5VUIzx
Bonsoir majastre
Du coup ça fait deux soirées que je passe à chercher des infos et je viens de tomber sur une réponse qui me plait ( et qui m'arrangerait bien ), en voici le contenu, ça me semble tenir la route vu que les codes, 069A ou 627B sont frappés après fonderie ou assemblage et non moulés ...
Tu lis l'anglais ?
Je cite ! :
The carb body castings were the same for the two model carbs. Internal parts varied to match requirements of the engine's breathing characteristics. The castings were then stamped 627B, 069A, 022A, etc. to identify what parts were installed inside them and where the needle clip was set (this is a set up number).
Both carbs have the same breathing capacity as they both have 22mm bores. It is the mixture at any given throttle setting that is different between them. If the only change you have made to the bike is a 4 into 2, I would be inclined to transfer all the 627B internal hard parts (not gaskets and orings), over to the 069A body stamped carbs. This would give them the same setup as 627B carbs native to the CB500. And, to be kind to future owners or mechanics of the bike, the setup stamping on the carb body should be altered accordingly, so there is a visual indication externally that the carbs are not what they were when they left the factory.
The only exception to the parts transfer might be the Idle Air bleed screw, I suppose. These have a different tapered tip and are solid vs hollow in tip design. I'm uncertain if the carb bodies had seats machined into them to match the tapered tip, or whether there would be some sort of performance issue with the mismatch. But, from this aspect, the 069A carbs are "the most different" from those found on the CB500. For a conversion subject, I'd rather see a 627B conversion from a 022A set than a 069A set. However, you should move the following parts in either case:
Slow jet
Main jet
Main emulsion tubes
Slide needle (use clip setting for CB500)
optional:
The idle Air Bleed Screw. (I don't know what, if any effect this may have on final correct setting.)
About the 4 into 2:
My 74 CB550 with 022A carbs ran fine for 15 years with the stock carb setings and 4 into 2 exhaust. I changed nothing in the carbs when I changed back to 4 into 4 and it still runs great.
Quote
But.......the 069A's were built for a 550, not a 500. They should breathe slightly more as a result of the extra 50 cc's. That will also lean things out if I'm thinking clearly - still on my first cup of joe here.
Then venturi effect is reliant on airflow mass. Increased displacement increases the mass. In short, higher displacement sucks harder on the jets for a given RPM, causing them to flow more, making the mixture richer. Air filtration changes likley have a greater effect on jet selection. Note, however, that the CB500 has #40 slows, and the CB550 has #38 slows in stock form. Seems reasonable to assume this change was a reaction to the increased displacement.
Cheers,
Logged
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100
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