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Fuel Height

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Steris:
Hi oddjob

No they are the original's.  I bought 4 repair kits but the needles are slightly longer than the original's and with them in you can't get the fuel level  high enough. 

Steris:
I've set one carb at 22mm and one at 26mm both with sight tubes attached, and there is only a slight difference in fuel level. I left them over night with a good head of fuel feeding them and the level was still the same this morning  :D so i will go back to the 22mm float height and fit them back to the bike, but I'm sure they will leak again once I've refitted them  :(. If the level is too high will this make the bike run rich on tick over (on the pilot jet)?

bruxby-clive:
Hi Andrew

I had similar problems when I restored my KH, just couldn't get it to idle or run properly even with the carbs having been blasted in an aqua jet and then ultrasonically cleaned. After the 2nd or 3rd ultrasonic cleaning and out of desperation, I put them back into the cleaner again for an hour each turning them half way through at 75 degrees, I was amazed at how much muck came out but after this the bike would idle and pull cleanly. I would try cleaning them again. I came to the conclusion that some of the airways in the carb must have been blocked with old fuel. 

K2-K6:
"If the level is too high will this make the bike run rich on tick over (on the pilot jet)?" Yes but it's not a drastic change and more of an influence than absolute.  Obviously it's ideal to be as close as possible to judge.

Picking up on what bruxby-clive noted,  the idle circuit is drawing mixture from the float bowls by vacuum drop in venturi. This is modulated by the air adjustment screw to change the mixture ratio, but if the air passage leading to the screw is impaired then the vacuum pulls "full" fuel through the pilot jet. So in effect it's easily too rich if they are not fully clean.

One way to give an indication is with it running,  then try each airscrew individually to see if that cylinder will range from rich (fully closed by turning inwards) to essentially too lean at about 3 full turns out.  If you can't hear the cylinder changing much then that's an indication of the air passage still being partially blocked. You're dealing with very small volumes in these carbs,  with any impairment making quite a % difference to the mixture.

You could end up with different settings on each airscrew and different from manual spec too.  If you give each cylinder what it needs then discuss if they look really wonky as to what may be affecting it.

Steris:
I think I will give them all  another hour in the ultrasonic Bath then try again,  thanks for all your help so far, I will let you know how I get on over the weekend 🙂🙂

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