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carb help please

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neat street:
Hi Guys
I am having problems with No1 carb. it seems like its not letting fuel through. normally to test this you can undo the balance screw and squirt some WD40 or similar into the hole and if the engine picks up, you know fuel is not getting through. but when I undo the screw, the engine revs up and exhaust gets hot without the added WD40 (normally it would slow a little before squirting the WD). in some ways this is good news, but where should I look for the fault/blockage-airway? any ideas/solutions would be welcome.
Thanks in advance

John

Johnwebley:
check its not getting to much fuel,

 by removing the screw you let just air in,as it runs better,and the pipe heats,it seems over rich,

what colour is the plug?
any petrol puddles on the floor?

 remove the 4 over flow pipes from the float bowl,see if any drip,

neat street:
Hi John
Thanks for your reply, tried the fuel bowls/overflow, all is OK. The problem when checking the plug is that it only fires when the vacuum test screw is off, so will give me a false reading on the plug? No petrol issues. I am not sure if by undoing the vacuum screw it creates a vortex and forces more fuel through? have checked the jets and all is clear there. not sure where to look next?

John

neat street:
Hi all, just a thought, my rubber connector boots are probably the originals and quite hard. when I cleaned and checked the carbs, could this one not be sealing properly and creating these symptoms? if so, can anyone recommend good quality replacements please?
Thanks in advance
John

hairygit:
Genuine ones seem to still be available, not cheap, but Honda quality, and don't use jubilee clips to secure them, use the proper bands.

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