Author Topic: Carbs - F1 or F2?  (Read 1855 times)

Offline StealthDJ

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Re: Carbs - F1 or F2?
« Reply #15 on: July 05, 2022, 09:30:12 AM »
Thanks - I'll start with the standard settings then and work from there.

And a couple of last stupid questions (they're back up on the bike, I'll stop soon, I promise!)

- How do you all route your fuel lines?  To me it looks like there are two holes in the mounting plate perfectly positioned for the lines to go through and then run across the top of the inlet rubbers before linking up.  Only other way I can see is to loop round underneath the carbs, or go round the end of the carbs and then underneath one inlet rubber to come up and join the fuel tap (as mine was, and it looked ugly).  Main problem is that I can't find any pictures of existing setups.

- The carb rebuild kits I got (I'm not using the jets, just the needle, gaskets and float assemblies) contained a small rubber o-ring which I can't identify and I definitely haven't removed any similar ones from the carbs.  Anyone hazard a guess as to where it should locate?  Did wonder if it was related to the air mixture screw, but I'm not sure how that'd work, or ever be retrievable.

Offline Spitfire

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Re: Carbs - F1 or F2?
« Reply #16 on: July 05, 2022, 12:09:16 PM »
Here's mine ready to go.

Could the O rings be for the carb tops.

Cheers

Dennis
1976 CB750F

1977 CB750F2 In bits

1964 BSA A65R In bits

Offline Lobo

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Re: Carbs - F1 or F2?
« Reply #17 on: July 05, 2022, 12:36:30 PM »
…very pretty.

The small neoprene O rings go around the brass carb drain screws to seal them to the bowl…
« Last Edit: July 05, 2022, 01:09:54 PM by Lobo »

Offline Lobo

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Re: Carbs - F1 or F2?
« Reply #18 on: July 05, 2022, 12:54:02 PM »
Stealth… the routing fuel lines up to you, best route with shortest route / least twists & turns / clear of all moving parts inc the choke mechanism. Here’s a pic of my rack as it came off the bike pre-resto; indeed the lines go through the holes you mention.
« Last Edit: July 05, 2022, 01:10:06 PM by Lobo »

Offline StealthDJ

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Re: Carbs - F1 or F2?
« Reply #19 on: July 05, 2022, 02:12:22 PM »
Thanks all.

re. the drain plugs - I guess that explains it.  I left them in place in the sonic cleaner after a previous bad experience when one sheared and left me with a continuously draining float bowl until I could find a replacement.  I tend to just remove the float bowl if I want to drain it.

Looks like there are some differences in the mounting plates - in mine below (throttle stop on the opposite side for a start) you can see two holes in the plate in direct line the with fuel unions.  I had the idea to run both pipes through these and then link up behind the carbs before going to the fuel tap.  My main concern was how close to the engine block it'd all be...

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Offline Skoti

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Re: Carbs - F1 or F2?
« Reply #20 on: July 05, 2022, 07:17:26 PM »
Best not use aftermarket carb needles and needle jets, they may leave you with a horrible flat spot and hesitation as the needle profile is not usually accurate enough.
(Been there, done that and wasted cash)

Better to do the job once and do it right, use original Honda needle jet kits:-  part number 16012 392 004.



Good luck

Skoti
Motorcycling is Life, anything B4 or after is just waiting...


1976 Honda CB750F1

 

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