Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: Trigger on June 02, 2018, 01:19:02 PM

Title: F2 tank with K6 carbs, problem
Post by: Trigger on June 02, 2018, 01:19:02 PM
Just finishing off a little project and came across a problem. The fuel tap on the F2 tank fouls the choke lever once the fuel pipe is on. I know on the F1 the tap had a rear fitting for the pipe but, though I have a F1 tap, it is a different thread. Have tried a reverse outlet tap but, the pipe bends up against the rocker cover.

Anyone come across this problem before and any ideas on how to get round it ?

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Title: Re: F2 tank with K6 carbs, problem
Post by: hairygit on June 02, 2018, 01:27:53 PM
Probably because the F2 had pd carbs. Will the F1 tap accept the securing nut so you could fit the F1 tap into the gland nut from the F2 tap.
Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 02, 2018, 01:36:16 PM
Probably because the F2 had pd carbs. Will the F1 tap accept the securing nut so you could fit the F1 tap into the gland nut from the F2 tap.


Different size gland nut  ;)
Title: Re: F2 tank with K6 carbs, problem
Post by: JamesH on June 02, 2018, 01:38:19 PM
Might have to use a pingel tap Graham..
Title: Re: F2 tank with K6 carbs, problem
Post by: hairygit on June 02, 2018, 01:45:02 PM
Unscrew the gland nut completely from both taps, then see if the thread sizes on the tap bodies are the same, if they are put the F1 body into the F2 nut.
Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 02, 2018, 01:57:59 PM
Different size bodies mate  ;)


[attachimg=1]
Title: Re: F2 tank with K6 carbs, problem
Post by: hairygit on June 02, 2018, 02:16:02 PM
Oh well, it was just a thought The one in the middle looks like a pattern one.

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Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 02, 2018, 02:46:48 PM
left one leaks OEM, middle one £2.99 and put new Viton 0 rings in and doesn't leak, one on the right is OEM and cost £60, doesn't fit  ;)
Title: Re: F2 tank with K6 carbs, problem
Post by: hairygit on June 02, 2018, 03:12:20 PM
Depends if you have a lathe, but you could make a sleeve for the tank spigot, as in make an internal thread to suit the tank thread, with an external thread to suit the F1 tap, but you'd need to use ptfe tape when attaching to the tank thread to avoid leaking or weeping. Shouldn't be too difficult with your engineering background!
Title: Re: F2 tank with K6 carbs, problem
Post by: K2-K6 on June 02, 2018, 04:13:38 PM
Just had a look at my cbx750 and the tap has a rear exit for fuel plus a rhs (looking face on to the tap) vac switch line.  It's very compact and looks likely would do the job as the vac line just taps into to carb sync port on no2.

The big question is the threads. I've not taken it out but it's 22mm across flats for the collar. Tank spigott looks much smaller but without dismantling I can't give you the thread size.
Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 02, 2018, 09:37:49 PM
Did have a look at a few taps with vac on them and dug some old ones out to find that the vac housing sticks out too far.
The thread I am dealing with is M16 x 1.5.
Title: Re: F2 tank with K6 carbs, problem
Post by: K2-K6 on June 02, 2018, 10:50:28 PM
The vac on this one is pretty small and looks well within the outlet stub in your original picture,  so from that aspect looks possible.

I'll keep an eye on here to see if you solve it before I get to look at this one. I'm working on it next week so if more spec's are needed then I'll post them for you.

Nigel.
Title: Re: F2 tank with K6 carbs, problem
Post by: neat street on June 03, 2018, 02:29:34 PM
Could you make a short `elbow` extension? just a thought?
Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 03, 2018, 04:44:57 PM
The vac on this one is pretty small and looks well within the outlet stub in your original picture,  so from that aspect looks possible.

I'll keep an eye on here to see if you solve it before I get to look at this one. I'm working on it next week so if more spec's are needed then I'll post them for you.

Nigel.

Cheers Nigel, did have a look about for a CBX tap, not ready availably on those. Got it sorted just by turning the tap round a quarter so, the tap lever is facing backwards and the outlet is now at the rear. Not perfect but, it will do.
Title: Re: F2 tank with K6 carbs, problem
Post by: Green1 on June 04, 2018, 07:12:08 PM
I was going to suggest just turning the tap but thought you would just laugh at my simple but rather crappy solution.  ;) 
Title: Re: F2 tank with K6 carbs, problem
Post by: UK Pete on June 05, 2018, 08:13:50 AM
Tell us more about this project bike is it f2 with k engine k with f2 tank sounds interesting

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Title: Re: F2 tank with K6 carbs, problem
Post by: hairygit on June 05, 2018, 08:28:34 AM
I don't believe you did that Trig! A man of your skills and reputation resorting to a bodge like that, or is it a case of the customer not wanting to spend what's needed to do the job properly?
Title: Re: F2 tank with K6 carbs, problem
Post by: Nurse Julie on June 05, 2018, 08:48:19 AM
I don't believe you did that Trig! A man of your skills and reputation resorting to a bodge like that, or is it a case of the customer not wanting to spend what's needed to do the job properly?
Trig IS the customer Hairy. Ita a bitsa he is buildings for himself out of bikes / bits laying around at home. You should know he would never, ever do a bodge on anything belonging to a customer.
Title: Re: F2 tank with K6 carbs, problem
Post by: hairygit on June 05, 2018, 09:03:11 AM
Even so! Surely the best advert for his services would be everything done properly on his own bike?

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Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 05, 2018, 09:08:41 AM
It is not a bodge, it is an adaption. Very easy to access the tap. I will go back to it at a later date, when the sun is not shining ;)

I would never bodge with PTFE tape  >:(

[attachimg=1]
Title: Re: F2 tank with K6 carbs, problem
Post by: Trigger on June 05, 2018, 08:48:36 PM
Shorten the choke lever, looks easy enough to do. By shorten I mean shorten the shaft length not the lever itself.

Would not work Ken. It is not just the choke lever, it is the linkage as well. Look at pic one and imagine the fuel tap hose.
Title: Re: F2 tank with K6 carbs, problem
Post by: Green1 on June 05, 2018, 09:13:03 PM
Just a thought can the hole rod assembly be mounted on the back of the carbs?
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