carbs - no accelerator pump and auto petcock?!?!

[jum1210]

Hi Folks,

I'm a nubie to the site, having just bought an '83 750f (so I have been told, and according to the log book)

I am in the process of stripping, cleaning and reassembling the carbs and have stumbled on some issues. This is the guide I am using from MacGregor Carb Cleaning Services:

Honda_Carb_Manual_revD.pdf

This guide is very good, and almost matches my carbs exactly, except...

1)I have the autopetcock/spawn of satan/sos
2)I have no fuel accelerator pump in carb 2
3)I have no fuel accelerator pump rails

The carb numbers are VB52A. Has anyone seen this configuration before, is it normal, and should I take off the autopetcock as has been advised by others?

Thanks in advance

[icerigger]

The SOS does no harm as long as it is functioning well. Removing it will eliminate a potential problem and make diagnosing problems a bit simpler. I wouldn't remove it id it still works after all these years, but removing it will not hurt anything and will make you more aware of overflow problems if you don't turn the petcock off.

The VB52 carb is a European version and should have an accelerator pump according to the specs on motorcycleproject.com. Are the carb bodies missing the cross channels and the pump casting in carb #2 or are the tubes and linkage just missing? This could cause lean running as the open channels are an air leak in the flow. You'd also miss the response under full throttle.

[jum1210]

Thanks for this Icerigger. Let me show you a photo and see if that helps...

20131009_132807.jpg

this is a side shot of carb no.2, below is a pic of the entire rack looking at the float bowls, 1-4 from left to right

20130924_193710.jpg

here is a pick of the interior of float bowl 1 on the right(green, but now clean!) and float bowl 2 on the left

(the cleaner of the 2)20130925_140510.jpg

there were no accelerator pump rail tubes when I bought the bike (i knew little then, I know more now). Apparently on the bigger engine models these are missing anyway (1000 and 1100). Not sure if they have been taken by a previous owner or not.

The bike was not running when I purchased, but was assured with clean fuel and new battery it would. I did hear it turn, just not run. Hmmmmm?!?!?!

[icerigger]

These are definitely European carbs. Are you by any chance in the UK?

Apparently there are some without pumps. Your #2 body has the castings for the pump, but it looks like the channels aren't drilled and there's no spray nozzle in the carb throat. The pumpless bowl on #2 clinches it.

If you clean them they should be okay.

[jum1210]

Cheers for this Icerigger!

Yes I am in the uk. Will finish cleaning them up today and get them back together. Will let you know how I get on.

Thanks again!

Sent from Samsung Mobile

-------- Original message --------
From: "icerigger [via Honda CB750'S]" <[hidden email]>
Date:
To: jum1210 <[hidden email]>
Subject: Re: carbs - no accelerator pump and auto petcock?!?!


These are definitely European carbs. Are you by any chance in the UK?

Apparently there are some without pumps. Your #2 body has the castings for the pump, but it looks like the channels aren't drilled and there's no spray nozzle in the carb throat. The pumpless bowl on #2 clinches it.

If you clean them they should be okay.

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[jum1210]

Just for peoples info, I have the carbs back on the bike and they are all working perfectly. Thanks for the tips and chat, much appreciated!