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Hi Folks,

I'm really new at working on motorcycles and I could use some help with my carbs vaccum ports. I have a 1978 KZ650 SR, and I have to open ports here:

Damn, mixed that up. that would be 4 open ports in first pic and 2 in this pic.



Should I have lines running to them or block them off ?

those are overflow tubes you need 4 short hoses to drain below the bike in the event of an overflow so gas doesnt land on a potentially hot engine

oops posted on the first pic

the two in the second usually tee into the vaccuum valve on a petcock not sure on your bike though

Post edited by: btchalice, at: 2006/03/29 17:52

Sorry about the supe-sized pic, thought I had reduced it.

Hi btchalice,

Do you think I should try and re-run some lines to connect the top two with the petcock, or just cap them since the bike runs as is ?

Thanks,
-Brian

As far as I know only one line runs the vac on the petcock. I may be wrong on this, but the two lines could be for the "clean air" system. Seems like you could cap them off and see if everything works OK. If they were vac lines, the petcock wouldn't work at all when set "on" or "res", (if the petcock was working properly )it would only flow without vaccum on "prime". (at least on my bikes)
To determine if you have a vaccum petcock you need to look at its settings. On vaccum models there are "on","Res", and "Prime". Non-Vac Petcocks, I believe, have "On", "Res, and "off".
Check to see what petcock you have and that should determine what the lines are for.

BTW, could you post a supersize pic of the 2 lines (my eyes aren't as good as they used to be )

Post edited by: NOS, at: 2006/03/30 06:49

This link contains info on connecting your carburetors:

www.wgcarbs.com/88724.html

Thanks wiredgeorge, that page is Great !!! and NOS thanks for explaining the different petcocks, mine is a vaccum operated one.

Thank You,
-Brian