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gk73a hose's help?

Posted: Sat Nov 30, 2013 8:13 pm
by tiinch
im looking to replace all my hose's on my gk73a. (fuel, breather, radiaor .etc)
only problem is there a bastard to come across!
anybody know where to find them or a set that will fit the gk? :pray:

Re: gk73a hose's help?

Posted: Sun Dec 01, 2013 7:08 pm
by panda
theres a member on here Gavin at jap4 that does samco hoses for cooling system for the 76a not sure if they fit or they do them for the 73a other hoses can be sourced from car supply shops or halfords.

Re: gk73a hose's help?

Posted: Mon Dec 02, 2013 11:32 am
by tiinch
nice one cheers for the help

Re: gk73a hose's help?

Posted: Mon Mar 11, 2019 2:28 pm
by Gsxr400luckystrike
Hello all,
I am new to the forum and a new Suzuki gsxr owner.

The bike is a 1990 gsxr400 gk73a

I have purchased a non running bike with the prospect of restoring it, now when I got the bike it was literally a engine in a frame and the rest was in boxes. I'm slowly but surely putting the bike back together but can't seem to figure out a hose location on the top of the carb rail.

I would add a pic so you can see the issue I'm having. But not sure how to.

The lower 'T'pipe on the carbs with a metal spring on it looks to be the fuel feed from the tank, the one I'm uncertain of is the upper 'T'pipe pipe in between carb 2&3?
Now it looks like a vacuum to me, but have been told one of the carb tops should have a vacuum feed
Ontop on one black cap but the engine I have doesn't have any pipes for that but it did have one of the small black nipples missing so I blanked it off with a spare bit of pipe. I was under the assumption these are only used for the carb balancing process and when not in use always blanked off????

Another issue I have is I have x2 nipples on my mikuni fuel tap, and a seperate thin pipe under the tank. 1nipple I'm guessing is the fuel feed to the carbs but what is the other nipple for??? What pipe leads to it?

Any help would be appreciated

Dale

Re: gk73a hose's help?

Posted: Mon Mar 11, 2019 10:23 pm
by moforockband
that carb top pipe should be vented to atmosphere, it allows the fuel in the float bowls to sit at the correct level and displaces the air in the carb bowls.
The pipe with the metal spring goes to the tap, yes.
There is only 2 pipes to the tap. 1 vacuum small pipe which leads to one of the plastic carb tops. (The other 3 carbs should have rubber blanks.) The other nipple I think is a blank on the casting.

I fitted a 34mm rh outlet manual tap, and blanked the 4th carb, as the vacuum taps are notorious for not doing what they're meant to do and flood the engine.

Re: gk73a hose's help?

Posted: Mon Mar 11, 2019 10:49 pm
by Gsxr400luckystrike
Thanks for the reply and help on the matter.

Right so which nipple on the back of the fuel tap runs to the carbs fuel feed and which is for vacuum to the carb plastic top?

I see on the tap one nipple is lower than another if that helps. Also where does the thin black rubber pipe under the tank run to because I'm guessing the thin hose ontop of the tank next to the filler cap must be the vent? ( I have seen on pics that pipe runs to the yoke top) thanks google!!

Does it matter which carb has the vacuum to the tap or can I use any?

It's hard work at the min with no manuals or anything to show where things go to, but your info is golden and much appreciated.

Re: gk73a hose's help?

Posted: Tue Mar 12, 2019 12:16 pm
by moforockband
This is what your tap should look like:
https://www.ebay.co.uk/itm/Suzuki-GSX40 ... ctupt=true

- little pipe on the back of the tap goes to carb top (vacuum)
- pipe from fuel cap is water drain or overflow, and that is vented near the sidestand
- metal shrouded pipe is fuel feed
- large rubber pipe from rocker cover goes to airbox

The fuel tap should only have 2 connections and should be impossible to get wrong. Just make sure it doesn't leak otherwise you can ruin the motor bores.

I have a cd I can send out for a small charitable contribution which has the 73a workshop and Japanese part number listings, and also shows the hose routings.
If you hunt around you may still find the 73a manual online.