ZX-7R Fuel Hose Routing

Smithers · Post by **Smithers** » Tue Oct 19, 2010 9:37 pm

Just throwing up a picture of the fuel hoses and vent hose connected to the flat slides. Is this looking ok? I'm sure I have a CA model here because it has more than one nipple in the fuel input because it went to a small unit that allowed fuel to route back to the tank or somewhere. The top fitting are vent and the bottom are fuel feed right? I'm assembling this bike from pieces from storage so let me know if there is anything that doesn't look right.

Usually in the picture below the main fuel line from the pump (which has the protective spring around it) goes straight to the fuel input on the right side of the carb. But here for this CA model ZX-7R it has another smaller fuel input nipple on the left and you can see that I just put a fuel line to a T adapter to take care of it.

The clear lines are hose that is approved for oil and fuel use (although not high pressure). I used it for the vent line as I ran short of black fuel line and that stuff is a lot more expensive anyhow.

Smithers · Post by **Smithers** » Tue Oct 19, 2010 9:41 pm

Here is a shot of what I took off the bike. There is a charcoal canister routing solenoid thing on the left I believe. This took air from the charcoal canister and vented it back into the intake box. The part on the right connected to the left side fuel input to the carb I'm pretty sure.

57x · Post by **57x** » Sun Oct 24, 2010 1:54 am

All of the ZX7s had Kleen Air emissions. Cali bikes had more of it. You are correct to put in a 'T' for them. I have ten sets of these and these have two fuel inlets. You should route the vent lines to the airbox. This is not much of a pressurized box in the 91-92, but still best to vent to the box.

Smithers · Post by **Smithers** » Sun Oct 24, 2010 8:23 pm

Sounds good. I'll route the tubing into the airbox. I've seen another picture of a newer 7R that also vented the lines up into the air intake stream. I wish I had seen all of your ZX-7R project pictures from your gallery before I got down to business on this bike. The box is showing it's age but it's still functional. If I had more time I wouldn't mind moulding one up out of carbon fiber. Hmmm... maybe for the 1994 I should be getting soon.

57x · Post by **57x** » Sun Oct 24, 2010 11:20 pm

Go to Airtech Streamlining. You can get one that is ram air for the 91 made in carbon. Cheaper so far than making one myself so far, but I do get a fairly good discount from them.

Smithers · Post by **Smithers** » Mon Oct 25, 2010 2:46 pm

I can't believe they have all that ZX-7R stuff for sale. That's some dedication to have all those older bike parts for sale. Good to know.

Smithers · Post by **Smithers** » Thu Nov 04, 2010 3:24 pm

My mechanic buddy said that those clear tubes I have running down from the upper carb vents are overkill. We just cut them off about 2in from the top and pointed them down. Keeps things tidy. I have some bad news though. Once the fuel pump fired up the fuel started to flow... right out of the black fitting that feeds the fuel into the carbs. I tried putting a standard metric o-ring on each end and replacing it but that didn't help. We're going to order two new T-fittings for the fuel feed into the carbs and all the associated o-rings.

The blue arrow is where the fuel started coming out from:

Just for reference:

#1 arrow is pointing at one of the 3 long screws that must be unscrewed to remove the #1 carb on the end which is the only one I need to pull outward to get at the worn o-rings.
Once the above screws are out then you have to loosen the two screws that hold the cover on top so that you can loosen the hardware inside which allows the carb to pull from the throttle slide actuator that comes inside the carb body.
These arrows point to the old fuel line that normalized the fuel level between the carbs. These were rock hard in my case so they were basically glued to the nipples probably from the engine heat and old age combined. Just cut them off because they sure won't come off nicely unless recently replaced.

So once I pulled the end carb off it was pretty obvious that the seals on each side of the fitting (blue arrow) were brittle from old age. Tomorrow I'll have to place an order for a set of them. I'm tempted to replace the ones on the same fitting to the right but it's not leaking and it would double the work I have to do at this point. It's difficult to remove everything while taking the carbs apart from each other and you really need a second set of hands to help hold everything together while you assemble them. You will find out if you are attempting this.

These ZX-7 carbs are quite a workout let me tell you. And of course separating the carbs requires that you replace all the short old fuel hoses and vent hoses in between them. Luckily I had enough Motion Pro line to go inplace so now it's really easy to get them apart for servicing.

Smithers · Post by **Smithers** » Thu Nov 04, 2010 10:45 pm

If I recall from reading the manual the fitting (blue arrow) was only found on the California models so I will be looking for the 49 state carb fitting so it will be a solid tube which will get rid of the T. We just need one line delivering fuel here.

If those dumb little seals weren't leaking I would have fired it up today.

I actually tried some seals from an o-ring set I have in my garage but they just wouldn't hold the fuel back. These little suckers have to be tight. So don't waste your time like I did trying some universal o-rings. And check your throttle play at this point.

Also a good safety call: If your throttle doesn't snap back when you are assembling your carbs then find out why not so you don't find your bike trying to get away from you. I needed to adjust the throttle cable slack as they were too tight and holding up the throttle motion when you would let off.