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removing the carburetors


what you'll need:
Time needed: About a half-hour each for removal and installation. Plan on a little longer if it's the first time that you've ever pulled carburetors, because you'll want to linger on each hose to really understand where it goes and what it does. Once you've pulled the carbs at least once, it takes significantly less time.

  • hose clamp pliers (or needlenose pliers)
  • masking tape
  • pen

background.
Carburetors have historically been the scariest part of motorcycle mechanics for me. I'd rather disassemble an engine than a carburetor. Unfortunately, an interesting project came up with Peter's VTR1000F Superhawk, and it required pulling the carbs. Turns out, it really isn't that bad. Really.

Since there are about eight million different modifications or projects that you can do to the carbs once they're pulled, I'm only going to focus on the actual act of removing and installing the carburetors here.

To vastly over-generalize, all you really need to do to remove the carbs is remove all of the hoses that connect it to other parts of the motorcycle. The trick is remembering which hose went where when it's time to re-install the carbs. Therefore, I highly recommend keeping some masking tape and a pen handy. Whenever you pull off a hose, make two labels for that hose; stick one on the hose itself and one on the nipple. It doesn't really matter what you label them. The first time I pulled carbs, I anal-retentively labelled each hose with its proper name. After a while, though, laziness took over, and I took to labelling things "1", "2", etc. It doen't matter at all, as long as you label the nipple the same thing as the hose that connects to it.

pre-procedure.

procedure.
If you have a California model, the easiest hose to disconnect first is the one leading off of the top of the PAIR valve. Pull 'er off and label 'er.

Next, on the lower right-hand side of the rear carb, you'll find a coolant hose. This routes hot coolant from the engine past the carbs to prevent carburetor icing. The service manual recommends draining the radiator fluid so as not to spill any coolant from these hoses -- I found that they don't spill much if you're careful. Remove the hoses at your own risk, of course, but I don't think it's worth the trouble to remove the fairing and drain the coolant. Whichever way you choose to do it, go ahead and remove the hose clamp (hose clamp pliers or regular pliers are a necessity for this clamp) and pull off the coolant hose. Label it. You may find it helpful to tape a paper towel or a rag around the hose to keep it from spilling coolant accidentally.

At the lower left of the front carburetor is another coolant hose. Ditto the above instructions for it.

If you have a California model, go ahead and remove the EVAP hoses now. There are three that you need to remove -- one on top of the controls and two underneath. The pictures below will be more helpful than any verbal description that I could really give. Definitely label these three.

Next, look at the upper left-hand side of the rear carburetor. You'll see a cable sheath threaded into the carb housing. This is where the choke plunger assembly is attached to the carburetor. Gently pull the rubber boot off of the plastic nut, then use that plastic nut to unscrew the choke plunger assembly. Now you can gently pull it out of the carburetor.

Ditto these instructions for the front choke plunger assembly, found at the lower right-hand side of the front carburetor.

Now it's time to remove the throttle cables. They're found along the right side of the carb bank. You'll want to remove one cable at a time, and label which one is the top versus the bottom cable housing. For each cable, loosen the locknut on the cable housing and remove the screw from the throttle cable bracket.

Once the cable is free, you can remove the end of the cable from the bracket. Twist the thottle to lengthen or shorten the appropriate cable to make this easier.

Ditto the above instructions for the other throttle cable, again, remembering to label which one is the top and which one is the bottom.

On the right-hand side of the rear carburetor is an electrical connection. Disconnect it.

One of the main fuel lines comes off of the left side of the carburetor bank and runs through a bracket on the inside of the motorcycle's frame. Open up this bracket and free the fuel line.

There is still one hose left, underneath the front carburetor, but it's inaccessbile until we can lift up the carbs. So, hold that thought for a moment.

If you examine the rear carburetor, you'll see that there's a rubber piece between it and the rear cylinder -- this is the rear intake manifold. There are two clamps on the manifold: one to hold the carburetor onto it, and one to hold it onto the cylinder. With a #2 Philips screwdriver, loosen just the top clamp as much as you can.

The front intake manifold clamps are harder to get to. From the right-hand side of the bike, you'll see a small hole in the plastic that sits between the fairing and the carburetors (see the picture below so that you'll have a clue about what I'm talking about). Stick your long-shafted screwdriver in that hole (hey! I said to stop snickering!). If you look down at the carbs from the top, you should be able to see the screwdriver, and can hopefully manage to line it up with the top intake manifold clamp screw. Keep trying. You will prevail. Unscrew that sucker.

Now comes the fun part of pulling off the carburetors. Some times that I've done it, it's been relatively easy. Some times I've needed to pry them off with crowbars. Just get the darn things off however you can. Rubber mallets can be useful, I've heard. From friends.

If you've been very enthusiastic about pulling those carbs off, the last hose on the underside of the carb may very well have popped off on its own. If so, hunt it down and label it. If not, well, now you can reach it. Remove it and label it.

That's it! You're done!

installation.
To install, literally follow the above directions in reverse, noting the following:

I shouldn't really even need to say this, but don't forget to remove the masking tape labels. If one has fallen off into the bowels of the bike, go find it. This part of the bike tends to get hot, and melting masking tape neither smells good nor bodes well for whatever it melts upon.

If the intake manifolds came off of the engine for any reason, put them back. It is next to impossible to seat the intake manifolds back onto the cylinders when attached to the carbs. It is, however, easy to seat the carburetors onto the intake manifolds when said manifolds are attached to the engine. Seriously. Learn from my suffering.

Before you put the ends of the throttle cables back, slather them up with multi-purpose grease. Be prepared to get grease all over your fingers as you try to get the end of the cable to line up correctly with the metal housing.

Because Honda hates us, the threads on the choke plunger assembly are made of soft plastic. This makes it nice and easy to turn the threads into a nice mushy pulp. Thanks, Honda! If you're having a really hard time getting the choke plunger assemblies threaded back into the carbs, try cleaning the threads with your fingernail or a really small flathead screwdriver. I found that helps. The front one is just a pain in the ass to thread back in, even when the threads are clean. Keep at it. You'll get it.