An inexpensive tool for correctly installing ST 1300 Throttle Body Insulators

[CYYJ]

The throttle body of the ST 1300 sits on top of four rubber insulators. These insulators connect the throttle body to the cylinder head intake and they prevent heat from being transmitted from the engine casing to the throttle body.

There are two clamps on each insulator, one at the bottom and one at the top. Instead of publishing a torque specification for these clamps, Honda specifies that the gap between the two ends of each clamp needs to be 10 mm for the lower (cylinder head) clamps, and 7 mm for the upper (throttle body) clamps. It is difficult to get a ruler or a caliper down there to measure the gap, so, I created my own measuring tool by cutting up a plastic credit-card size hotel room key. You could use an old credit card for the same purpose.

The photos below show how to make and use the tool.

Be aware that when you install the clamps on the insulator, there are little holes around the perimeter of the clamp that fit over nibs on the insulator. The lower and upper clamps are different part numbers. If you mix the clamps up, you can sort them out easily enough: the lower clamps have two holes in the perimeter, and the upper clamps have four holes in the perimeter.

When reinstalling clamps, pay close attention to correct 'orientation' of the JIS (Japanese Industrial Specification) screw-hole on each clamp. You want to be able to reach the screw-hole with a screwdriver after the throttle body has been installed. This means the screw-hole has to face the correct direction. When you are installing the lower clamps - before you install the throttle body - you have easy access from above, but once the throttle body has been installed, you will only be able to access the screw-holes on the lower clamps (without removing the throttle body) if you correctly oriented the clamps when you installed them. The photo at the bottom shows the only path the screwdriver will be able to take to get access to the screw-holes.

Michael

Making the tool from a plastic hotel room key


Page 1-15 of the ST 1300 Service Manual, showing the distance specifications


Checking for the correct gap using the tool


Correct orientation of screw-hole on clamps
The point of the arrow shows the approach that the JIS screwdriver will follow to reach the screw-holes on the clamps.

 

[Igofar]

The throttle body of the ST 1300 sits on top of four rubber insulators. These insulators connect the throttle body to the cylinder head intake and they prevent heat from being transmitted from the engine casing to the throttle body.

There are two clamps on each insulator, one at the bottom and one at the top. Instead of publishing a torque specification for these clamps, Honda specifies that the gap between the two ends of each clamp needs to be 10 mm for the lower (cylinder head) clamps, and 7 mm for the upper (throttle body) clamps. It is difficult to get a ruler or a caliper down there to measure the gap, so, I created my own measuring tool by cutting up a plastic credit-card size hotel room key. You could use an old credit card for the same purpose.

The photos below show how to make and use the tool.

Be aware that when you install the clamps on the insulator, there are little holes around the perimeter of the clamp that fit over nibs on the insulator. The lower and upper clamps are different part numbers. If you mix the clamps up, you can sort them out easily enough: the lower clamps have two holes in the perimeter, and the upper clamps have four holes in the perimeter.

When reinstalling clamps, pay close attention to correct 'orientation' of the JIS (Japanese Industrial Specification) screw-hole on each clamp. You want to be able to reach the screw-hole with a screwdriver after the throttle body has been installed. This means the screw-hole has to face the correct direction. When you are installing the lower clamps - before you install the throttle body - you have easy access from above, but once the throttle body has been installed, you will only be able to access the screw-holes on the lower clamps (without removing the throttle body) if you correctly oriented the clamps when you installed them. The photo at the bottom shows the only path the screwdriver will be able to take to get access to the screw-holes.

Michael

Making the tool from a plastic hotel room key


Page 1-15 of the ST 1300 Service Manual, showing the distance specifications


Checking for the correct gap using the tool


Correct orientation of screw-hole on clamps
The point of the arrow shows the approach that the JIS screwdriver will follow to reach the screw-holes on the clamps.

Nice pictures Michael (thanks) you can also use a flexible 1/4 inch drive tool (Snap-On TM615 USA) its about 15 inches long, has a 1/4 inch drive head for sockets, then put your JIS bit inside a 1/4 inch socket, and lift the rear corner of the mat and slip it straight forward to the clamp. This way you won't have to remove the radiator to go through the front.
I believe Bob posted some pictures of his Son doing this job, and it shows the correct entry points doing it that way.

 

[SMSW]

Doesn't the thermostat housing sit right about where your two red arrows cross (X)? Sure it is supported by the rubber hoses, but as I remember (from when I changed the stat) there was precious little play if you wanted to move it.

 

[SupraSabre]

Okay, let's hear how you remove said throttlebody? Was it a struggle?

 

[CYYJ]

Okay, let's hear how you remove said throttle body? Was it a struggle?

No, not much difficulty at all. I saw a picture that Dave D. (@dduelin) posted some time back (below), showing how he used a crowbar across the top of the frame to lever the throttle body assembly up, and I did exactly the same thing, using the same fabric straps attached to the structural portion of the throttle body.

It did take quite a bit of upwards force to free the throttle body from the insulators, but I was anticipating that based on what Dave D. wrote in his post.

Michael

David D's Throttle Body Removal Technique

 

[SupraSabre]

One trick I use is to remove the bracket bolts from the rear right brace (brace between the left and right set of throttlebodies). Then I use a small crowbar and GENTLY pry up on that rear right throttlebody. It will pop up with little strain and the rest will follow suit. (I only loosen the top insulator clamps.)

When putting them back in, put the bolts back in place, but not tight. I also add a little (very little) plumber's grease on the rubber of the insulators. They just pop right back in.

So far I've used this method on my 2004 #2 (several times), 2004 #1 & 2010!

 

[CYYJ]

Doesn't the thermostat housing sit right about where your two red arrows cross (X)?

Yes, it does, but if the clamps are correctly oriented (as they were on my moto, because no-one had touched them since the moto left the factory), it is possible to stuff a very long JIS screwdriver in a straight line along the path shown by the arrows and loosen the clamps. It just misses the thermostat & associated hoses. I'm pretty sure Honda designed things with that in mind.

Or, as Larry mentioned, to use a Snap-On TM615 tool with a 1/4 inch socket and a JIS bit in the end (see photo below) to do the same thing. I was able to use the long screwdriver, which I think is the preferred tool. The TM 615 gets a bit flaccid if you cannot support the far end, and my experience is that it is difficult to apply much torque when using this tool.

Michael

Snap-On TM 615 flexible 1/4 inch driver

 

[Honda-st-team]

Learned something new today

 

[paulcb]

My carbureted ST1100 has similar boots. When I replaced my boots, I replaced the JIS/Phillips screws on the clamps with allen screws. Makes for easy adjusting without having to push to maintain engagement, which keeps from spinning the clamps. Got that tip from someone on here.

 

[fnmag]

My carbureted ST1100 has similar boots. When I replaced my boots, I replaced the JIS/Phillips screws on the clamps with allen screws. Makes for easy adjusting without having to push to maintain engagement, which keeps from spinning the clamps. Got that tip from someone on here.

Excellent tip, thanks for posting.