Since DeQuincey asked about the Colortune in my carb project (a device which temporarilly replaces the spark plug and allows viewing the combustion mixture in the cylinder through a sightglass), I'll start a separate thread on it with his questions and a few things that are coupe-specific to help prevent pulling your hair out using it:
Here is the coupe-specific setup I came up with to keep from going crazy using this device, the Colortune is a useful piece of equipment but is fragile and a few mods will make it easier and quicker to use on our cars (yes that's my wife's placemat and yes that's leftover grime from the triple weber project, I will be buying her replacements very soon):
To the left is the Colortune plug and wire, this is 2 pieces that I have taped together, if you don't you'll have to try and feed the plug in then screw the wire onto it when in the cylinder hole - NFW in our cars so I wrapped them together with electrical tape.
The next piece is the small black plastic hex thingy that fits over the Colortune plug to tighten it, again it is impossible to fit this over it in the cylinder so I used an old OEM spark plug tool. These are perfect for the job because they are hollow and allow the wire from the Colortune to come up through the middle. I removed the piece of metal inside that was used to grab the plug so it is completely hollow. I put some tape on the black plastic piece and stuck in to the spark plug tool so it wouldn't come out. This is used for hand-tightening the Colortune.
Next is the black plastic sight tube - this is what you slide over the Colortune once you have it threaded and the wrench removed, it has a mirror attached (which sucks but works ok) so you can see the burn from above. It comes in 2 pieces and must be taped together for our use to prevent it coming back apart when removing it.
Next is my trusty magnetic telescoping nut/bolt/washer retriever (this thing is priceless when working on the engine). It is used to remove the annoying little copper washer that goes on the Colortune plug, the washer is not magnetic but by inserting the tool into the area and fishing several times in the vicinity of the plug hole, the washer, which falls off the plug into the hole (bot not into the engine cylinder), will come back out. This is the most annoying part of the procedure and why they didn't devise a better system of keeping the washer on I don't know. Others have said a little grease will hold the washer to the plug but it didn't work for me so I had to fish it out after each cylinder check.
The process is to warm the engine, remove the plug, insert the Colortune with the wire attached, turning it to start it threading. With the black plastic hex thing in the OEM plug tool, insert them over and down the wire onto the plug and just tighten it snug, not too much. Remove the tool and then slide the black tube/mirror over the wire and plug then attach the regular plug wire to the Colortune wire. Fire up the car and adjust mixture to desired blue color. Crappy pics but you can see the difference:
too rich (orange):
Just right (barely see the blue ring):
Once adjusted, remove the black tube, insert the OEM tool and remove the Colortune, if the copper washer doesn't come out with it then fish it out with something like the magnet rod that I use. Repeat for each cylinder if you have tripe webers or for each intake manifold for stock carbs.
More reading:
http://forums.pelicanparts.com/porsche-911-technical-forum/604309-colortune-carb-tuning.html
The Colortune is frustrating at first, but if you can manage the tool's fragility with the above tweaks it is pretty useful.
Here is the coupe-specific setup I came up with to keep from going crazy using this device, the Colortune is a useful piece of equipment but is fragile and a few mods will make it easier and quicker to use on our cars (yes that's my wife's placemat and yes that's leftover grime from the triple weber project, I will be buying her replacements very soon):
To the left is the Colortune plug and wire, this is 2 pieces that I have taped together, if you don't you'll have to try and feed the plug in then screw the wire onto it when in the cylinder hole - NFW in our cars so I wrapped them together with electrical tape.
The next piece is the small black plastic hex thingy that fits over the Colortune plug to tighten it, again it is impossible to fit this over it in the cylinder so I used an old OEM spark plug tool. These are perfect for the job because they are hollow and allow the wire from the Colortune to come up through the middle. I removed the piece of metal inside that was used to grab the plug so it is completely hollow. I put some tape on the black plastic piece and stuck in to the spark plug tool so it wouldn't come out. This is used for hand-tightening the Colortune.
Next is the black plastic sight tube - this is what you slide over the Colortune once you have it threaded and the wrench removed, it has a mirror attached (which sucks but works ok) so you can see the burn from above. It comes in 2 pieces and must be taped together for our use to prevent it coming back apart when removing it.
Next is my trusty magnetic telescoping nut/bolt/washer retriever (this thing is priceless when working on the engine). It is used to remove the annoying little copper washer that goes on the Colortune plug, the washer is not magnetic but by inserting the tool into the area and fishing several times in the vicinity of the plug hole, the washer, which falls off the plug into the hole (bot not into the engine cylinder), will come back out. This is the most annoying part of the procedure and why they didn't devise a better system of keeping the washer on I don't know. Others have said a little grease will hold the washer to the plug but it didn't work for me so I had to fish it out after each cylinder check.
The process is to warm the engine, remove the plug, insert the Colortune with the wire attached, turning it to start it threading. With the black plastic hex thing in the OEM plug tool, insert them over and down the wire onto the plug and just tighten it snug, not too much. Remove the tool and then slide the black tube/mirror over the wire and plug then attach the regular plug wire to the Colortune wire. Fire up the car and adjust mixture to desired blue color. Crappy pics but you can see the difference:
too rich (orange):
Just right (barely see the blue ring):
Once adjusted, remove the black tube, insert the OEM tool and remove the Colortune, if the copper washer doesn't come out with it then fish it out with something like the magnet rod that I use. Repeat for each cylinder if you have tripe webers or for each intake manifold for stock carbs.
More reading:
http://forums.pelicanparts.com/porsche-911-technical-forum/604309-colortune-carb-tuning.html
The Colortune is frustrating at first, but if you can manage the tool's fragility with the above tweaks it is pretty useful.
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