The COLORTUNE is a fantastic tool! Takes the guesswork out of setting the fuel mixture. No more plug reads, or chop tests. You could still do those things if you want to. I would recommend getting your hands on one of these tools first. For me, this will always be an essential setup procedure for my carbs. Followed by a sync.
On my '78 GS1000, I had the pilot screw set at 1 1/2 turns. The COLORTUNE showed me a mostly yellow combustion color. Adding 1/4 turn to the pilot screw gave me a light blue burn at idle & a slightly darker blue when I advanced the throttle.
On the "big bike", the '80 GS1100E has only one adjustment on the cv carbs. The fuel mixture screw just behind the intake boot. We weren't sure if the COLORTUNE would have a practical use with the cv carb setup. But just as it did on the hotrod, I got a good slight yellow to light blue combustion color. I dialed back each mixture screw about 1 1/2 turns just to see the reaction. Sure enough, the color lost it's blue and went to yellow. I put the turns back in, and wound up adding 1/4 turn to #3 only.
Now for the CARBTUNE. Another quality tool. The best carb sync tester I've seen. No mercury, no dancing dial gages. This baby uses metal rods drawn through 4 graduated sight tubes. It's compact, & easy to set up.
The carb sync on both bikes was slightly off. The adjustment procedure was so fast & accurate, I hardly had to worry about running the fans to cool the engine. I have never had more success doing a sync. And you can ask Bruce, I have little patience in this regard. Needless to say, I'm a happy camper.
One flaw in the CARBTUNE kit is the plastic, yes plastic adapter tips to install on the inake manifold. Be prepared with some burn ointment for your fingers. I ended up using the brass rods that came with my dial gages. Two short & two long rods make installation a breeze.
Now for the bad news. These baby's are not cheap. Be prepared to perform a little CPR on your wallet. Bruce can maybe give you the link to the ebay store. Bottom line, nothing beats having professional tools & equipment to help keep the classic bikes running like they're meant to!
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