Colortune Problems

I was a bike mech about 10 years ago and we just tuned by the color of the plug. I saw the recomendation of the colortune I thought that would be a great idea. Well anyway I finally had time to get my 650 seca back together and tried to used it but when I do I just get backfires on that cylinder, which ever one it is installed in. You can see the a light blue flame with the bright orange flash of the backfire every 2 to 3 secs. Its sparking correctly inside the plug, not up on top. With regular plugs everything is smooth and runs extreamly well(slightly lean, need to raise the jet size a notch). It just pisses me off that I spent the money on the tool and cant figure it out :?:

 

I'm no bike mech, but I did notice that while my carbs were overly lean, it tended to misfire w/ the colortune in though it would run 'ok' with the regular plug. Now that it's closer to actually being tuned (just got my YICS today, so get to do it all over again), it runs a lot better w/ the colortune in, but does occasionally miss. I'm not sure why that is.

Perhaps try enriching a bit more and see if she smooths out for you?

 

Sound like a weak spark. Check the colortune lead going into the HT lead. If that is good then remove the plug cap and check for good wire and no burns.

 

Perhaps it is inherent in the Colortune? The Colortune does add volume to the cylinder that a regular spark plug doesn't. In other words, it is a lot more hollow than a regular spark plug. Perhaps the drop in compression has something to do with it.

Maybe the colortune has a weaker spark and doesn't burn as much fuel as a regular plug, so you get some unburned fuel going through the intake.

 

Seems to be a common problem. Anybody played with the gap in a colourtune? I see know reason why the gap couldn't be adjusted to suit a particular engine similar to setting plug gaps.


Gonna run out to the shed now and check mine. :wink:

 

Well, I just went and checked mine and it is a lot closer than I set the plugs. Not sure about adjustment though, the electrode is a fair way down the tube.

Didn't measure the exact gap but if it's too close then I would expect it would fire a bit early giving a bit of backfire.


Anyone want to experiment with re gapping???

Hard to come by here so don't want to break mine but will do it if someone finds it makes a difference.

 

I doubt it is spark as it is quite a brilliant blue spark and everything is in good shape. I am thinking it is because the electrode is set so far up into the base as opposed to hanging down into the chamber. There is maybe 3/4 of an inch difference in where it is placed compared to the stock plugs. Compression might have a little bit to do with it. I wonder to, do the people with yics have the same problem? My bike doesnt have this. Just a thought