Spark plugs

Those colour tunes along with most compression testers etc come the shortest reach threads of the plug type they are intended for.
If they came with long reach threads there's bound to a few users who screw them into a short reach hole and damage a valve or something.
Idiot proofing is the usual term..

zed1015 wrote: Those colour tunes along with most compression testers etc come the shortest reach threads of the plug type they are intended for.
If they came with long reach threads there's bound to a few users who screw them into a short reach hole and damage a valve or something.
Idiot proofing is the usual term..

Is colortuner a good tool for tuning?

gordone wrote:

zed1015 wrote: Those colour tunes along with most compression testers etc come the shortest reach threads of the plug type they are intended for.
If they came with long reach threads there's bound to a few users who screw them into a short reach hole and damage a valve or something.
Idiot proofing is the usual term..

Is colortuner a good tool for tuning?

Some people love them..
I don't.
They can give misleading readings with modern fuel and weren't that great before.
Wasted my time using them a few times back in the day and always had to correct the fueling to actually run correctly once out on the road and under load..
Ok I suppose to get somewhere in the ballpark if the carbs are miles out but don't take the results as gospel and you will get just as close following normal adjustment procedure.

I don't use my colour tunes, I have two, 1 has a long reach thread with spacer to convert to short reach, the other has the standard short thread.

Warren3200gt wrote: All sounds like a lot of faffing to me. Why not just use a reverse action thread chaser. Goes through the plug hole, expand it and unscrew it. It brings any cut material out with it and nothing can drop into the cylinder as the expander plate is the internal thread size.

www.amazon.co.uk/Sealey-MS003-Reverse-Ac...Thread/dp/B0086306NO

Thanks. I just ordered one (looks rebranded) from amazon canada: www.amazon.ca/Powerbuilt-640811-Back-Tap...id=1605290934&sr=8-2

Seems a lot safer.

gordone wrote: Is colortuner a good tool for tuning?

I have one, and I thought it was useful. I have only used it for adjusting the idle air screws. I'm not sure how one might use it for anything other than adjusting idle mixture.

I thought it was useful to be able to look at the color of the spark as well as listen to the idle speed change as I adjusted the air screws. And I thought it was useful to set each cylinder to the same color, since I could see the combustion color change without a very noticeable difference in the engine speed or sound.

Also, I noticed that the #3 cylinder was occasionally misfiring at idle. I could hear the idle speed drop very slightly at the same time I noticed the spark going out. I hadn't noticed the stumble before I watched the misfire through the colourtune window, and I don't think I would have been able to pinpoint which cylinder was having the issue without it. I never got around to tracking down that specific issue, but it exposed the issue very clearly.

You would think owning a 40+ year old motorcycle that there would be much better use of time than farting around with a colourtune!

Anyway, must go now as I'm indexing the sparkplug on my lawnmower.

Mc Tavish wrote: You would think owning a 40+ year old motorcycle that there would be much better use of time than farting around with a colourtune!

Anyway, must go now as I'm indexing the sparkplug on my lawnmower.

Make sure you side gap it too to expose the maximum amount of spark to the mix.

DOHC wrote:

gordone wrote: Is colortuner a good tool for tuning?

I have one, and I thought it was useful. I have only used it for adjusting the idle air screws. I'm not sure how one might use it for anything other than adjusting idle mixture.

I thought it was useful to be able to look at the color of the spark as well as listen to the idle speed change as I adjusted the air screws. And I thought it was useful to set each cylinder to the same color, since I could see the combustion color change without a very noticeable difference in the engine speed or sound.

Also, I noticed that the #3 cylinder was occasionally misfiring at idle. I could hear the idle speed drop very slightly at the same time I noticed the spark going out. I hadn't noticed the stumble before I watched the misfire through the colourtune window, and I don't think I would have been able to pinpoint which cylinder was having the issue without it. I never got around to tracking down that specific issue, but it exposed the issue very clearly.

I understand, I have one I have not used, maybe I shall try it when the spring comes to adjust the idle mix. I was thinking the temperature on the colourtune was off compare to the sparkplug maybe..,

Thank for feedback all.