As anybody out there used the gunson colortune, if so how did you get on with it. I've got a 1600 twin port bay and thinking about getting one, the principle of being able to see the actual colour of combustion is a good idea, but is it easy enough to use.
I've used one on my MG and it was really useful for getting the mixture right across the twin SU's where there are a load of variables and adjustments needed to get things properly tuned. I did try on my 1600tp but I gave up as I couldn't get it to fit in such a way that I could see down the tube to the plug. May well be something I was doing wrong..!
looking at the kit on-line that tube now seems to have a mirror on the opposite end to the plug so you can see down into the extension tube and see the plug. did you have this
I did have this but I still struggled to get it to an angle that I could see. It was a while ago though and I can't remember exactly what the problem was.
thanks a lot for the reply mate, I may still get one and try it I've found one for as little as £21 on a Leyland mini site (new one)
Have used one on my MG which sorted out the twin su's but I think there would be a fitting problem on our engines but perhaps if a rubber tube was used to jam the plug into it, might allow fitting the check plug in at a angle! There is also a thin copper sealing ring on the colourtune plug that just falls off so that's a added problem when fitting or removing.
I use two on my bay- when it were a single carb, I just used a CO meter, but with twins you can never tell if one's too lean and one's too rich, so one colortune on each side is brilliant (you can get away with one, just means that you can adjust both carbs on the fly). I check that with the CO meter to check overall mixture and just make sure the colour is the same across both. I have used it with and without the mirror/tube, the LHS one is easy to see just by sticking your head in, but the RHS is a bit of a reach if you don't use the mirror. I can just about manage it with the engine running but I do get pretty close to the dynamo, certainly not a good idea to wear loose clothing if you're doing that! I would definitely recommend it over tuning by ear, which is a bit of a clumsy way of doing things. But if you're running a single carb, a Gunson CO meter can be had second hand relatively cheap and gives you a number that you can compare to factory specs, which can be invaluable. If you go colortune, just make sure you keep the glass clean on the "spark plug" as it'll soot up over time and that'll change how the flame looks. Carb cleaner spray does a good job of that. Oh, the copper ring... pop a blob of grease on the glass spark plug to hold it on. If it comes off on removal, a pair of long nose pliers or a pencil should get it out. Always has for me.
Its a start for setting up. But the difference in mixture between an engine running fast in neutral and doing the same rpm under load is massive. Maybe try a small colour TV camera or one of those 5 metre USB bore cameras pointing at it so you can see it when somebody drives the bus, instead of a mirror.
I use one on my type 4 engine. A little bit fiddly but well worth the effort for how often you do it. Mine has the tube with mirror on the end. It’s amazing to see the flame change colour as you alter the mixture screw. I use a long rubber pipe pushed over the plug to get it started .
I use one on my type 4 engine had one since they first came out but don't forget to do all the basics first and of course airflow balance
Had a play with one i got of fleabay last week. Awkward to use due to the tin etc but quite a useful gadget. The plug with the glass window is ok but the rest of the kit is so cheaply made & poor quality. Not as accurate as setting with a lambda sensor or CO meter but good for checking individual cylinders with twin carbs Worth superglueing the copper washer to the plug to avoid it dropping off.
