Is a Colortune worthwhile

[William2]

I was wondering whether to invest in the Colortune spark plug tuning tool. Are they helpful in trying to get the mixture right and the engine running smoothly. My engine has Dellortos currently set up with jetting suggested for an SE spec engine. So far I have just tried synchronizing the carbs using a Synchrometer on each trumpet but the engine is still a bit lumpy.

[richardcox_lotus]

I have found it quite useful but probably best to get 2 !! I know someone who uses four !

[UAB807F]

I've found them useful, not something you can't do without but helpful. They give a clear indication of tick over mixture and when the accelerator pumps come into play as you flick the throttle.

If you know the engine is jetted correctly then I'd say you could do a similar job by careful adjustment of the idle screws, it's just quicker with a colortune. The snag is that with 1 choke/cylinder you spend more time moving it between cylinders than adjusting mixture. I bought 2 but I can see a real advantage in 4 !

Brian

[Elanconvert]

william

I have used colortune for many years and it is useful ffor basic set-up...
HOWEVER, the problem is being able to use it with the engine UNDER LOAD.......
when I set up my fuel injected imp conversion, I could get the engine running great in the garage, but on the road it was pathetic.......in the end, I swallowed my pride and spent an hour on a rolling road.......sorted!

fred

[oldchieft]

In days gone by I would set carbs by ear.

Now my hearing is less good, and I am not working on carbs very often so I am out of practice.

A Synchrometer and a Colourtune are very useful to do what once was easy but now is just plain annoying.

Jon the Chief

[elansprint71]

Four gets my vote. Back when the folks up my street ran "normal" cars it was not difficult to borrow a couple of Colortunes.

[seniorchristo]

I'm relatively new to Colortune, using it for the first time last weekend. I initially set the idle mixture using the Lotus manual which seemed to smooth things out considerably. I then more or less just verified the manual settings with the Colortune. I found Colortune simple to use with distinct changes in color as the mixture screws are turned. Im looking forward to spending more time with it.

[elancoupe]

If someone in the US is seeking one of these, I have one to sell, only used once.

[StressCraxx]

I've been using one for a long time. 4 would be nice, but you only have to set mixture once. It's a really nice tool for what it is.

I find its really useful to get the idle mixture consistent, but not set at "bunsen blue" per the instructions. There is too much stumble if you open the throttle quickly. I found that opening the mixture screw just enough to give a yellow flame works better and gives a very slightly rich 12:1 A/F ratio on my O2 sensor.

The rest of the mixture range needs to be done on a chassis dyno, particularly if you are trying to get rid of the "lean stumble". See "sidedraftcentral" on Yahoo Groups for Keith's E-Tubes and Hypojets. The driveability of my Elan with Sprint cams, bigger chokes, and tube headers is much improved.

Regards,
Dan

[Europatc]

yep. worth every penny

[alan.barker]

on my Elan Sprint i have Dellorto carbs also and the best way to balance is with "CARBTUNE".
This has four columns and each one connects to a venturi with barb connection. Dellorto carbs already have this facility. You keep the Airbox in place.
All done in 10 mins maxi and spot on .
Colourtune is only for mixture not balance
Alan

[William2]

Hi Alan, my Dellortos are DHLA 40E versions and I'm not sure that they have a venture connection as you mention. I don't suppose you have a photo, or could you explain where the venture pick off points are? Regards, William

[alan.barker]

my screwdriver is pointing to the hole where you remove the plug
good luck
Alan

[mbell]

I have a colortune, I think it's useful tool.Having to pull it in and out is a bit of a pain, especially the copper washer but its not too bad.

I use it to sanity check the idle mixture and get a basic mixture set. I don't use it to fine tune the idle to the perfect mixture mixture as previously noted often cars with webbers need to run the idle on the richer side to avoid off idle stumbles. Is a useful tool to make sure you carb adjustments are doing as expected.

[mark030358]

After reading this thread I bought one off Amazon. Been at least 30 years since I bought my first, god knows where that went.
Anyway set up this idea in about 15 minutes, yes a pain if you only have one but at least you know you are in the right ball park. Every barrel indicated rich (yellow) so adjusted to blue, then back a tad so just yellow.

Sp, all in all a useful accessory to have in the tool box.

cheers
Mark