anybody here use a Colortune?

Status
Not open for further replies.
maylar

maylar

VIP MEMBER
Joined
May 13, 2007
Messages
4,213
Country flag
Stock 32 mm Amals. I typically tune idle mixture by ear. Usually end up having to richen it a bit to avoid balking when blipping the throttle. I have a Colortune gizmo but I'm unsure what the "sweet spot" is. Does anyone here use one and what is your procedure? I'd like to get both plugs looking the same.
 
You connect the colortune up as a substitute for the sparkplug, then use the pilot mixture screw to get a bunsen burner blue colour in the window, swap it over to the other cylinder and repeat. If it still balks when blipping at bunsen blue then repeat but aim for similar tinges of yellow inside the bunsen blue both cylinders to show a richer mix but identical.

The need to have a rich idle to combat balking indicates the slide cutaway is too weak, if you open the throttle slightly with the pilot mix set bunsen burner blue colortune and the mixture goes light blue then that confirms.

The colortune cannot be used on an engine under load, so its restricted to tuning idle and just off idle, in itself its not going to tune out a rich looking plug if the needle jet is worn or the needle position is too high as it cannot cover this area.
 
kommando said:
The colortune cannot be used on an engine under load,
Click to expand...
+1 Absolutely correct...and primarily for this reason, a colortune is ineffective for making the adjustments best made under load.
Under load on a brake dyno, to give plugs a better cylinder temparature that will burn the (black) plug tips clean (when tuned correctly).
Under load, the cutaway and or needle taper is being tested. This does not happen at idle.
It takes some experience in doing road tests to get useful tuning information.
 
You don’t use a Colortune to make changes to a carb but rather to set the air screw correctly. For that it works great.
 
kommando said:
so its restricted to tuning idle and just off idle, in itself its not going to tune out a rich looking plug if the needle jet is worn or the needle position is too high as it cannot cover this area.
Click to expand...

swooshdave said:
You don’t use a Colortune to make changes to a carb but rather to set the air screw correctly. For that it works great.
Click to expand...

Basically the same thing said twice...

I still like a brake dyno way better as you can also sync right and left side to WAY better effect...
IMHO color tune is 95% useless. Makes for good talk on forums.
 
Whilst I bow to the superior knowledge here and elsewhere on this forum, the answers here (and in other threads too) do sometimes frustrate me...
I may be in the minority, but I don't have swathes of diagnostic equipment, a semi professional workshop et al. RE: The Colourtune.... yes.. idle performance only, but I would guess most here will aim for the OE carb settings, fixtures and fittings, renew where worn and then adjust the only thing they can, the idle mixture.
Start modifying engines then yes, a specialised leap into the dark, with many pioneers here who can light the way., but for Joe Normal with a few spanners and the wish to DIY, simple answers to simple questions, perhaps?
Stubborn nuts.... get the air wrench on it...... waddya mean, you ain't got one? The shame, the shame.... Smiles to all :)
 
Last edited:
My mate used one to set up his Ducati 860 GTS back in the day...

He seized it up in the garage in the process !!
 
Remember that the workshop manual procedure for setting idle mixture is to run the engine one cylinder at a time and tune for "most stable idle". At least with a Colortune you can run with both cylinders and have the idle speed close to where it will be. Seems like an advantage for a lowly garage tuner.

EstuaryBoy said:
I may be in the minority, but I don't have swathes of diagnostic equipment, a semi professional workshop et al.
Click to expand...

I no gots a dyno either.
 
With the advent of Idle stabilisation curves the colortune has become more relevant, I have had one for years but stopped using it as I could equal it by ear. As soon as I started to use the Boyer red box micro digital I started to use it again, I found with the idle stabilisation trying to keep the revs up I could not use ear alone so back out of the box came the colortune.
 
Gets you in the ballpark with the idle mixture, fine tune on the road to even out the pulses, add in a carbtune for off idle-mid range synchronization and then it's back to plug chops to get the mixture right (absent a dyno or exhaust sniffer)
 
maylar said:
At least with a Colortune you can run with both cylinders and have the idle speed close to where it will be. Seems like an advantage for a lowly garage tuner.
Click to expand...
A good mechanic uses the "tools including equipment on hand" to get the best results. If that means a +5% color tune, that's OK by me.

Fast Eddie said:
My mate used one to set up his Ducati 860 GTS back in the day...He seized it up in the garage in the process !!
Click to expand...
one what? brake or inertia dyno
This serves as an example of "not good" mechanic. I suspect the mate built an inferior engine/bike or did not know the proper use of the tool (dyno). Unfortunate results:mad:


acadian said:
it's back to plug chops to get the mixture right (absent a dyno or exhaust sniffer)
Click to expand...
Shot gun close maybe, but if careful, hopefully no destructive outcome! I'd agree correctly done plug chops are certainly better than ignoring black plugs for ever.
 
acadian said:
Hmmmm, I dunno Dave... I can get a 6" grouping with my .410 using birdshot, with slugs I can take the head off of a bottle :p
Click to expand...

Important to use the best tool and technique for the job. Instead of a shotgun to open a bottle of Molson Ice, try a bottle opener. Keeps the mouth from bleeding...LOL
one in the kitchen and one in the shop kitchenette next to the fridge: see below



anybody here use a Colortune?
 
Last edited:
2nd draw in the tool chest, doubles as my Triumph clutch spring adjuster :cool: (sorry to to OP for completely derailing the thread)

anybody here use a Colortune?
 
Status
Not open for further replies.

Similar threads

gpzkat
Anyone use a Gunson Colortune?
2
Replies
20
Views
627
CanukNortonNut
CanukNortonNut
Back
Top