OzVMX Forum

Clubroom => Tech Talk => Topic started by: mainline on May 30, 2010, 04:55:11 pm

Title: Colortune doohicky
Post by: mainline on May 30, 2010, 04:55:11 pm
I picked up a bike mechanics mag (seemed to be aimed at older bikes) at the newsagents yesterday and there was a piece on this Colortune diagnostic thing. Screw it into your spark hole, connect your wires back up, start the bike, and use to to tune your fuel/air mixture among a plethora of other things.

Anyone ever use them? are they any chop?

There seems to be a few on ebay, although the one in the mag was an older version.

http://cgi.ebay.com.au/Colortune-Mixture-Test-Motorbikes-Cars-14mm-Spark-Plug-/180499312173?cmd=ViewItem&pt=UK_Diagnostic_Tools_Equipment&hash=item2a0698ee2d
Title: Re: Colortune doohicky
Post by: Lozza on May 30, 2010, 05:01:44 pm
Never used one but they work OK, best on 4T engines
Title: Re: Colortune doohicky
Post by: All Things 414 on May 30, 2010, 05:08:08 pm
My Bing cataloug has an article on them. I'll try and get it on here..... :)
Title: Re: Colortune doohicky
Post by: All Things 414 on May 30, 2010, 06:05:40 pm
Having scanner probs but you can watch this in the mean-time..... ::)

http://www.youtube.com/watch?v=6hFUvQ4gaPc
Title: Re: Colortune doohicky
Post by: DR on May 30, 2010, 06:12:48 pm
I dunno, could be cause none of my bikes are what I'd call highly strung but I've always adjusted (I despise the word tuned ;)) by the good 'seat of the pants' method..if it feels right, it feels right..how can I argue with that :) obviously new model 4 strokes are hi-tech so I guess I'll wait till I own 1 before I change. Like an ol' dog eh :D
Title: Re: Colortune doohicky
Post by: mainline on May 30, 2010, 07:01:38 pm
Cheers guys, the yz125f is definately 'highly strung' so I was wondering whether one of these might be worth a shot to see if it's as good as it can be. Vandy can ride it, (the bastard ;D) but I'm struggling a bit.

The Youtube link was good, basically the thing is a 'see-through' sparkplug that you can 'read' while the motor is running?
Title: Re: Colortune doohicky
Post by: Lozza on May 30, 2010, 07:46:30 pm
FWIW your describing a peaky engine, not a highly strung one. I don't hear that many highly strung engines in VMX. The real question is what do you actualy do after you look at a blue flame? I have used Exhaust Gas Temp(EGT) as a reliable and repeatable guide to engine tuning for many years. 
Title: Re: Colortune doohicky
Post by: vandy010 on May 30, 2010, 09:49:11 pm

Cheers guys, the yz125f is definately 'highly strung' so I was wondering whether one of these might be worth a shot to see if it's as good as it can be. Vandy can ride it, (the bastard ;D) but I'm struggling a bit
and Vandy loved riding it too by the way. ;D
if your not too sure about your bikes state of tune Paul, it felt spot on to me in all aspects of the rev range. it just bogged once coming out of a turn but that was more me not being on the gas enough.
Title: Re: Colortune doohicky
Post by: DR on May 31, 2010, 12:10:50 pm
I can tune F sometimes but not as easily a regular ol' C :-X
Title: Re: Colortune doohicky
Post by: oldfart on May 31, 2010, 12:45:18 pm

Not too sure if these things will give anaccurate reading on a 2 smoker.
 
Call me old fashioned if you must .....I still do it by engine tuning by noise/feel, plus plug colour.     
Title: Re: Colortune doohicky
Post by: IT400C on May 31, 2010, 01:20:48 pm
I was actually reading a contemporary (1974) article on these things in and old magazine last night - there conclusion then was that they provide a way too lean result...

I'll try and remember to bring the article in to work tomorrow and scan it...   I think it was in a 1974 or 75 Dirt Bike magazine??
Title: Re: Colortune doohicky
Post by: IT400C on May 31, 2010, 01:22:51 pm
It must have been 1974 - just remembered it was the Dirt Bike mag with the comparo between the XL350, DT360a and Kawasaki Big Horn... 
Title: Re: Colortune doohicky
Post by: vandy010 on May 31, 2010, 02:07:43 pm
forget the colourtune doohicky Tony,
Who won the comparo?

1111
Title: Re: Colortune doohicky
Post by: IT400C on May 31, 2010, 02:11:39 pm
haha - the bloody kawasaki was best in the bush, the yamaha was best on the road, and the XL was the best boat anchor...   ;D
Title: Re: Colortune doohicky
Post by: pancho on May 31, 2010, 05:21:14 pm
I remember adds for colourtune back in the 60's i'm sure. seems to me you would need to watch the colour while under load. Could result in a stiff neck closely followed by broken bones if you don't have access to a dyno! cheers wally.
Title: Re: Colortune doohicky
Post by: Lozza on May 31, 2010, 06:57:12 pm
I remember adds for colourtune back in the 60's i'm sure. seems to me you would need to watch the colour while under load. Could result in a stiff neck closely followed by broken bones if you don't have access to a dyno! cheers wally.

Wally I cam imagine how bad my neck would be if I had a central verticle plug. :o
Title: Re: Colortune doohicky
Post by: matcho mick on May 31, 2010, 10:59:45 pm
still got my colortune,(somewhere  ::)),last used it on my velo back errr,back um,shite a long time ago ;D, :P
Title: Re: Colortune doohicky
Post by: IT400C on June 01, 2010, 10:09:44 am
The test from July 1974 Dirt Bike magazine...

(http://i374.photobucket.com/albums/oo184/IT400C/Colortune.jpg)
Title: Re: Colortune doohicky
Post by: IT400C on June 01, 2010, 10:11:50 am
Another (possibly) handy article from the same magazine...  A table with the spring rate markings for lots of the old shock types...

(http://i374.photobucket.com/albums/oo184/IT400C/Springs1.jpg)

(http://i374.photobucket.com/albums/oo184/IT400C/Springs2.jpg)

If you have the old paint markings still on the springs that is...    ::)
Title: Re: Colortune doohicky
Post by: mainline on June 01, 2010, 04:27:52 pm
that article doesn't really sell the thing does it :D

no worries, thanks anyway guys. Just seemed like an interesting bit of gear. Obviously the guy in the modern mag I was talking about has been lucky so far.
Title: Re: Colortune doohicky
Post by: Slakewell on June 03, 2010, 03:19:50 pm
I use one of these to jet my bike works a treat



(http://img683.imageshack.us/img683/456/rocket02.jpg)