View Full Version : Exhaust Gas Analyzer??

01-08-2003, 04:58 AM
Anybody know if these gas tester/analyzers work or not?

1) Gastester Moss part #386-220. They claim it will bost performance and lower emissions.

2) There is another like item listed on LBCco's web page - an "Exhaust Gas Tester/Analyzer Digital". Made by GUNSON P/N #G-4125. LBCC states that this is the same as the 386-220.

Any advice, rumors or innuendoes welcome? images/icons/confused.gif

John Turney
01-08-2003, 02:03 PM

I've not used this particular exhaust gas tester, but I used to have one and wasn't pleased with it. What I use now is called a Color Tune (or Colour Tune), also made by Gunison. It is basically a clear spark plug so you can see the flame color in a cylinder during ignition. I started with one, alternating between #2 and #5 cylinders and then bought a second one to speed things up. You adjust the mixture until you're just between blue and yellow in flame color. I found that I can get the mixture adjusted "right on" with little fuss.

John, AH BN4

Ken G
01-08-2003, 06:00 PM
I'm glad someone else is asking these questions. I posted a question on a different forum (not the British car forum) and received rather a rude reply from someone saying I didn't know what I was talking about and implying that oxygen sensors were only relevant to modern computer-controlled engines.

However, the Gunison device presumably can only be used with the car stationary and therefore with the engine unloaded. The Stromberg OS-2 carburetor on my Rover has a number of adjustments (and rather vague instructions), and I was hoping that an oxygen sensor in the exhaust, and a meter of course, would enable me to arrive at better adjustment under real running conditions.

Has anyone experience of using an exhaust gas sensor on an antique car?

Ken G, 1925 Rover 16/50 (San Francisco)

01-15-2003, 11:49 PM
I have posted this here on some other page, but I think it's useful enough to fill up some more space:


This is how some one else fixed up their classic to have an O2 sensor. The needles are for a Hitachi SU, but it still applies.

For more SU info go here:

I know it isn't going to help Ken and his Strombergs, but there are alot of SU owners here too. I'd suggest looking for Triumph performance pages to get more Stromberg tuning info.