Co testing

[sxl01]

Hi all, I've been given a Gunson gas tester by a retired mechanic. It has a switch showing 2,4,5,6 cylinders, would this be suitable for the Stag or will I need a tester suitable for 8 cylinders, ta

[Motorsport Micky]

I think the Stag will blow it's mind. Because of the relatively crude emissions control of our engines other than at tickover you may find it difficult to use.

Micky

[sxl01]

Micky, thanks for your reply. When I went for an MOT the tester said it was running rich, he could smell it, he seen the twin pipes and didn't bother with the test probe. It failed on hand brake and NS beam setting. When I got home I checked the adjustments on the carbs and for rich/weakness by lifting the pistons and they tested aok but would like to test the CO if possible.

[redstag]

No idea how good these machines are but I don't think the cylinders switch will be relevant for measuring CO.
I think it may have a function for measuring dwell.

Pete

[wilf]

I have one of these, and the readings wander all over the pace, and do that on pretty much any car I have tried it on.

The switch for number of cylinders is used to get correct tacho/dwell readings if it ahs that facility, doesn't affect CO IIRC.

[dasadrew]

I have one of these, and the readings wander all over the pace, and do that on pretty much any car I have tried it on....

Ditto!

I've had a Gunson's one kicking around in its box for years now. I found that the results were simply unrepeatable. An electronics sparky at work said he'd have a look at it and reported back that the principle was fine, but the components used drifted as the measuring was taking place and with temperature etc. He said it would be easy to replace those components with more stable IC's or whatever (digital vs. analogue components?) and took it home. With great sadness I have to report that he died shortly after from skin cancer (RIP) and his widow gave me back the box of bits some time later.

Is there not an electronics sparky on the forum who could follow through on my deceased colleagues's ideas? Could maybe be a mod which we could all apply to a Gunson Tester.

Drew

[sxl01]

Thanks guys for all your input, much appreciated, ta