+- Austinsevenfriends (https://www.austinsevenfriends.co.uk/forum)
+-- Forum: Austin Seven Friends Forum (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=1)
+--- Forum: Forum chat... (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=14)
+--- Thread: C O Readings (/showthread.php?tid=2818)
C O Readings - rubyman - 20-05-2019
I know ARR Ruby's run a bit rich, but I would like to know what members A7's run at, my ARR Ruby runs at 2.7 - 2.8 c o its a good job it is mot exempt as it wouldn't pass to days test.
26VA carb all jets cleaned, new carb & manifold gaskets, all compression's 110, plugs NGK B6HS, carb air screw doesn't make much difference to c o
what do you think lads
Graham in Sheffield
RE: C O Readings - David Stepney - 20-05-2019
Graham,
For vehicles first used before 1st August 1975, there are no emission requirements. Provided that there is no dense blue or clearly discernible black smoke coming from the exhaust pipe, it will pass an MOT.
Seven's like to run a bit rich. If I get mine to run with a nice blue flame using the Colortune, it has flat spots all over the place. I would have thought that a CO content of 2.7 to 2.8% is good. For cars made between 1975 and 1986, the maximum permissible CO limit is 4.5%.
RE: C O Readings - JonE - 20-05-2019
my carb air screw started making a huge difference, with an obvious 'right' position, when I replace the DK distributor for an accuspark unit. I don't know whether that would be the right, or an improved, setting if the accuspark was changed back to an original distributor (presumably with more wear).
RE: C O Readings - Graham Honnor - 20-05-2019
If your plugs are sooting up a bit I would change to a slightly hotter plug, namely a B5HS.
I did this a few years ago and have never looked back.