Expected hydrocarbon level with CO at 4%.

[FresnoBob]

I borrowed a Snap On CO meter from a friend and used it to calibrate my Innovate Motorsports A/F meter and fine tune by fuel mixture.  Using the recommended level of 4% CO, I found the hydrocarbon level was 439.  Is this reasonable or do I have a further ignition issue?  BTW - my Innovate meter was reading 12.7 when the CO was 4%. 

[rwmastel]

Bob,
This is off topic, and I don't mean to redirect your thread.  We have very similar taste in cars!  I have a 1966 230SL Euro Auto (12-018381) and I would love to have a C43 (not cabrio).  For now, I'll plod around in my old E300D.   

[stickandrudderman]

There's nothing much to worry about there. HC are at the top end of acceptable but I wouldn't go chasing it.

[FresnoBob]

Well Rodd, my 230 SL is a bit of a Frankencar as it has a new 250 motor, 280 hubcaps and taillights and a US version Becker radio.  The C43 is an absolute blast to drive, particularly with the 4 wheel drive.