Failed Emissions, Now What?

My 1100 failed the yearly emissions test, twice this time, so I can't get the license renewed this year. They require it pass HC and CO at idle and the HC (unburned hydrocarbons) was slightly too high. It has to pass with the same test results as a new bike, 5.50% CO and 1800 PPM HC but since it's not getting any younger so that gets harder to do every year and mine read 2249 PPM, just a bit over. It's always hard to pass at idle since the idle mixture screws have to be adjusted just right so it's as lean as possible without missing, which is just a matter of 1/4 turn either way. If it's slightly too rich the CO will be too high but if it's slightly too lean and misses the HC will be way too high but I have always been able to get it set correct with a Color Tune and double check with an exhaust gas analyzer. There's not even a test station in my county so even though I setup the mixture just right at home the carbs don't have temperature compensation so it's usually a bit off after I drive all the way over to the test station and I might still fail the first time but after I see the test results and tweak it a bit I can usually go back the next day and pass. This time when the HC was too high I figured it must be missing slightly so I changed the plugs and reset the idle mixture screws using the Color Tune. There was no evidence of missing and it was running fine but when I went back for a second test it still failed the same as before!
My Exhaust Gas analyzer doesn't measure HC, only CO, so I'm not sure what to do at this point. The engine has 70K miles and runs fine but doesn't idle very smoothly at slow speeds but it doesn't seem to be missing either. I'm pretty sure the cam chain needs to be replaced and the valves adjusted. Also it burns a little oil, not enough to smoke or foul the plugs but the level does fall after high speed driving so it may need rings. I wonder if burning oil would make the HC level read too high? It's always burned some oil but not at idle. Interesting the precondition run they made me do at 2500 RPMs produced an HC reading of only 500 PPM so the problem seems to be occurring only at idle. Does anyone have any experience with fixing high HC levels who could offer some advice?
If I tell them it normally idles at 2500 I don't think they would buy it.

 

Yes Oil is part of the HC mix. Few oilburners pass Testings.
Sounds like Retirement time given the costs of a rebuild that will pass testing more than once.

 

Here in TX there is an age limit to emission testing. My 81 XJ only needs the standard safety check to pass inspection now.

"Emissions counties in the DFW and Houston/Galveston areas
In conjunction with the annual safety inspection all gasoline powered vehicles from 2 through 24 years old which are registered or primarily operated in emissions counties will be emissions tested."

http://www.txdps.state.tx.us/vi/inspect ... m_insp.asp

 

We had emissions testing here for awhile (at least for cars). If the car was more than 10 years old it was exempt. If you failed you had to either re-take and pass or show a receipt for $50 in repairs to attempt to fix the problem.

Now I'll tell a funny story and a confession. I change oil religiously. All other maintenance I tend to put off until something turns up. I've been known to use a set of spark plugs until the electrodes are mostly gone.

Anyhow, I had a pickup truck that the only service I did was oil changes 4 times a year. Every year when it was time for my emissions test my sphincter would clench. Every year it had LESS emissions. It was a real puzzler for me.

Then one day the tailpipe fell off. Turns out the pipe had been rusting through at the longitudinal seam. So I had a 1/4" X 6' air inlet going from the muffler to just before the pipe came out under the fender. I guess each year more rusted out and I got more fresh air in.

By then we didn't have the emissions checks anymore so I didn't have to worry about failing because my tailpipe didn't have holes.