"Stuart" wrote in message news: snipped-for-privacy@y41g2000cwy.googlegroups.com... : hi - wonder if you can help me - My Landy SeriesIII lightweight has : just failed on MOT, but emmissions only. : : MOT station have told me that Hydrocarbons are to high: : : should be
First, check the ignition timing and adjust if necessary - if the timing is out there's no point trying to adjust the carb. If the fuel mixture is very lean this can cause high HC content due to incomplete burn. Easy carb to adjust, there is an idle mixture screw on the side of the carb nearest the engine, if memory serves me right it's in to enrichen, out to weaken. Most mixture screws have a spring on them to allegedly prevent moving due to vibration, but as things get older and weaker it's possible the screw has unscrewed itself a little due to engine vibration. Once set correctly, a spot of paint applied to it will at least let you see if it's moving of its own accord. But check the timing first. Badger.
Ok, so for the short-term, adjust the carb (after checking the ignition timing!) and get it throught he MOT. Then, contact the British Motor Industry Heritage Trust with all details (chassis no; engine no; consignment no. etc etc) and get proof of age from them. DVLA will then ammend the V5C and next years MOT will be a breeze. Even if you only get proof of the age of the engine to within a few years, there is a clause in the MOT that allows for the retro-fitting of an older engine and the testing of the emissions to the age of the engine, not the vehicle, if the engine is older than the vehicle. So if they (BMIHT) said the engine was produced between 1973 and 76, the MOT tester (when presented with the proof, i.e. the BMIHT letter) would have to test it as a 1976 engine for the purposes of emissions, for example. Not a lot of people know about that clause in the testers manual. I've put a range-rover based (late classic) hybrid through a test on visual only, due to the engine number! Badger.
On or around 23 Jun 2006 09:55:56 -0700, "Stuart" enlightened us thusly:
what year is it? the HC rules only come into play for late SIIIs.
lean mixture can lead to high HC so that may well be your problem. I'd suspect carb wear or air leaks, or simply incorrect carb setting. adjust the idle mixture, then get it checked again - if the HC is still high then it could be burning oil.
Thats the beauty of an oldie isn't it, you can get away with murder. I even found some leaded petrol to put in mine the other day, but at that price I won't be doing it too often.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.