My 1600 SS1 is in for MOT today, but there is a query from the tester about emissions. Apparently the emissions are outside limits, but they don't know how to adjust them. The air filter is new (ish) and the carb, a Weber progressive twin choke is in good condition. Is this an indication that the main jets may be incorrectly sized?
the idle emissions adjustment is at the bulkhead side and uses a special hex key. however first check that all the breathers are clean, particularly the inlet to the manifold , the hose to that and especially the plastic bit that is next, the hose to the top of the engine can also clog or collapse, as well as the baffle assy in the top cover, likewise check the big hose at the other end of the cover down to bottom of the engine.
mrcheerful
Most kind. Thanks for the info.
No. Because it's easier to measure this way, the MOT test only measures emissions at idle. Your carburation can be grossly inaccurate, yet the test won't even begin to detect this.
It's a test to measure against gross wear, not accurate tuning.
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