Hello airheads. I have a 1978 R80/7 that is running too rich (based on my senses). The plugs look classically rich, my buddy riding behind me says it smells rich and the cylinder top and heads/valves had very thick carbon buildup (I assume a symptom of running too rich).
Yes, valves have been adjusted. Yes, timing is correct. Carbs have had a “sub total” rebuild with cleaning soak and new o-rings. Diaphragms are either new or fully intact. Fuel/air mixture screws are new. The rich condition seems to be true for both cylinders. The “choke” levers close fully.
Main jet, needle jet and needle all are at factory settings for sea level where I ride. I can’t, however, tell if the needle or needle jet are worn enough to alter the air mixture or not.
Without buying new main jets in multiple sizes, new needle jets in multiple sizes and new needles, where should I start in trying to alter the fuel air mixture?
I hope that I have conveyed that I’m aware this is a complex system and there may be other factors at play but I’m specifically asking if renewing or changing main jet size, needle jet size or needle height is something I should consider.
A change in mixture or as I have experienced a drop in MPG was caused by worn main needle and jets. Did you replace these when you rebuilt the carbs? They don't show obvious signs of wear even if they are out of spec. They are not expensive and you only have to oder them off the microfiche at the dealer to get the proper ones for your bike, not much experimentation is needed for what may be a major change in things. LOL, they are not greatly expensive either to replace nor hard to. Good luck St.
Beware! I do not suffer fools gladly! St.
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