25-07-14, 11:02 AM
(25-07-14, 10:37 AM)His Dudeness link Wrote: That's good news that you got her sorted. I think cracked inlet manifolds would be more likely to lean out the mixture rather than richen it. The engine creates a vacuum to suck in the air fuel mixture from the carbs so if you've got cracked inlet manifolds it would be sucking in extra air through the cracks rather than letting air out so it would lean out the mixture. Sooty plugs might suggest your air filter could be a bit blocked so it would be causing a slightly richer mixture.
yes, thats what the logic would point to. However, I had sooty plugs, clean (new) air filter. So replaced the plugs and ran it for a month - still sooty. Eventually diagnosed as cracked (hairline but cracked) rubbers so replaced this then the plugs. all fine now.