Mixture

[mobylette]

I'm still trying to get the mixture right. I only do short journeys, and recently after having to move the car in and out of the garage on choke, it fouled a plug. It did clear after a short run, but on checking the plugs they were very sooty. The engine (recently rebuilt) is running an HS4 carb on an alloy inlet manifold, hot spot removed, so does take longer to warm hence longer on choke. I had NGK BP6ES fitted, so I decided to try the hotter BP5ES. I have been for a 5 mile run, and the nose of the plug looks a good colour to me, what do you think? Still a bit sooty around the rim. The engine seemed to warm up faster/choke in earlier but I might be imagining that.

[svenedin]

Plug looks ok to me. What does “hot spot removed” mean? Short journeys in colder weather are never ideal with these engines. What thermostat do you have fitted and is it working properly? If it’s stuck partially open it will take ages for the engine to heat up. Also check plug gaps and the overall condition of the ignition system.


Stephen