What happens when the choke is left on too long on a motorcycle?

Answer 1

In my Yamaha Manual it says, "Do not use the choke for more then 3 minutes as the exhaust pipe may discolour from excessive heat. Also, longer use of the choke will cause afterburning". I forgot to turn mine off for a 30 minute ride. I felt really dumb afterwords. My exhaust pip did not dicolour but my engine feels different, it might just be in my head. RESPONSE Using the choke on any motorcycle changes the fuel and air mixture. No choke means that you have the "correct" ratio of fuel to air, which will give you the highest fuel efficiency and the least amount of wear and tear on the engine, as well as correct lubrication from the engine oil. Using a full choke means more fuel and less air are getting to the engine, which causes an engine to wear faster. Oil runs thinner and will not lubricate as well. As a result, the motorcycle is less fuel efficient and runs hotter. Leaving a full choke on for three minutes or less is fine to get the engine warm, but once the engine is warm, there should be no need for the choke. If your carburetor is dirty, and you are not usng the choke, the engine may die. But, this is not a good excuse to keep the choke on. You are hurting your engine, and not helping to solve any carburetor problems. In this case, you should have the carburetor cleaned, jetted, and synced. This should solve your "choke" problem. Also, fuel injection motorcycles do not have a choke.