My buddies’ TL 1000 has a choke setting for starting it, even though it is fuel injected. Why?
It’s a Cold Idle switch. It richens up the fuel so the bike starts and runs better in cold weather. Basically like a choke for a carbed motor, but for FI.
No. I meant, why does this bike have it when there are millions of cars, even high performance FI cars, that don’t have a choke? I haven’t asked him if it starts without the choke… maybe it’s there just for emergencies? (I would think that if the bike needed a choke setting, the computer would take care of that upon starting)
Nope. Not emergancy’s, could work though.
Moder cars DO have a choke, it’s just not called that anymore. It’s call an ‘Idle Air Sensor’. Basically, when the engine is in open loop the sensor plugs a hole in the throttle body letting less air in (more fuel to air ratio). When it gets warm (closed loop), the sensor unplugs the hole letting the appropriate amount of air into engine. With the bike, it may be an actual choke plate 'cuz it’s cheaper to make.
My Yamaha XJ600 Seca II is carburetted. It doesn’t have a choke, though; but a “cold idle switch” that works in the way WhiteyFoo describes:
So, the answer is “It’s cheaper”? It’s cheaper to do this manually, rather than have an idle air sensor? No other reason?
My question wasn’t about how the switch works but why it’s there on a fuel injected engine… I thought chokes were only needed on a carbureted engine until I saw this bike. Thanks for taking the time to explain the choke to me though, it’s good the people on this board are so thorough.
F1 cars and other engines used for high performance purposes do not need a choke. Even when I drove jalopies at my local short track, one of the first things we did to improve performance was remove the choke plate. F1, CART, IRL, and the top 3 NASCAR division all use electric heaters to warm liquids such as oil and engine coolant to near operating temperature prior to the engine even being started for the race. And as with street cars, once an engine has warmed up, the choke is not needed anymore. The only type of racing engine that is choked to start it is the engines used in Top Fuel and Funny Cars of the NHRA. These engines do not have any coolant in them and with 18 quarts of 0 weight oil for lubrication, the oil does not need to be heated. If you watch one being started, someone shoots a couple squirts of gasoline into the butterfly housing then that person will hold the butterflies shut till the engine fires.
It’s smaller. Everything on a bike must be small, and unnecessary things are not used. This is why pedal starters were on motorcycles long after cars had gone electric. This is why motorcycles don’t have reverse gear. This is why (well, one reason why) many motorcycles don’t have fuel pumps, water-cooling, or automatic chokes.
I would think there would be other reasons why motorcycles don’t have a reverse gear. I can’t imagine handling a bike in reverse, for example.
So, the air sensor takes up a lot of space? I don’t know about sensors or FI systems but it seems like that would be a small part, possibly smaller than the manual mechanism on his bike…
You are probably right, I am just wondering specifically.
Jillgat, having reverse on a bike would be soooo handy, and loads of fun too!
Well some bikes do have fuel pumps (try any fuel injected bike), many are water cooled. As far as an automatic choke goes, a temp sensor for the engine (which probably already exists on the fuel injection system, and a different program is all that is required to have a “choke” or cold start program. (just inconvience a few electrons)
My personal WAG is that the choke setting is a high idle setting that allows the engine to warm up before driving off.