Auto choke, can it be manually turned off ? CBF125

[Paul2129]

I do lots of stop/start around town and get frustrated with the over-keen choke that comes on each time you leave the bike for a few minutes to cool. It's annoying because the revs hang until it turns itself off.
Does anyone know how I can manually turn this off, or somehow trick the bike into thinking its warm ?
I have a CG125 which only ever needs choke in deepest winter, I don't know why the CBF needs it during a hot summer ?

Any suggestions appreciated !

Edit : it's probably not technically a choke because it's fuel injection, so how does the ECU (or whatever) work out that a sufficient temperature has been reached to alter fueling and tickover back to the settings for a hot engine ?

[clancy]

How long are you leaving it between short trips etc?

Once up to temperature, you could leave a bike for 4-5 hours in summer and it wouldn't need the choke on to start up again

If it's always using the choke on start up it sounds like somethings up
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KLX 300r

[Paul2129]

I'm sure there's nothing wrong with it, but it's just overly keen, and seems to come on after the bike is left for an hour or so, even in summer

[Itchy]

Er its a CBF125 its fuel injected its NOT choke, its a fast start up idle. They all do that until the CDI detects that it is up to temp.

It sounds wasteful on fuel since on my old carb CBR600 I could turn off the choke within seconds of it firing up, but thats FI for you.
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Spain 2008France 2007Big one 2009 We all die. The goal isn't to live forever, the goal is to create something that will. In the end, your life will flash before your eyes. Make sure it is worth watching.

[blurredman]

Do FI on bikes use the old thermal valve/melting wax still?
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CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S, 1979 MZ TS150.
Current: 1973 MZ ES250/2 - 18k, 1979 Suzuki TS185ER - 10k, 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (295cc) - 40k, 1989 MZ ETZ251 - 51k.

[The Shaggy D.A.]

Sell the CBF, use the CG?
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Currently : Royal Enfield 350 Meteor
Previously : CB100N > CB250RS > XJ900F > GT550 > GPZ750R/1000RX > AJS M16 > R100RT > Bullet 500 > CB500 > LS650P > Bullet Electra X & YBR125 > Bullet 350 "Superstar" & YBR125 Custom > Royal Enfield Classic 500 Despatch Limited Edition (28 of 200) & CB Two-Fifty Nighthawk > ER5

[candymut]

If the bike is fuel injection then you are stuck with it.
The fuel injection is automated by your ECU and the sensor needs to know what the temp is of the engine oil the air intake and the CO sensor from your cat (if one is fitted) and water temp if the bike is water cooled.

The ECU then calculates the fuel/air mixture and also the timing of the spark given what the sensor's are telling the machine's ECU.
Some mess around with the water/oil cooler sensor but all this will do is make your bike run to lean and your ECU will stop the bike or worse your bike will die on you on the road causing you to loose power (not recommended).

Carb bikes are mechanical in nature so have a choke but the days of the carb (even though I think they are a lot smoother) are long gone.

ALL new bikes need to conform to EU emission controls ..its the way it is sorry.
PS...a CG125 will only need to be filled up once in a blue moon I will have thought as they do around 70/100 MPG I will imagine but you need to consider that a warmed up engine will last longer than a cold engine running on standard mixture , I hate to see people hammering the throttle on cold bikes and smile when the rings go pop ..well I am an old git

[Itchy]

[candymut]

well you could get a remap of the ECU, but I doubt it, my CBR gets up to temp and the high revs stop after about 250metres anyway. On my way home it stops within 150 metres.[/quote]

The days of the carb are numbered the one son the road today are the ones that were pre injection.

Injection is reliable but costly to put right but that's the way things are.
Re mapping normally makes the bike faster but this will have some impact on your insurance if they find out after a collision who knows.

I like fuel injection as it is reliable and no flooding and less parts but one day injection will be as smooth as the old carb but by them we will all be on electric bikes

My GSX 1250FA2 is always just over the 1k mark on the rev counter even when cold it never changes unless I rev it (pointing that out as some one will say something funny if I did not mention that

It has been some time from when I was on a 125 though but I use to have the old CG125 and that was a single carb and lasted me 5 years until it fell to bits as using it for work every day with little maintenance apart from tyres and chains etc and oil. and once I had to change the cam chain and tensioner .

[Itchy]

[Paul2129]

Thanks guys, I guess I was just hoping that there was a straightforward way of adding some manual ability to turn the choke off, now I understand that it's a lot more technical than that.
Out of these two little bike, the CG is more agricultural but is a lot better made, and infinitely more rust resistant than the Indian made CBF. I like the CBF's 150mpg on my typical town riding vs. the CG's 115mpg, but the CBF build quality and reliability is awful. Both bikes will be staying, but ultimately the CBF will probably be sold first, the CG doesn't owe me anything