How Long On The Choke?

[yammafan]

I’ve heard a few people mention that once I start my bike on the choke, to take it off the choke as soon as possible. Is this right? Does it matter how long I run it on the choke? Is there a better way to start a 2-stroke?

I’ve never had any trouble in the past but just wanted to make sure I was doing the best for the bike.

As you can probably tell I’m quite new to trials!

[twinshockdude]

turn the choke off as soon as the bike will run without it

if you leave it on you will oil the spark plug

[yammafan]

Thanks twinshockdude, will do.

[old trials fanatic]

turn the choke off as soon as the bike will run without it

if you leave it on you will oil the spark plug

not good for the motor not just plug oiling but on a four stroke can almost eliminate the film of oil that protects the motor when it needs it most on cold start up.

[ham2]

Once started, I use this procedure ( I got it from NASA ):-

One-elephant, two-elephant.....all the way up to seven then lower the choke and rev the bike a little...have I got OCD?

[neilh]

once its running i knock the choke off straight away. if it tries to stall i keep it running with some hollywood style throttle revving

[jse]

not good for the motor not just plug oiling but on a four stroke can almost eliminate the film of oil that protects the motor when it needs it most on cold start up.

I shut off the choke as soon as the engine starts for the same reason. I use very light throttle "blips" to keep the bike running at low RPMs until it can idle on it's own (usually fairly quickly if the jetting is correct). Initial start-up can be really hard on an engine as the clearances (piston/cylinder) are very tight and any over-revving will cause excessive wear and in unusual circumstances, cold-seizure. On my Dellorto, I drill the starter jet out to #80 (.031") and have no problems with start-up in any weather.

Jon

[mung]

I would agree with the get off the choke as soon as possible on a four stroke but would disagree on a two stroke.The choke lets in additional fuel to make it easier to start but in doing that it also allows more oil into the motor as it is part of the mix.A good percentage of a motors wear comes at cold start up.To have more oil at this critical time could not hurt.At 40 degrees [F] the motor sure seems to run smoother,quicker if I use the choke for 20 seconds then hold idle up with the throttle.So without the choke, really you are forcing a motor to run lean,which does not help a motor that has very tight piston and ring clearance. Of course I could be all wet.

Edited April 8, 2013 by mung

[pindie]

Open the throttle and tape it wide open. Choke on and kick. As soon as it fires and is running smoothly turn of the choke.

and allow the engine to warm up nicely.

The taping the throttle open is a joke - don't do this!

[0007]

Pindie that was a dumb comment..........everyone knows you just take the slide out

You could also just kick it til the internal friction has warmed the motor and then it would start with no choke

[shyted]

This is a subject that you need to understand . I've had two bikes since 1976 that have fouled plugs religiously . An RC 30 and a BSA Bantam . None since the RC 30 and that was down to trying to ride it in the realms of sanity .

A choke ( fuel enrichment device ) alters the air fuel ratio either by supplying more fuel or restricting air flow .

The point of it is to warm the engine up , so fuel sticking to the induction tract is compensated for, until , eventually, normal atomisation is beginning to take place. Let it idle for a little while until the exhaust smoke starts to heat up . That means the fuel is starting to be used efficiently and the temperature is starting to get passed on from the combustion chamber , to the metal . use a small amount of steady rev's until the bike runs without choke .

I hate it when i see people fire engines up and drive off straight away . Worse still sit there revving the tits off them as soon as they start .That's just me , and thats why i had a Peugeot 405 diesel with 425000 miles on the clock with the original engine .

Hope this put's some understanding your way .

Ted .

[pindie]

I too had an RC 30. Best bike I have ever owned. Was a pig to set up the flatslide carbs nicely though. It used to cough when they were off but when they were "on" it was the silkiest throttle you have ever twisted. Bring back carbed sport bikes!

[0007]

LOL, ride an R1

After that try and convince me we still need carbed sport bikes

But having said that, sometimes character is hard to replace

[shyted]

0007 try an R1 up to 2002 because they were carbed , you will be shocked how smooth and gutsy they are , especially compared to injected bikes of the same era . David Jeffries demolished the average speed lap on the Isle of man on a carbed R1 . After that the injected GSXR 1000 . What makes you think ,i for one , haven't ridden an R1 of both type's ? There are reasons why the RC 30 commands a kings ransom for resale , as even an 0w01 of the same vintage commands less than half the price of the Honda , which is also a 750 . So what i suggest , if you haven't tried one , get a ride on an RC30 and then you too can laugh out loud when you get off it while you stop shacking with adrenalin at how insane that little bike has just carved your favorite road to bits ,because the noise alone will give you a stiffy for a week as it snarls like no other invention you've ever heard on this earth ! You will convince yourself that there's room for both.By the way think the R1s are great bikes ! Not to lose the thread , even injected bikes have a fuel enrichment devise ( system ) as well .

Best regards Shy T

Edited April 26, 2013 by shyted