Riding with choke still on- bad?

[El Lanzo]

Hey guys, (probably wrong place but couldnt find a better place hehe)
I'm (pretty much) a noob and have only had my learners a few days. Went home riding from school at 3.30ish so it was relatively warm. I put the choke on my 2006 GN250 (only 6,000km) to warm it up while i put my gear on and just assumed it must be warm enough?, then rode off. Basically 5 minutes later, i went around a corner holding the clutch fully down and let go of the throttle and my engine just cut out and i came to an abrupt halt in the middle of an intersection :gob: To add to this, I had to hop off my bike and run it to the side of a small traffic island facing the opposite direction of traffic at which point a school bus from my school drove pass (the one i use to catch) :shit: Some nice biker drove pass though and asked if i was sweet :yes:

Basically i was there starting my engine quite a few times wondering why and saying "WTF?!". I tried driving off by just constantly revving and never letting it dropping but once again, when i came to a corner i had to let go of the throttle and held the clutch down and -engine cut- and my bike kinda skidded to a halt. So i then took off my choke which i didn't think really mattered as to if i drove with it on or not, and then it seemed fine. It idled and didnt die like before and i went home happily.

So the question is pretty much: Did riding with the choke on cause this to happen? Is it bad riding with the choke on? And if it wasn't the chokes fault, do i have a bigger problem *gulp* (It had just passed its WOF like 2 days ago when i got it) Oh and kind of unimportant one, how many times could my small wee battery start my bike up cause i did it quite a few times and was wondering if ill need to charge it?

THANKS HEAPS GUYS... I LOVE YOU

[Mom]

Riding with the clutch on is not really recommended for the reasons you experienced. Just use the choke to get the engine started and when you hear the revs starting to rise slowly push the choke back in until it is fully closed. Easy.

No harm done though really so dont sweat it. The battery may have taken a bit of a hammering during your efforts to get the bike started, but as long as all your charging circuits are working well, the battery will simply re-charge itself as you ride along.

[FruitLooPs]

Yes, the choke will do exactly that.

In short, you're running the bike very rich (too much fuel not enough air) and when you come up to idle that gets exacerbated and becomes most apparent.

It's basically drowning in fuel, you can start and rev it out and keep riding because then its getting a fair bit of air anyhow and less sensitive to small A:F imbalance. When its idle its already near the limit of turning over, so small changes to fueling will be easily noticable. My 2-stroke won't even rev out with the choke on once its a wee bit warm, bogs on accel and it'll stall if you try and idle. Then again i cant start it without choke, or i can but it'll stall - choke on leave it a min and turn it off and everythings fine.


Don't sweat it mate, your GN is fine (or as fine as one can be :devil2:). These turns where you were engaging the clutch, were you stopped or have you taken to pulling the clutch around corners? if you are, thats bad technique mate and wearing your clutch unnecessarily.

As for the skidding to a halt, the compression on 4-strokes when they stall they do sometimes lock the rear and slide to a stop (in conjunction with shitty plasticy tyres). Essentially you're in gear, but with no combustion to continue the cycle the bikes being pushed along like when someone push starts you after you dump the clutch, eventually you slow enough that the wheel will lock as the engine isn't being turned. Pulling in the clutch or sticking it in Neutral will prevent that.

[Speedracer]

Basically this is how an engine works,
it sucks in a mixture of fuel and air. If there is too much fuel (rich) then it won't run. If there is not enough fuel (lean) then it won't run (well it might but it can damage your engine and produces knocking).

The only compounding factor is that fuel only combusts properly when it is vapourised. Just like you don't see cold water produce steam, fuel doesn't vapourise as well when it's cold.

So because the fuel isn't vapourising, the engine acts like it's running lean - so you add more fuel to compensate by turning on the choke.

When the engine warms up, the fuel evapourates better, and the engine starts to run rich because it's evapourating all the fuel. If you have too much choke this can push the fuel air ratio over the edge and your bike stalls.

The reason it stalls at low revs and not high is I think because the choke adds a 'fixed' amount of fuel (not proportional to revs) - so if you use a lot of fuel by going fast the fuel-air ratio is restored. I suspect thats why your bike won't develop power in the high revs when it's cold as well.

So what you've experienced is totally normal. I usually only leave my choke on for a couple of blocks.

SNAP! hehe I'm a bit slow:second:

[notme]

....... i went around a corner holding the clutch fully down and let go of the throttle and my engine just cut out
............once again, when i came to a corner i had to let go of the throttle and held the clutch down and -engine cut- and my bike kinda skidded to a halt.

These comments worry me - are you coasting around corners? Why did you "have" to let go of the throttle? Do you mean while braking for the corner?

Have you done any formal riding courses? It's a good thing to do, if you pick a good course like the BRONZ ones you will learn about riding techniques (re this clutch in on corners thing) as well as handy hints like how and when to use the choke and how to charge the battery when necessary, how to roll start the bike etc.

[El Lanzo]

Thanks for the replies so far, will turn the choke off now hahaha.
Um im not to sure now that i think about. I generally start slowing down for the corner by changing down gears, then for the first bit of the turn i have the clutch in/down? along with my brake and then i start to accelerate again by applying the throttle and letting go off the clutch? Im not to sure though, dont think about it too much.

But yeh, im pretty sure my riding technique is bad (much like when i drive a manual car). I'm looking into taking a riding course now as this kinda scared me when the engine abruptly cut and my bike stopped in the middle of an intersection (though this was at one with lights)

[xwhatsit]

No, it does matter if you leave the choke on when you're riding. Only use it to start the engine, then once it'll idle without choke, switch it off. You're running the engine very rich (and with a high idle), so you're using heaps of fuel, won't have any power, and can foul the spark plug.

I don't know the truth of it, but I reckon idling high with a cold engine isn't particularly good for it either. At any rate I use the accelerator pumper to `tickle' the carb in lieu of using the choke.

[notme]

Good stuff matey. Try www.bronz.org.nz for the ride right course - it's near you @ Whenuapai.

I know people who coast like that in manual cars too - it's not good to do in a car and certainly not good on a bike.

The course should prove invaluable - I seem to remember some sort of (verbal only) deal that if you said you don't feel you gained anything you get yer money back? but that was many beers ago so don't take my word for it. Point is, very experienced riders go on refresher courses and benefit from it - so book the course ASAP.

It might save your life! :2thumbsup

[El Lanzo]

Yeah just wondering that, i can physically sit on my bike just revving it a bit for a few mins when i start it up as opposed to using the choke right? If so, do i just hold it at like 4,000 revs, or do i 'pump it' a bit higher let it come bak down and pump, etc etc..... Yes im a noob! Pretty sure you can do either, but just want to make sure before i go and wreck my beautiful new bike.

[doc]

Using the choke supplies a richer mixture , which means more fuel. Running with the choke on has probably caused all the lubrication to be washed off the cylinder walls. Looks like you are gunna need a rebuild before you use it again.

[xwhatsit]

Yeah just wondering that, i can physically sit on my bike just revving it a bit for a few mins when i start it up as opposed to using the choke right? If so, do i just hold it at like 4,000 revs, or do i 'pump it' a bit higher let it come bak down and pump, etc etc..... Yes im a noob! Pretty sure you can do either, but just want to make sure before i go and wreck my beautiful new bike.
Ah, if I had a GN, I'd just use the choke, start it, leave it going while you spend a minute or two putting your gear on. Then jump on, ease off the choke, see if it is ready to idle properly yet. I'd guess that the few minutes you take to get your jacket, glubs, helmet etc. is long enough for it to warm-up.

Don't rev the tits off it while it's cold. I know you want to be impatient and go and thrash it right away, but don't rush warming it up -- that's why I let it idle gently while I get my gear on.

[El Lanzo]

Ok, i think taking choke of fixed the problem. But later today (just a couple hours ago) i went riding again just so i could get use to my bike while there weren't many cars around. I started engine up fine and went driving. It idled fine when i was in first gear waiting at a light etc, but when ever i was down shifting from 3rd to 2nd or something there was a period where the engine just started revving less and less and if i didnt pump the throttle for a sec and it would cut out (again this is while i was holding the clutch down so i could shift down and was going say 20kmph?).

About 5-10 mins later to my dismay i ran out of fuel (i was unaware because the previous owners hadn't set the odometre thingy 'right' so i thought i had another 100km's to go. I must have run it bone dry because for the last 5 or 6 secs it was lyk kidn of bunny hopping much like when i was in a car when i ran outta fuel. Lucky for me, i was 20m away from a fuel station so just walked it there hahahah, and atleast this time it was dark and not many ppl saw me :jerry: I put 10$ gas in and all seemed fine, and drove it home.

I was just wondering if this second lot of engine cut outs would/could be due to the very small amount of fuel i must have been running on? cause im guessing maybe the fuel to air ration wasnt enough? haha But then why could i idle fine in first gear every time i came to a stop :S

Thanks!

[notme]

Don't worry about it - most likely you were just running out of gas. You know where the fuel selector (reserve/main) is and how and when to use it?

The cut outs when moving with the clutch in or at the lights or whatever are most likely just the fact that you had so little gas in the tank, small movements while moving around or even the lean as you put your foot down at the lights would make the fuel slosh around and a bit more be available. Another thing you would probably learn at a course is that if you are running real close to empty you can often stop and sway the bike side to side to slosh the very last of the fuel around and into the pickup part of the tank.

[YellowDog]

Hey guys, (probably wrong place but couldnt find a better place hehe)
I'm (pretty much) a noob and have only had my learners a few days. Went home riding from school at 3.30ish so it was relatively warm. I put the choke on my 2006 GN250 (only 6,000km) to warm it up while i put my gear on and just assumed it must be warm enough?, then rode off. Basically 5 minutes later, i went around a corner holding the clutch fully down and let go of the throttle and my engine just cut out and i came to an abrupt halt in the middle of an intersection :gob: To add to this, I had to hop off my bike and run it to the side of a small traffic island facing the opposite direction of traffic at which point a school bus from my school drove pass (the one i use to catch) :shit: Some nice biker drove pass though and asked if i was sweet :yes:

Basically i was there starting my engine quite a few times wondering why and saying "WTF?!". I tried driving off by just constantly revving and never letting it dropping but once again, when i came to a corner i had to let go of the throttle and held the clutch down and -engine cut- and my bike kinda skidded to a halt. So i then took off my choke which i didn't think really mattered as to if i drove with it on or not, and then it seemed fine. It idled and didnt die like before and i went home happily.

So the question is pretty much: Did riding with the choke on cause this to happen? Is it bad riding with the choke on? And if it wasn't the chokes fault, do i have a bigger problem *gulp* (It had just passed its WOF like 2 days ago when i got it) Oh and kind of unimportant one, how many times could my small wee battery start my bike up cause i did it quite a few times and was wondering if ill need to charge it?

THANKS HEAPS GUYS... I LOVE YOU
El Lanzo mate, I hope this has been a education for you:

1. Choke is to start the bike and ride until engine warms ONLY. Never ride with the choke out any longer than absolutely necessary (5 minutes).
2. Stalling the bike in a low gear, where the rear wheel locks, can be deadly; particularly on a corner or a roundabout.
3. Flooded Carbs make the engine hard to start. You need to leave it a couple of minutes before trying to re-start (without choke).
4. Don't coast around bends with the clutch held in. Gears are there to control the handling.

If you can't learn these lessons, sell your bike and get yourself a scooter.

Good luck.

[Katman]

Get yourself enrolled in a riding course - pronto.

[vagrant]

El Lanzo,
You need to have a look here.
http://www.kiwibiker.co.nz/forums/showthread.php?t=53059

[kevfromcoro]

Get yourself enrolled in a riding course - pronto.

plus one..never go round a corner with your clutch in...or anywhere with your clutch in.
as far as the choke goes...it doesnt take much to warm a bike up...time you get your gear on ..then turn it off.....
take it easy..

[aju]

The owner's manaul for my GN250 (a US market '82 model) states that the choke is bypassed when the throttle is used. The choke only modifies the A/F mixture on idle. YMMV