Bike won't start with choke on


18 replies to this topic
  • CanadianWR450

Posted April 20, 2009 - 01:02 PM

#1

So, most have probably seen that I have rebuilt the top end on my bike, and added some goodies, and also had my starter die at the same time.

So now learning how to kick.

Here is what I have figured out:
- Bike does not like to start with the choke on
- With choke off, and a couple of twists, it's sooo close to going. it will catch and fire for a few revolutions, then die.
- twist up the idle screw a turn or two, no choke, bike fires up.
- It's still only about 45-45 degrees here.

What is this a sign of?

One thing I forgot to mention, I did the "How to check your pilot circut" test, and it checked out, srewd in fuel screw until bike sharted to drop rpm's, and then out until it smothed out, and it was about 1.5 turns





Once bike is warm, it starts like a dream. One kick
It runs awsome, no bog, no stutter, monster power, idles smoth, almost no decel pop.

Jets and needle/positions are stock, except a 168 main.
Adjustable fuel screw is about 1 3/4 turns out, and I have adjusted it so the bike runs awsome.

Has hot cams, FMF Ti-Powercore, airbox cut outs, and it's a 04 Canadian bike, so no AIS, no short throttle screw, and grey wire is cut.

I'm going to try this out in the Jetting forum as well.

  • Krannie McKranface

Posted April 21, 2009 - 03:39 AM

#2

It sounds like it is jetted and running normal to me. I have never used my choke in any weather. Just two twists when it's above 60, and three when it's below.

  • jhmotard

Posted April 21, 2009 - 04:35 AM

#3

i would go up on the pilot jet, assuming by your name its at least an 03 model.....i think they come stock with a 45pilot, try a 48 and adjust fuel screw accordingly. remember to test that while the bike is at full operating temperature

  • redhurricane

Posted April 21, 2009 - 09:55 AM

#4

Choke circuit dirty??

If the bike runs properly (subjective) when warm, is the choke circuit what's at fault since the rest are operating corrrectly?

  • CanadianWR450

Posted April 21, 2009 - 10:10 AM

#5

I picked up a new spark plug, and I'm going to go out and play with it...

At this point, I'm just trying to figure out if I simply don't know how to kick start this bike yet, and just need to figure out the proper "drill" for it, or if I actually have a problem, If I don't get anywhere, I'll pull the carb, and clean everything/double check everything.

I'm also wondering if my "problem" will go away with warmer weather...

  • William1

Posted April 21, 2009 - 12:16 PM

#6

Make sure..... the starter jet is in the carb......... S/B a #68 or #72

  • CanadianWR450

Posted April 21, 2009 - 01:47 PM

#7

Make sure..... the starter jet is in the carb......... S/B a #68 or #72


Ok, silly question time, although I'm SURE the starter jet is in there, lets just pretend it's not.....

Wouldn't it have issues starting when warm as well?

  • jhmotard

Posted April 22, 2009 - 05:24 AM

#8

i'm 99% sure on this....
because you opened up the airbox and installed an aftermarket exhaust your bike now breathes alot more.

your airbox is able to pass through more air and your exhaust lets it out much faster.

now, since your allowing more air INTO the cylinder you need to add fuel also. this will give you a better air/fuel ratio.

your "idle circuit" sucks air through the airbox and fuel through the pilot jet. as for the pilot jet, the bigger the number-the more fuel is added. but with your modifications you only need to go up 1 or 2 sizes. THEN adjust the fuel screw accordingly...while the bike is warm!

  • William1

Posted April 22, 2009 - 05:35 AM

#9

Starter jet only works when the choke is pulled. No starter jet would make choke starts incredibly rich. You can try both the hot start and choke at the same and see if things seem better, if so you know there is a jetting issue with the choke.

Airbox mods have no effect on starting.

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  • jhmotard

Posted April 22, 2009 - 06:31 AM

#10

william1 i know your good at jetting, can you verify my response? just wondering

  • CanadianWR450

Posted April 22, 2009 - 07:10 AM

#11

William1, you may be onto to something, because one thing I noticed is that when the bike is running, and I pull the choke, it seems to rev/idle much higher then before, looks like I'll be going into the carb to make absolutly sure of a few things.
I do not have a JD Jet kit yet.....since i have to go back into the carb.....good exuse as any haha! (I know the JD Kit would not affect starting)

I did not change anything in the carb other then cleaning it, and going from a 160 main, to the 168, because the air box mod was done before, and the only mods were the pipe, and cam's. I did not think that those would change the starting/very bottom at all really, so did not change any jetting for bottom/starting (except the adjustable fuel screw).

I have done the "Pilot Circuit verification test" twice now, and to be honest, I got different results, unless I messed something up.

Just to make sure I have this right:
" with bike warmed up, and idleing, turn in fuel screw until idle starts to drop/miss, etc..then turn in until idle picks up/smooths out. This should be between 1 and 2.5 turns out"

The "1 to 2.5 turns out" is from when the fuel screw is ALL the way in, right?
As in....I turn in until sputters, turn out till smooth, and if I now turn ALL the way in, it should have taken me between 1 to 2.5 turns to get there (bottomed out screw)......
and not, turn in till it sputters, then turn out until it gets smooth, and THAT amount of turns should be between 1 to 2.5 turns.....right??

Have I mentioned I love this forum lately?

  • William1

Posted April 22, 2009 - 08:23 AM

#12

william1 i know your good at jetting, can you verify my response? just wondering



A stock bike is mildly restrictived with the airbox and the exhaust. But, the restrictions do not matter until the velocity of the air going in and the exhaust going out is high. Try this. Put a straw in your mouth. Very slowly (engine at idle), inhale through it. Not a problem, right? Add a second straw, again, inhale slowly, no real change, right? So opening up the airbx and/or exhaust makes no difference at idle. Now, with one straw, exhale fast, tought to do. Add a second, gets a little easier. Now you are able to realize the benny-fit of the opened airbox and exhaust.
With engine breathing, you want the intake and exhaust (for the most part) to be free breathing enough so adding 'one more straw' makes no difference. The only times you do not want this is when the bike must be quiet or is setup for low rpm running.

  • CanadianWR450

Posted April 23, 2009 - 02:59 PM

#13

Well, I'm very glad to report that I have figured it out....

It is 44 degress here right now
Gas on
Choke on
Do not touch the throttle
3 kicks, it was running

  • William1

Posted April 23, 2009 - 03:25 PM

#14

What did you figure out? Or... what were you doing before?

  • CanadianWR450

Posted April 23, 2009 - 03:51 PM

#15

Well, I figured out how to kick start my bike....lol

I had been trying a couple of twists of the throttle...

First I tried choke, couple of twists....didn't work well..
Next day
A couple of twists, with no choke..still wasn't it...
Tonight, choke, NO throttle, 3 kicks....going...so that is what I'm sticking with!

  • William1

Posted April 23, 2009 - 05:10 PM

#16

LOL, so you did the experiment backwards!

Basic rule is with a new to you bike is:
Fuel tap on, kick bike-->No start?--> Put on choke, kick bike--> No start?-->
Two quick twists of throttle, kick bike-->No Start?--> Delve into Fuel Condition/carb/ignition/valves/Ext.

Once you have developed a relationship with your bike, you will know what she wants, when she wants it. Like a wife/girlfriend, she will not tell you you what she wants, you must figure it out and remember.

  • CanadianWR450

Posted April 24, 2009 - 01:10 AM

#17

We actually did what you say originally, BUT, that is when we figured out the float was sticking in the carb, and the bike would flood just by looking at it funny...got that sorted out, and yes....then I guess I went backwards....eheh, I'm not used to carbs not wanting a little fuel to kick off....lol

  • o2golfpar

Posted April 24, 2009 - 08:41 AM

#18

Looks like you got this undercontrole but with my new wr450 i choke it then push the kick starter half way down and then let it come up then quickly kick it. This is what works for me.

  • CanadianWR450

Posted April 24, 2009 - 10:11 AM

#19

Ya, I have it under control, went out again today, 3rd kick, it was purring.
I ordered in a new choke plunger, mine keeps popping in by itself, which was NOT helping my experiment in learning how to start this thing at all.

Once that's in, I'm done, the thing is working amazing after the work over the winter, I know how to start it now, and it's easy to start (once you know how), so I won't worry about my e-starter till next winter. I'm good to go!




 
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