No throttle response from 99 WR400F after Carb cleaning!


13 replies to this topic
  • adamcolliss

Posted May 07, 2012 - 09:48 PM

#1

Hi

Firstly, I've had a search of the forums but couldn't find any information, but apologies if I've missed a post with the same problems.

My WR has been stood up for near on a year, at the weekend I decided to get it back up together, unfortunately it wouldn't kick over. I put in fresh fuel, new spark plug but still no joy. Checked the spark plug and had a good spark and petrol was flowing.

I then took the carb off and carefully took it apart, cleaned it out and put it back together (I think correctly but this was my first time at this!). I could now get the bike to start but unfortunately the throttle doesn't do anything! The cables are connected to the cam and I can see the cam turning when I twist the throttle but get no response, rev's dont change.

Any ideas what I've done wrong!

Many thanks in advance,
Adam

  • MANIAC998

Posted May 08, 2012 - 03:37 AM

#2

Did you remove the slide while you were cleaning the carb? It sure sounds like the slide isn't being lifted while turning the throttle.
Maniac

  • allterra

Posted May 08, 2012 - 07:54 AM

#3

Did you remove the slide while you were cleaning the carb? It sure sounds like the slide isn't being lifted while turning the throttle.
Maniac


second his thought. It sounds like you may be sitting on the idle circut. Most other probs you would run into on a previously working carb would be a bog or flooding.

  • byggd

Posted May 08, 2012 - 12:23 PM

#4

I seem to remember that the slide on these can be installed backwards. This will cause all kinds of problems.

  • adamcolliss

Posted May 08, 2012 - 09:34 PM

#5

Thanks for all the replies, does sound like I've fitted the slide wrong, I'll take a look at the weekend!

Thanks again!

  • byggd

Posted May 09, 2012 - 12:20 PM

#6

If it is in backwards just blame it on gremlins sneaking into your garage ;-)

Let us know how it turns out.

Edited by byggd, May 09, 2012 - 12:21 PM.


  • adamcolliss

Posted May 14, 2012 - 10:11 PM

#7

I (or the gremlins) forgot to connect the slider to the link arm!

Still having problems starting the bike though, does anyone know what the stock setting for the fuel screw should be? (I've read anywhere from 1/4 of a turn to 2 turns out). I've got it on 1 + 1/4 turns out and the bikes not starting...

Any advice greatly appreciated.

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  • wrwest

Posted May 15, 2012 - 02:08 AM

#8

Now you went and broke it.........

  • MANIAC998

Posted May 15, 2012 - 03:49 AM

#9

For a cold engine, twist the throttle three times, choke on, kick it or use the button sparingly. It should fire up in just a couple revolutions. What model bike are we talking about anyhow? 400/426/450?
Maniac

  • adamcolliss

Posted May 16, 2012 - 12:58 AM

#10

Hi

Thanks I'll give that a go, though I'm sure that's how I normally start the bike. Its a 99 WR400. Would the fuel screw being set wrong not affect the starting?

  • MANIAC998

Posted May 16, 2012 - 03:43 AM

#11

Fuel screw shouldn't have any effect on starting. Idling, yes. But not starting. With the 400, you don't have the automatic compression release, so you have a "routine" that you have to go thru for starting. Here's how my routine for my old 400 went:

Cold Engine
- Choke on, three twists of the throttle. Push kickstart lever down until you find massive engine compression(TDC), then pull in compression release so as the kickstart lever only moves approximately 1" past TDC. Release the compression release. Remove hand from throttle! Place it on the front master cylinder, so you don't accidently twist the throttle while you go thru the next step. Next, kick! It doesn't have to be a super-hard kick, but should be a full-kick all the way thru the stroke. This gives the engine the best chance of firing when the piston has enough speed when it reaches TDC on the next revolution. This sounds waaaaaaayyyyyyyy harder than it actually is. Within just a few kicks, you'll have the routine down pat, and will be able to kick like a pro!

Let us know if this is the procedure you've been using.
Maniac

  • adamcolliss

Posted May 17, 2012 - 09:59 PM

#12

It starts! Many thanks for your help, I was following a similar start procedure but pulling the compression lever in while twisting the throttle before attempting to kick it over, that seemed to work for the last 9 years but for some reason after I cleaned the carb no longer!

Still got one issue which I'm guessing might be the fuel screw, bike runs with the choke out, but as soon as I push it in (after leaving it running for a couple of minutes with choke out) it dies. Could this be the fuel screw? Its 1 1/4 turns out at the moment, which way should I go if it is?

Thanks again
Adam

  • MANIAC998

Posted May 18, 2012 - 04:26 AM

#13

If it needs choke to run, then you are lean. So you would need to turn the fuel screw out, which lets more fuel flow thru the passageway and into the engine. What size pilot are you running? What's your elevation? Temp?
Maniac

  • Rocky739

Posted May 20, 2012 - 06:39 AM

#14

It starts! Many thanks for your help, I was following a similar start procedure but pulling the compression lever in while twisting the throttle before attempting to kick it over, that seemed to work for the last 9 years but for some reason after I cleaned the carb no longer!

Still got one issue which I'm guessing might be the fuel screw, bike runs with the choke out, but as soon as I push it in (after leaving it running for a couple of minutes with choke out) it dies. Could this be the fuel screw? Its 1 1/4 turns out at the moment, which way should I go if it is?

Thanks again
Adam


Read the pinned post about choosing the correct pilot jet, my bike is a completly different animal just going from a 45 to a 48 pilot (starts easier, only needs choke for a few seconds and fuel screw adjusts for max idle at about 1.25 turns).




 
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