YZ426F- STILL a sonofagun to start


22 replies to this topic
  • salukikev

Posted September 12, 2011 - 12:25 PM

#1

It could be my technique in kick starting my yz426F (I think it's a 2001), but I've never had a great deal of success. My procedure is the following:
1. Open the fuel valve.
2. Check to make sure its in neutral.
2.5 (edit) Check that the cold choke is out and hot choke in.
3. Hold in the decompression lever.
4. Kick it a few times to loosen things up.
5. Release lever, kick till it freezes (tdc).
6. Hold in lever again and advance a few more degrees.
7. Release leaver- Kick it as hard as I can.

Usually- I spray some ether into the plastic port holes in the back.
All that and it STILL fights me every time. I've literally kicked a hole though the bottom of my shoe trying to get it to cooperate.

Once it starts, everythings fine, but its been sitting for over a year now- mostly due to frustration and my readily cooperative street bikes. (this is modified & plated to street legal)

Any tips and/or places in or around Charlotte that are experts in this bike that I could take it in for a tune up?
Thanks for any help!
-kevin

  • sid_125_04

Posted September 12, 2011 - 01:42 PM

#2

Mine is still a little touchy too even with a hot cam mod when its cold i twist the throttle twice pull the choke and then kick and it fires right up first kick....

  • Ranger426

Posted September 12, 2011 - 02:36 PM

#3

I have an '01 and I pretty much use the same process as you stated. I usually have no problems, starts 1st or 2nd kick. Although somebody told me the other day to not kick as hard as I can, just kick it and it'll start easier. Idk if there is any truth to this though, have not tried it yet.

  • zaxcar1

Posted September 12, 2011 - 04:32 PM

#4

mine did that too. it had a lot of crap in the carb. took it to a guy and he had the carb soaking for 2 days to clean it.

  • Boosted2M6

Posted September 12, 2011 - 05:07 PM

#5

Seems like you may be doing it wrong... or I'm not reading what you're trying to explain correctly.

Mine starts first kick, by doing this:

1) Kick down slow until it stops.
2) Return kickstart to full upright position.
3) Engage compression release lever.
4) Kickstart one full swing, all the way to the bottom - medium kick strength - not to fast, but not to slow.
5) Release compression lever, return kickstart to upright position.

Lastly one final good kick, and she'll fire right up. Typing this sure does seem like quite the effort to start a bike, but in reality it only takes like 3 seconds :)

  • grayracer513

Posted September 12, 2011 - 06:14 PM

#6

4) Kickstart one full swing, all the way to the bottom - medium kick strength - not to fast, but not to slow.

It seems more like you are doing it wrong:

http://www.yamaha-mo...troke_vid_a.mpg

http://www.yamaha-mo...troke_vid_b.mpg

  • CRF100biker

Posted September 12, 2011 - 07:15 PM

#7

It seems more like you are doing it wrong:

http://www.yamaha-mo...troke_vid_a.mpg

http://www.yamaha-mo...troke_vid_b.mpg


this.

i'm not sure where most of you get your crazy start up methods, but the yamaha manual states no throttle should be applied, choke on, kick to tdc, decompress slightly past tdc, let go of the decomp and kick it over. my bike starts up within 3 kicks cold using this method, 1st kick when warm. every single time. if yours doesn't start easily then something is wrong in the carb, timing or valve adjustment i would have to guess.

  • Boosted2M6

Posted September 12, 2011 - 07:43 PM

#8

It seems more like you are doing it wrong:

http://www.yamaha-mo...troke_vid_a.mpg

http://www.yamaha-mo...troke_vid_b.mpg


I don't know who this guy is, but if I give my bike any type of throttle before starting it, be prepared for a sore foot.

It seems he is doing it wrong.

My bike will start using this method, sitting 2 minutes or two weeks, on the first kick. Choke or hot start obviously depending.

Thanks for trying to help though :)

  • grayracer513

Posted September 12, 2011 - 09:30 PM

#9

I don't know who this guy is,...

That's Doug Dubach, owner of DRD Racing, 15 times World and National Vet champion, and long time Yamaha test rider who was in great part personally responsible for the YZ426 being what it was, and for the very existence of the YZ250F. He's been a Yamaha insider since at least 1999.

The part of your process I'm specifically concerned with is that which I quoted. You suggest pushing the kick crank clear to the bottom after locating compression, and that is wrong.

The crank should be advanced no more than an inch past where compression is found. This allows you to kick through the remainder of the compression stroke and through the ignition point to start the engine without encountering the next full compression stroke.

By doing it your way, which is somewhat the old school thumper method, you pass the complete compression and power stroke and position yourself somewhere between the intake stroke and the next compression stroke, and that means you'll have to kick it through the next full compression stroke on your momentum. That worked when compression was 10:1 and cranks weighed 60 pounds, but not anymore.

  • salukikev

Posted September 13, 2011 - 05:43 AM

#10

Thanks for all the helpful tips, everybody! Sounds like my routine is about right, but its STILL a lot harder than it ought to be. I haven't decided if I want to take the time and risk to try and tune it myself, so if anyone has a suggestion to a shop or particular guy in the Charlotte area who is expert in these, I'd love to hear 'em! I would love to move this bike into my usual commuting rotation! :)
Thanks again!
-kevin

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  • salukikev

Posted September 13, 2011 - 05:44 AM

#11

I don't know who this guy is, but if I give my bike any type of throttle before starting it, be prepared for a sore foot.

It seems he is doing it wrong.

My bike will start using this method, sitting 2 minutes or two weeks, on the first kick. Choke or hot start obviously depending.

Thanks for trying to help though :)


It sounds like the majority disagrees with this approach, but at the end of the day, I'll try anything! Thanks for the suggestion!

  • cowboyona426

Posted September 13, 2011 - 07:01 AM

#12

My 426 and even my 450 like a blip or two of the throttle on a cold start, especially if it's been a while.

  • grayracer513

Posted September 13, 2011 - 07:23 AM

#13

The 426 does actually have kind of marginal spark strength at cranking speeds, so fresh plugs are very important. Some improvement can be made with high output coils or by converting to a "stick coil" (coil over plug design, like the 450). These you can get from a used Hyabusa out of a salvage yard, or off of eBay. Be sure to get the connector terminal along with it if you decide to try this.

But most of the starting problems by far center around the carb. Getting the idle circuit trimmed correctly makes a huge difference. Conversion to a later FCR-MX carb from an '05 up helps a lot too.

  • sid_125_04

Posted September 13, 2011 - 02:48 PM

#14

The 426 does actually have kind of marginal spark strength at cranking speeds, so fresh plugs are very important. Some improvement can be made with high output coils or by converting to a "stick coil" (coil over plug design, like the 450). These you can get from a used Hyabusa out of a salvage yard, or off of eBay. Be sure to get the connector terminal along with it if you decide to try this.

But most of the starting problems by far center around the carb. Getting the idle circuit trimmed correctly makes a huge difference. Conversion to a later FCR-MX carb from an '05 up helps a lot too.


Is that an extensive mod or fairly easy? Meaning is there any machine work?

  • USED YZ426F

Posted September 13, 2011 - 03:31 PM

#15

Have you checked your valve clearances recently? If they are too tight, the bike will be hard to start, regardless of technique.

  • grayracer513

Posted September 13, 2011 - 04:10 PM

#16

... is there any machine work?


No...

  • jer500

Posted September 13, 2011 - 04:23 PM

#17

my technique for my 400f i had and my current 04 yz450f i turn gas on lean bike over till fuel runs out overflow then twst the throttle over slowly push kicker through stroke to tdc let off and one kick they both started right up the 400f was impossible without compression release

  • Boosted2M6

Posted September 13, 2011 - 06:34 PM

#18

That's Doug Dubach, owner of DRD Racing, 15 times World and National Vet champion, and long time Yamaha test rider who was in great part personally responsible for the YZ426 being what it was, and for the very existence of the YZ250F. He's been a Yamaha insider since at least 1999.

The part of your process I'm specifically concerned with is that which I quoted. You suggest pushing the kick crank clear to the bottom after locating compression, and that is wrong.

The crank should be advanced no more than an inch past where compression is found. This allows you to kick through the remainder of the compression stroke and through the ignition point to start the engine without encountering the next full compression stroke.

By doing it your way, which is somewhat the old school thumper method, you pass the complete compression and power stroke and position yourself somewhere between the intake stroke and the next compression stroke, and that means you'll have to kick it through the next full compression stroke on your momentum. That worked when compression was 10:1 and cranks weighed 60 pounds, but not anymore.


I guess it's an old dog / new trick kinda thing. I've been doing it this way since the my first 426 in 02 when I was a teenager, never had a problem and always started like a champ. :)

  • Schpenxel

Posted September 14, 2011 - 05:12 AM

#19

I've been lucky as well--I have had mine sit for over a month before and it still started 2nd or 3rd kick. I did notice that the fuel screw being too far in made it hard to start mine once. But after I set that back where it was prior to messing with it, all was fine.

Speaking of which, I need to order a bigger pilot jet sometime

  • ca_101

Posted September 14, 2011 - 05:24 AM

#20

Yeah, I was gonna mention the valve clearances also. I always have used the EXACT method you described in the OP and my bike always started 1-2 kicks.

If any of my idiot friends decided to hop on my bike, they always gave it throttle, and completely pissed me off, because that usually meant that I had to change the plug. That accelerator pump (even with the BK mod) would foul the plug immediately.

Oh, and I don't think you want to go for a crazy, hard, kick. Just nice and smooth all the way to the bottom, with some steady force behind it....





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