Purchased 2000 yzf 426 and it won't start

37 replies to this topic
  • 1st_yzf426_myfoothurts

Posted March 17, 2013 - 09:02 AM


Yesterday I bought a yzf426. I took a chance and couldn't get it started but. Most everything checked out ok on the bike but after getting home and changing the plug it won't fire up. I know there is a procedure to Wich I have followed with no results. I pulled the plug again and it is pretty wet no discoloration just clean gas. I grounded the plug to see if I got spark and I do it just seems weak to me. Could weak spark make it not fire up?

  • marv02

Posted March 17, 2013 - 09:10 AM


I weak spark can keep the bike from starting have you done a compression check yet.

  • 1st_yzf426_myfoothurts

Posted March 17, 2013 - 09:13 AM


I have not done a compression check.

  • capt justin

Posted March 17, 2013 - 09:17 AM


yea so can your valve clearances

  • 1st_yzf426_myfoothurts

Posted March 17, 2013 - 09:39 AM


Well like I said I took a chance I only paid 700 for the bike so I still think I did ok would just like to figure out what the actual prob is.

  • etuke

Posted March 17, 2013 - 09:56 AM


without the decompression lever pulled you shouldn't be able to kick it through the stroke if compression is good,if rings are worn or the valves aren't seating then you will be able to kick it over without the decomp.Mine locks solid without using the lever.Make sure you ain't twisting the throttle while kicking,keep your hand off the twister to be sure.

Edited by etuke, March 17, 2013 - 09:58 AM.

  • 1st_yzf426_myfoothurts

Posted March 17, 2013 - 10:09 AM


Yes I def cannot kick through with out the decomp lever being pulled just like the videos shown. You can push it down till it hits top dead then it will not budge. Until I pull the decomp lever.

  • 1st_yzf426_myfoothurts

Posted March 19, 2013 - 07:05 AM


A guy at work recommended that I check the valve clearances just like a couple of u have stated already. Does anyone know what the tolerance range is for this bike? I have ordered a manual but hasn't came in yet

  • etuke

Posted March 19, 2013 - 07:27 AM


if the compression is there trying to kick it over then I seriously doubt the valves are out of spec enough to not start it.When the valves go out of tolerance what happens is they tighten up to the cam and don't close fully causing a loss of compression.I would get into the carb and clean it good and change the pilot jet as they are not expensive.Also check the timing to make sure it didn't jump,if the spark looks weak then check the plug cap and wire for corrosion also change the plug.

  • 1st_yzf426_myfoothurts

Posted March 19, 2013 - 07:32 AM


I did change the plug I have not looked at the wire or the coil yet. I kinda figured I'd have to clean the carb good since the guy said he had never done it. And even though there is gas getting to the plug I still need to change the pilot?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • etuke

Posted March 19, 2013 - 12:40 PM


it has an accelerator pump so when you twist the throttle it squirts fuel in the intake for cold starts.If you twisted it too much it will flood,I went through all this myself.I kicked the bike over for an hour with just a pop here and there and another guy who had a 426 had it going in 3 kicks.I would start with the carb,most likely where the trouble is.

  • 1st_yzf426_myfoothurts

Posted March 19, 2013 - 01:22 PM


Doesn't seem to tuff. I guess that's what I will do. And then give it another shot. What a pain :) laugh out loud I'm excited to ride it but still in the back of my mind I'm thinkin I shoulda just bought a 450.

  • grayracer513

Posted March 19, 2013 - 01:25 PM


Here's a free manual until your expensive one gets here:


Most of the time, the two biggest things that keep a 426 from starting are a fouled plug (get a new one, not a clean one) and problems with the idle (pilot) circuit in the carb.

  • 1st_yzf426_myfoothurts

Posted March 19, 2013 - 01:27 PM


Awesome thank u so much

  • 1st_yzf426_myfoothurts

Posted March 19, 2013 - 03:36 PM


Well I pulled the carb off unscrewed the screws for the float bowl and when I lifted off the bowl the main jet fell over. Maybe that might be why the bike won't start.

  • Far916

Posted March 20, 2013 - 08:11 PM


Lol, yeah that might have something to do with it.. while carb is out, clean it good...

  • 1st_yzf426_myfoothurts

Posted March 21, 2013 - 07:55 PM


I cleaned everything and put the carb back together and still will not start doesn't pop or sputter does absolutely mothing.

  • pembell

Posted March 22, 2013 - 12:53 AM


Hi, I've got a 2002 426. Sounds like you've done all the right things - the only thing I think I can add is that if you don't get her started on the first three or four goes, you need to leave her for a little while before she will start. They seem to flood quite easily. As the previous poster said, do not touch the gas while kicking her over!

I take it your air filter is clean? Mine won't start immediately after I clean and oil the air filter. I have to kick it, then leave it 10 mins or so, then she's fine again.

  • 1st_yzf426_myfoothurts

Posted March 22, 2013 - 04:14 AM


Well after re-watching the how to start video I feel like I may have been doing wrong. When I watched it the first time I thought it said to hold the decomp lever while kicking the bike. Turns out that is not the case. So I guess would the bike really not start if I had the decomp lever pulled in while trying to start it?

  • marv02

Posted March 22, 2013 - 05:02 AM


have you tried this with the gas turned off pull in the decompression lever kick the motor though 5 or 6 times put the motor on TDC turn the chock on turn the gas then try to start the bike this how I use to start my 426 before I installed my hot cams.

I still do this every now and then.

Related Content


Snake pit oct 30th by The Anvil

Dirt Bike   Dirt Bike Regional Discussion   California
  • Hot  293 replies

BIGBORE FOR YZ450F 2006? by Taattie94

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 5 replies

The "going back to the other darkside" adventure... by Monk

Dirt Bike   Make / Model Specific   KTM   250/350/450/505 SX-F & XC-F (4-Strokes)
  • Hot  113 replies

James Stewart back on a YZ450F by YamaLink

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies

Should I buy this bike? help....... by Numsa Hul

Dirt Bike   General Dirt Bike Forums   What bike should I buy?
  • * * * * *
  • 10 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.