YZF 426 Problems.

9 replies to this topic
  • Insaneman1731

Posted December 13, 2006 - 04:39 PM


Hello. I am thinking about buying a 426 from a relative. I got it and it was very hard to start. All the time it was just a bitch to start. So some people said it probably just needs the valves adjusted. So I take it to a shop and tell them to take a look at it. They call me and tell me that it does indeed need the valves adjusted so that will be $150. Then they call me back a little later and tell me that the cam chain is stretched and to fix that and the valves will be $400. I am kinda stuck and don't know what to do. Also just wanted to know, is it shims or a rocker arm? And Is it the cam chain of the tensioner?

  • grayracer513

Posted December 13, 2006 - 04:52 PM


If it had good compression, the valves weren't the reason it wouldn't start. They may need to be adjusted anyway, though. The price to adjust the valves is not unreasonable, but the price to replace the chain at the same time seems a little high unless they intend to replace the tensioner and guides as well. The tensioner most likely does not need replacement, and the guides can be visually inspected. By their price on the valve adjust, I'll guess that they charge about $75/hr. The labor to replace the chain while doing a valve adjust should not be more than 3 hours, or $225, and the chain for a 426 around $45. Ask them for a better explanation, in person.

  • 642MX

Posted December 13, 2006 - 05:15 PM


That seems way to high. I think Grayracer is right, its time to make an appearance at the dealership.

  • Insaneman1731

Posted December 13, 2006 - 06:48 PM


Yeah, the price is $70/hr.

  • MichiganMXer

Posted December 13, 2006 - 08:07 PM


You've got the response from some experienced 426'ers. These guys have given some great advise over the YEARS...

How bout some cheap remedies first:

1. Address the fact that they're hard bikes to start without getting the hang of it. You just can't roll up to a 426 with the manual decompression and start it. It takes practice, but once you get the hang of it, its cake.

2. Don't put shitty gas in it. Not that you have but sometimes people bitch about fouled plugs, rough starts etc. when actually they got some stale gas from some hicktown gas station that sells 3 gallons of premium every 3 months.... Change the plug, drain the gas & float bowl and put some good gas in there.

These are some considerations that cost at the most $10 vs. $500.

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  • grayracer513

Posted December 13, 2006 - 08:49 PM


What you have said is quite true. The problem that the OP now has, though, is that he apparently doesn't feel competent or knowledgeable to handle the problem himself, and because he authorized the inspection of the valve clearances, he will be charged at least $70 if he tells them to do nothing and takes his bike home.

If either of us had been around before he went to the dealer, we might have recommended a different course of action, but it's a little late now.

If he really can't do this kind of work himself, then he'll have to pay someone else. But how much and for what? That's the question.

Overall, Insaneman, if you don't have the money to spend on this kind of work, which is fairly minor, and you haven't got, or can't learn the basic skills involved in doing them fro yourself, then I'd say you should probably have the dealer put it together and take it back to your relative and forget the whole thing. There will be more maintenance required in the future.

OTOH, if the bike is in good shape, you may very well have nothing more than oil and filters do deal with for the next year. But you should know what your getting into, and figure out how you're going to handle it if it doesn't go totally well.

  • Insaneman1731

Posted December 22, 2006 - 06:33 AM


I'm thinking I am going to keep it now.

  • Florida_426

Posted December 23, 2006 - 07:09 AM


I am glad to hear you are going to keep the scoot. Get a Yamaha shop manual if the bike doesn't come with one and learn the maintenance procedures yourself. The valve adjustment and cam chain are nothing to be leary of. Take your time and read through the steps first. And listen to any advice Grayracer gives you, the man knows his stuff!!!


  • buzzgrizz

Posted December 23, 2006 - 12:06 PM


If you follow the procedure explained numerous times on this forum it will make starting it a whole lot easier.

  • yz_for_me

Posted December 23, 2006 - 03:06 PM


Insaneman, just curious, are you using the tried and true 426 starting drill? If not you will make your life SOOO much easier if you do? If you don't know it here's a quick overview.

1. Never ever touch the throttle before or while starting (if it's really cold out, some people will give the throttle 1 or 2 quick twists before starting, but I've never found this to work)
2. If the bike is cold use the choke. If it's hot use the hotstart
3. Slowly kick the bike over till you reach top dead center TDC (that's where it gets really hard if not impossible to kick through the stroke)
4. Let the kick start come back up
5. Pull in the manual compression release and push down on the kickstart about an inch (just enough to get past TDC)
6. Let go of the comp. release
7. give it a good kick. You shouldn't have to kill it, just a good solid kick all the way through should work. Also, don't twist the thorttle while kicking
8. If it starts, good, if not repeat the process

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