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GONE1445

01 yz426 maintaince tips

18 posts in this topic

ok I have owned my bike for a while and I think its time to do some regualr check ups

1.) how exactly do you check and if need be adjust the valves

2.) if I keep on top of valve wear and replace them early will I ever have to get new seats machined??

3.) how do you adjust the clutch for wear??

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One word: Manual! The YZF manual is the greates come-with-bike manual I have ever had. Tells you everything!

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I hear a lot of guys on here doing there own valve checks/adjustments. Without the proper tools and know-how I would be weary. I just took it in to have it done. Cost about $225.

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Valve check for me is $60. But Im unsure how much it costs to adjust. Im getting all the tools I need though, and start doing it myself.

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yeah, it's only $65 for me, but that starts to wear on the pocketbook a bit after a while.

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The manual can be found here. Valve check/adjust can be found on pages 3-19 → 3-23. http://motoman393.thumpertalk.com/tech/files/426_manual.html

Remove the gas tank, get the motor at TDC (explained how in the manual), remove the head cover and measure the gap between the cam lobe and bucket with a feeler guage. If the are not within spec (.0039 → .0059 intake & .0079 → .0098 exhaust ) then you'll need to reshim, which requires removing the cam caps and swapping the shim under the buckets. The chart on page 3-23 will determine which size shim is needed based on the measurement taken. If they are all within spec then you're done. Button her back up and ride.

Keep track of your measurements pertaining to which valve you are checking. Draw a diagram on paper with the 3 intake and 2 exhaust valves and write each measurement next to the respective valve. If you do need to reshim make sure that you keep track of where each bucket came from and that it goes back to the same place it was originally found. Don't swap bucket locations as they may differ in size and cause false readings upon reassembly. Please note you will need a quality 1/4" torque wrench capable of reading up to 75in/lbs for reassembly of the cam caps.

It's really not a difficult job. I'd rate it 6/10 on my mecahnical aptitude scale and its something certainly worth learning.

Pull the cover, get the measurements and report back if you feel you need additional help. There's lots of well-qualified people here willing to help.

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How did you find that link? I've been through the motoman site and never found anything like that. :thumbsup:

They have it noted as the 2001 426, but it should be basically the same manual as the '00 right? or do they have one for the 2000?

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The valve specs are different for the 2000 since the valves are SS and not Ti, but the procedure is the same. I'll post the 2000 426 specs later after I run out to the garage and check my manual.

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what about the clutch what do I do with the adjuster on the perch

Dude, seriously, get a manual. It will be much much easier and less frustrating for you than having to wait for people to respond to your posts. Best investment you'll make in your bike.

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Dude, seriously, get a manual. It will be much much easier and less frustrating for you than having to wait for people to respond to your posts. Best investment you'll make in your bike.

So true, butta. What surprises me too is that those who have the manual don't even bother to read it. It is so easy to ask instead of doing a little work yourself.

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Also you can get the parts manual from the yamaha web site. It will come in handy where disassembling and reassembling components, or you dont think your dealer is giving you the right part. Lik that never happens.LOL. :thumbsup:

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The manual can be found here. Valve check/adjust can be found on pages 3-19 → 3-23. http://motoman393.thumpertalk.com/tech/files/426_manual.html

Remove the gas tank, get the motor at TDC (explained how in the manual), remove the head cover and measure the gap between the cam lobe and bucket with a feeler guage. If the are not within spec (.0039 → .0059 intake & .0079 → .0098 exhaust ) then you'll need to reshim, which requires removing the cam caps and swapping the shim under the buckets. The chart on page 3-23 will determine which size shim is needed based on the measurement taken. If they are all within spec then you're done. Button her back up and ride.

Keep track of your measurements pertaining to which valve you are checking. Draw a diagram on paper with the 3 intake and 2 exhaust valves and write each measurement next to the respective valve. If you do need to reshim make sure that you keep track of where each bucket came from and that it goes back to the same place it was originally found. Don't swap bucket locations as they may differ in size and cause false readings upon reassembly. Please note you will need a quality 1/4" torque wrench capable of reading up to 75in/lbs for reassembly of the cam caps.

It's really not a difficult job. I'd rate it 6/10 on my mecahnical aptitude scale and its something certainly worth learning.

Pull the cover, get the measurements and report back if you feel you need additional help. There's lots of well-qualified people here willing to help.

Excellent info. Are there any warning signs -Hard to start, backfiring, fouling plugs, engine noises, etc.. that is an indication it's time to adjust them?

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