Valve Job Q's


6 replies to this topic
  • gloft

Posted January 22, 2007 - 01:35 PM

#1

I adjusted my valves last summer (about 900 miles ago) while doing a top end job. Center intake was right at the minimum with the outside ones about mid way per spec. I have at least 7k miles on the engine and this was the first time it needed a valve adjustment - pretty amazing! Just checked them today after 700 hard miles in Colorado and a few hunderd miles here in Ga and the center one is less than .05 mm - ouch! I'm assuming it's time for a valve job as I've heard that once they start moving, especially tighter, that won't stay adjusted long. This being said I have a few questions for the experts:

1. Does it make sense to re-shim or should I just go ahead and bite the bullet?
2. Should I replace the timing chain while I'm at it (I assume yes)?
3. Anyone replacing their head vs having the valve work done? What's the price difference?
4. Can you buy a new head with valves already installed and ready to go? If so where?

Thanks in advance :lol:

  • gloft

Posted January 23, 2007 - 01:49 PM

#2

Really need some advice on this one so I'm re-posting . . . Indy are you out there?

  • clutcher

Posted January 23, 2007 - 05:20 PM

#3

[COLOR="Navy"][/COLOR]Check with randy at www.fastmannracing.com . He just did a head for me and it looked NEW. He has a new seat & guide machine that does a outstanding job. His price was fair for what all he done.

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  • 642MX

Posted January 23, 2007 - 05:43 PM

#4

I adjusted my valves last summer (about 900 miles ago) while doing a top end job. Center intake was right at the minimum with the outside ones about mid way per spec. I have at least 7k miles on the engine and this was the first time it needed a valve adjustment - pretty amazing! Just checked them today after 700 hard miles in Colorado and a few hunderd miles here in Ga and the center one is less than .05 mm - ouch! I'm assuming it's time for a valve job as I've heard that once they start moving, especially tighter, that won't stay adjusted long. This being said I have a few questions for the experts:

1. Does it make sense to re-shim or should I just go ahead and bite the bullet?
2. Should I replace the timing chain while I'm at it (I assume yes)?
3. Anyone replacing their head vs having the valve work done? What's the price difference?
4. Can you buy a new head with valves already installed and ready to go? If so where?

Thanks in advance :lol:


1. Bite the bullet. Once the valve needs adjustment more than once, typically the hard coating is gone. Its going to keep getting tighter until it breaks.

2. Yes, replace the timing chain yearly.

3. Yamaha heads are high dollar, stop thinking about replacing it. Most machine shops can touch up your seats for a small cost. Never replace the valves without touching up the seats.

4. See answer number 3.

And keep your air filter clean and well oiled. A dirty air filter passes dirt and wears the hard coating on the intake valves.

  • gloft

Posted January 24, 2007 - 11:40 AM

#5

Thanks for the feedback. I have a quote from a local shop that does good work. Their price for the head work, replacing with new OEM valves, springs, keepers, etc plus timing chain and new head gasket is around $900 - ugly. Anyone else had this done recently?

  • Rich_in_Orlando

Posted January 24, 2007 - 02:26 PM

#6

I've got 25,000 miles on my head and valves. I've had to adjust them (as in, replace the shims) a few times. They have stabilized and I've not had to adjust them for a couple of years now. Spend your money on stuff that counts.

  • Birdy426

Posted January 24, 2007 - 09:29 PM

#7

900 bucks sounds like a lot of money...thill you start adding things up. 60 or so bucks a piece for valves (from TT store) is 3 bills real quick. Another benjamin for the springs, seals, keepers, retainers and shims, and about a buck for the timing chain, gasket kit, oil filter, new rings and circlips, etc. Another buck and a half for cutting the seats, and you're at 650 just in parts and machine work. Throw in another buck and a half if you need new guides (and a buck to press all 5 of 'em in, too). If they are going to do the teardown and reassembly, it ain't a bad deal (again, assuming it includes all parts).

As far as when to do it, rule of thmb is when you have to shim twice (because they were too tight), it's time to replace.




 
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