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Question regarding Valve issues

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Looking into getting a new bike, and have been looking into a Honda. However, I understand they have multiple issues related to valves. What years should I beware of and are there any type of fixes for these problems?

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What I would do is order a new head from pro circuit or fast heads and sell you stock head on eBay. The stock parts do wear out very fast and you can get a lot more performance out of an aftermarket head and parts

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The older heads, pre 06, had more valve issues. If you run a big cam with stiffer springs you will have valve issues. Especially if you're a revver. The only issues that I've seen with newer fi bikes have been maintenance issues . Unless it's a modded motor with a fast rider. When you say new, do you mean brand new? If yes don't worry about it. The new bikes are fine.

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The valve issue was few and far between considering the number of bikes sold. No one I have ever met with a CRF has had premature valve problems. I just replaced the stock head on my 06 450R because it needed it's third reshim. At 300 hours, that's pretty decent valve life. I bought a used low hour head on ebay for $100 and the bike is fine for another 300 or so.

My 05 250R is still running strong on the stock head.

What I like about CRFs is that #1 they are the nicest to work on and #2 parts are so cheap and plentiful.

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Looking into getting a new bike, and have been looking into a Honda. However, I understand they have multiple issues related to valves. What years should I beware of and are there any type of fixes for these problems?

The only reason anyone has valve issues is because they run the oil too low. The case is split in 2 for the motor and tranny so each side has it's own oil. The oil burns quicker because there's less of it in the motor side which causes heat which causes valve issues. Simply make sure you have enough oil every time you ride and change it often. I'm a 100 hrs on my valves and they've only moved a thousandth of an inch.

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The only reason anyone has valve issues is because they run the oil too low. The case is split in 2 for the motor and tranny so each side has it's own oil. The oil burns quicker because there's less of it in the motor side which causes heat which causes valve issues. Simply make sure you have enough oil every time you ride and change it often. I'm a 100 hrs on my valves and they've only moved a thousandth of an inch.

idk how you developed that theory... Generally poor air filter maintenance is the leading cause of premature valve failure

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idk how you developed that theory... Generally poor air filter maintenance is the leading cause of premature valve failure

You're both wrong. The problem was in the construction. Honda had issues with the coatings on the valves and they were running too hard a seat material. Guys were losing a valve on the same weekend they bought their new bike in some cases. Thus lawsuits and negative publicity.

On the other hand, many guys have had fantastic valve life on the limiter with terrible maintenance. Just like any other brand of 4T race bike.

Edited by sandlvr69

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Oil has nothing to do with valves

Try running your motor with low oil for a few hours and see.

Low oil = heat = valve stems stretch prematurely. 

 

You're both wrong. The problem was in the construction. Honda had issues with the coatings on the valves and they were running too hard a seat material. Guys were losing a valve on the same weekend they bought their new bike in some cases. Thus lawsuits and negative publicity.

On the other hand, many guys have had fantastic valve life on the limiter with terrible maintenance. Just like any other brand of 4T race bike.

It's not wrong, but thanks for your opinion.

 

idk how you developed that theory... Generally poor air filter maintenance is the leading cause of premature valve failure

It's not my theory, it's from a Pro Mechanic. Of course material getting into the head will cause issues but I don't think that's the issue the OP was talking about as that would be the case with any bike. I could be wrong but I assumed he was talking about them going out of spec quickly. 

Edited by reefsafe

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Can't get much hotter than having fire on and around them all the time

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Try running your motor with low oil for a few hours and see.

Low oil = heat = valve stems stretch prematurely.

It's not wrong, but thanks for your opinion.

It's not my theory, it's from a Pro Mechanic. Of course material getting into the head will cause issues but I don't think that's the issue the OP was talking about as that would be the case with any bike. I could be wrong but I assumed he was talking about them going out of spec quickly.

oil doesn't touch the valve seat face which is where the wear occurs. I don't think the issue these bikes have is with stretching the stem or "tuliping" the valve, which can happen when they get too hot.

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I think low oil will cause a bunch of other issues before it will cause valves any harm. The issue with the early Honda's was was the seat material more than anything. Once they changed that the valve life has been quite good.

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Try running your motor with low oil for a few hours and see.

Low oil = heat = valve stems stretch prematurely. 

Oil is nowhere to be found at the valve seat and has not a thing to do with premature valve wear. You can call it an opinion but it's so obvious I don't think you'll convince anyone.

 

I'd also love to know what you're smoking if you think titanium intake valves 'stretch'.

Edited by sandlvr69

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oil doesn't touch the valve seat face which is where the wear occurs. I don't think the issue these bikes have is with stretching the stem or "tuliping" the valve, which can happen when they get too hot.

Yes, early years did have coating issues & seat face but that was fixed as noted earlier. I haven't suggested that that was the issue at hand or low oil was the cause. I'm only talking about the valves moving out of spec prematurely, which I believe is a common issue. 

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The only reason anyone has valve issues is because they run the oil too low.

 

Please point to anywhere I said oil & valve seats.

So you are saying that the problems some bikes had were not at the valve-to-seat area? You honestly think that someone who runs their bike low on oil and causes a couple extra degrees of engine heat is stretching a titanium valve? You do know that the bike is water cooled right? It's a pressure oiling system, not splash lubrication. If the level is high enough for pickup tube to get oil to the pump, you will have oil pressure in all the same places you would have it ordinarily.

 

 

 

The earlier bikes had titanium COATED valves no? 

Yes, and still do.

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So you are saying that the problems some bikes had were not at the valve-to-seat area? You honestly think that someone who runs their bike low on oil and causes a couple extra degrees of engine heat is stretching a titanium valve? You do know that the bike is water cooled right? 

 

Sure, some bikes. Seems like you're having an argument about things I haven't said? 

So water cooled bikes don't overheat more than a couple degrees? And as long as they have the minimal amount of oil you have nothing to worry about. Got it! 

Edited by reefsafe

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Amount, or type, of engine oil has nothing to do with the valve face-to-seat wear (from dirty intake charge) that can occur in these motors.

Edited by Eddie8v

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Sure, some bikes. Seems like you're having an argument about things I haven't said? 

So water cooled bikes don't overheat more than a couple degrees? And as long as they have the minimal amount of oil you have nothing to worry about. Got it! 

I have no idea what your argument is at this point. But I'm glad I was able to educate you about liquid cooling and the pressure oiling system at least- they are fundamental to making your bike last.

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Well I hope that these new honda oem valves I just installed is not new old stock lol just had a 06 full rebuild done and put the bike back together tonight, seats cut , head ported 13.5 piston ect , I'm excited to fire this thing tomorrow ,if I knew how to post a pic I would show anyone interested what a right side intake looks like from poor air filter cleaning , not pretty at all , wish me luck

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