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04 CRF250R and valve problems?

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ok guys, my dad and I went down to the local dealer to talk about getting a 250 and evrything was going good untill we got on thumper and started searching though the posts and couldnt help but to notice all of the valve problems that people have been experiencing. I know this is a site where people come to ask for help for their bikes that may have problems but reading all of this stuff has really got me questioning the reliability of this first year bike. Is this a problem that can be fixed by just switching over to the stainless steel valves? Is this a problem that Honda has fixed for the 05 250? Can you guys give me some insite on what you think about this? Thanks By the way i wouldnt be doing any racing...mostly trail riding and messing around on the track evry now and then...im coming off of a crf 230, thanks again

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There's no solid info yet on whether SS valves are a fix or if the 05 is fixed.

It won't matter how you ride it.

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Going from a low maintenance bike like a CRF230 to a race bike like the CRF250 you will be replacing valves and high wear motor parts no matter what. Its just something that happens with high performance motors depending on how hard you ride the bike. I have not had valve problems with my bike nor have way more than half of the folks on this forum. :cry:

I would buy a 2004 or a 2005 CRF250 with confidence!! Ride it like you stole it from day 1, change oil frequently and have fun!!!! :cry:

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If you are not going to ride it hard, change/check the oil often and valve clearances after the initial 5 hours of run time. The maintenance requirements will definitely be higher than your 230; however nothing someone with some mechanical skills cannot handle. I ride woods almost 100% and am very happy with the performance and handling.

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The CRF230 is really a nice woods/trail bike. The 250 CRF's are designed to be winning race bikes. To get the associated performance, you must be prepared to make trade-offs. I think my 250X requires a little more maintenance than less serious mounts but you should see the size of the grin on my face in the woods.

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just consider that all people post having problems and nobody really post saying they haven't had problems because there is no reason to ! i ride hard and race and my valves have been perfect every time i check them my 2 cents

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I have had my crf250r for 8 months now. I have rode 6 hare scrambles, rode the dunes four times, and hit a couple of poker runs. Not one problem valves right on the money.

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My two cents, I personal know five people that have experienced valve problems with their CRF250X/R. Two of them are working on their third set of intakes. Actually only the right intake seems to be going out but most opt for replacing both when the motor is down. The bike is great. The handling, power and suspension are at the top but my valve problems have soured my taste. All I want is a good reliable trail bike and mine is sitting in the corner of my garage waiting for its’ third right intake valve. If replacing the valves every 500 to 1000 miles is standard maintenance then perhaps this bike is not for me or for you. Just got a phone call make that six bikes not five with valve problems. Kept it in mind all six of these bikes belong to people I personally know and ride with. From my point of view everybody is having valve problems not just a few. My question, if I sell my bike, what do I tell the guy that buys it?

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On the other hand, myself and 5 of my riding buddies have had no valve problems. These are 5 '04 R's and 1 '04 X. A few of them are close to 1 year old, valves have been checked and are fine. None of them smoke or use a lot of oil either. All these bikes are ridden hard!

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That’s great you and your friends are part of the group without valve problems. After my last post, I came up with three bike owners of CRF250 that have not had valve problems yet, that I’ve ridden with before (none of them ride very much). I purchased my bike seven months ago and have about 2000 miles on it. The first valve problem surfaced around 1200 to 1500 miles the second only took 500 miles before its death. From what I’ve seen one day the valves check out good and next day there gone. One friend with a two year old CRF250R kept telling me he had no problems with his valves but over the weekend his are now toast. How much time do you and your friends have on your bikes? It would be interesting to see your comments in few months. Good luck with your bikes

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When you consider that Ducati can't do more then two race meetings on a $100000 superbike motor, 2000 miles on a single cylinder race motor, with a few valves replaced seems great value to me !!! :cry: These things are race bikes, guys who regularly run on the limiter, don't clean air filters as often as they should, or run less then average fuel will have problems, no question. As for the your friends, my friends arguement, I know of at least 15 CRF250R's that are regularly raced, and only 2 have had valve problems, both owned by young, recently converted, 2 smoke riders who don't understand the meaning of " DON'T RIDE ON THE REV LIMITER !!!!! :cry: How many engine rebuilds have you done ??? Add up how many you would have done on a two smoke, along with oils etc, I still think you would be in front on the greatest little 4 stroke in the world !! :cry: My two cents !!!

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First of all, I do not own a Ducati Super bike. Second, I’ve been ridding dirt bikes for almost 40 years. Third, my first four stroke was a 1976 XL 350 Honda, been ridding four strokes close to 30 years. Fourth, I consider my self a fairly good mechanic. Fifth, I do not ride on the rev limiter, no need to. Sixth, not sure how many overhauls I’ve done, but its been a lot. This is the first four stroke I’ve owned that has required more maintains than any of my two strokes. O, bye the way, a clean air filter allows more and larger size particulates to pass than does a dirty filter. Seventh and most important, I did not buy this bike as a racer but as a trail machine. Honda is marketing the CRF250X as an upgrade from the XR series and the general public is not going to except a trail bike that needs to be overhauled every 1000 miles.

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I've been reading about these valve problems on the Honda's, and the Kawasuki's for some time now. I strongly believe that it is a real problem, and that most folks will experience it at some point down the road. I have two KX250F's, and since they are having similar problems, I'll share my experience.

I bought the first bike in October of last year. That one is mine. This was my first MX bike and I am 45 yrs. old. I rode it pretty slowly at first. I ride about 3 times a week, and eventually started racing. I'm still not real fast, but I can do ok in many of the over 40 class races. My bike has had zero valve problems, and again, we ride about 3 days/week.

My son's bike was bought new in January of this year. He is a 125 Novice class rider. He rides hard, but does not come close to hitting the rev limiter. In fact, I've never heard him hit at all. I can't reacall him even panic rev'ing it. His bike started having valve issues about 1 month ago. We decided to replace all the valves, and springs which should complete this week. We also had the valve seats cut, and they needed it. I believe that just replacing the valves may not be the answer by itself. We'll see. Anyway, were batting .500 on valve issues. We maintain the bikes in the exact same way, and are very anal about clean air filters and oil changes, along with checking valve clearances. I belive that once the valve coating is worn, the valves go extremely quickly. We'll see how long the second sets of OEM's last after doing about all you can do to repair the problem.

My son now has an '05 CRF250R. Hopefully, they've improved the technology somewhat, but only time will tell. By the way... my son says he likes the Honda better than his Kawasaki. I've ridden it, and still like the Kawasaki. The Kawasaki still seems to have the low end punch over the Honda, which fits my style. Outside of that, I don't see a heck of a lot of difference in them. I have to admit, the Honda has a very smooth powerband from top to bottom and it's a blast to ride. Just personal preference I guess.

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There is a valve recession issue, but whether or not you call it a problem depends on your perspective.

All of the OEMs are making their high output 4 stroke single dirt bikes with titanium valves. They all have consistantly chosen to run hard valve seats in these heads.

Riding style and maintainence will have some affect on the life of the valves, but the biggest factors are, that titanium is soft,the seats are hard, and the closing velocities of the valve train are high.

I have been looking at this problem for a good while now, and trying to figure out why all of the manufacturers would decide to go down the same road, materials wise.

They chose titanium valves because they are light, and they could keep spring forces to a minimum, which would allow for minimal friction losses in the engine.

Something they had to consider when they made this choice was that titanium does not have a long cycle fatigue life in this type of application. At least not compared to a stainless steel valve. So, they were faced with a choice- use a different seat material that would extend the life of the valve face, but also increase the likelihood that a valve would fail, or, use the hard seat, which will create some recession problems, but not a catastrophic failure like a valve that breaks due to fatigue.

It seems to me after some consideration, that the OEMs use the hard seat like a timer- it stops things before the valves get enough time on them to come apart.

I'm not sure they knew that such a large number of folks would be having to replace parts so frequently, but I would guess they had to have an idea of the average amount of time a rider could expect to get out of a set of titanium valves, both before the faces receeded, and before they broke. I'm guessing they made their materials choices based on those numbers. They wanted to give folks the nth degree of performance, and you have to know that the further you push the envelope, the more you cut into the lifespan of the parts. It makes sense to have the valve face go and not the valve.

As far as the stainless conversion for the 250 heads- we've been working on the Honda, and the Kawasaki/Suzuki collaboration for a while now. Unfortunately the problems with these heads showed up when we had quite a few development projects already scheduled. Recently we have completed those projects, and have been giving all of our attention to these two bikes. We've done some modeling and some testing, and we'll have the components ready before the year is out. The temptation is great to come out with a partial solution, but we are going to stick to our guns and come out with a well thought out and designed set of components that will give folks what they are looking for both performance and lifespan wise.

Mike

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The Yamaha question-

Because the Yamaha utilizes 3 intake valves, the intake valve area, or the area that can be used to fill the cylinder is greater than the two intake valve set up used by everyone else.

This means, that in order to get the same amount of air and fuel into the cylinder as the 3 Yamaha intake valves, the 2 valve heads have to get the valve open quicker, stay open as long as possible, and then hurry up and get shut so that the cylinder can build the pressure required to make power.

Remember- you don't start building big cylinder pressure until all the valves are closed. You could run a longer duration cam and possibly extend the fill time, and ease the closing ramp velocity a little, but you'd be bleeding off pressure (compression)by closing the valve later. This kills the bottom end power.

Now you can compensate a little for that loss of grunt with a higher compression piston, but the more things you change, the more things you'll have to change.

A piston with a dome usually adds weight, and if there is a dome required to get the compression increase, it may affect the flame front that travels across the cylinder.

Additionally, the intake port charge could possibly be overcome by the cylinder pressure as the piston travels upward waiting for the intake valve to close. So, in order to get decent bottom end grunt, and still get enough cylinder fill so that the engine will run at high RPM, the cam profile has to be aggressive in the 2 intake valve setup.

Now- It doesn't happen very often, but we have seen the titanium valves in the Yamahas come apart. Awhile ago Rich Rorich posted some pics on dirtrider.net. At that time he was suggesting folks put an hour meter on their 5 valve stuff so they could keep track of how much time they had on their parts, and change valves before thay had a catastrophic failure. This is the fatigue factor that I was talking about in my previous post.

The guys that have had problems generally don't go back to the ti valves. We did a stainless conversion for all the 5 valve yamaha stuff, and while it doesn't move in the numbers that the 2 valve stuff does, it does sell. Anyone who's lost a cyliner head, cylinder, rod, piston, and case, will generally convert.

I don't know what kind of interval guys have come up with for changing their 3 valve stuff, you get into riding style and maintainence issues here. It's a decision only you can make. Again, once a guy has had a failue, he generally converts to the stainless stuff. But I'm sure there are guys out there that pay attention to the lifespan of these parts, and could tell you what they've done based on the type of riding they do.

Hope this answers your questions-

Mike

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