[fishbill]

Did the 250 R have similar valve issues that the earlier 250 X was known for?

Looking at purchasing a 2006 R as a substitute for a X.

[crfsonly]

I always feel the need to educate when I hear "valve issues". There was never really any "valve issues" from my perspective. Honda made some design choices to keep the avid racer racing less expensively. The valves lasted as long as the design criteria required. Having said that I wish the design choice for the X models had been, and in my mind should have been, stainless steel intake valves. Most of the X market would have preferred more valve durability over the minimal amount of power gained from having titanium valves.

To your question, if you are buying a used '06 CRF250R you should figure into the cost of the bike a professional valve job and new valves like this offering:

https://www.crfsonly.com/catalog/produc ... ts_id/3974

Many who are selling used CRF's have reached the end of the valve life and have shimmed them to sell them. We call this a "shim and sale".

Ken

[JimDirt]

They all had similar issues , but most were contributed to dirt getting past the filter into the Intake tract of the airbox and working its way into the cylinder and beating the seats and valve face (basically sandblasting them) , the parts are "wear parts" , so they do go after time , how much time is relevant to cleanliness and abuse , there is no set "do this and your valves will last forever" solution , its the same with all the manufacturers , not just Honda ......... KTM ,Suzuki and Yamaha and Kawasaki all have valves that zero out for various reasons and there is no time limit for this to happen , you can do preventative things to slow the pace , but valves will go out of adjustment and they will fail no matter the brand or how you take care of your bike , you can only prolong the inevitable , but never prevent it

That said , i switched to Stainless in my 450X and 450R (450R 2 years ago) and have not had to do a valve adjustment since 2006 (on the 450X) , results not typical , but its not the extreme either , Stainless valves and even better valve seats (aftermarket) will prolong valve life more so then the same precautions taken with Titanium valves ( i only replaced the valves not the seats)

So to answer your question .... The R and the X have the same materials and components in the head , they are not made "different" than the opposing model , this was done to simplify parts replacement cost to the manufacturer , all the models use the same parts , its cheaper for manufacturing , it does not mean its the best solution for the consumer , durability wise .........how and when they fail is more a matter of abuse and misfortune rather than intent from the manufacturer , a R that was revved to the limiter constantly will have a greater/quicker chance of a valve failure than a X that is gently trail ridden , but a X that is abused in the same manor as the R will suffer the same fate as the R or vice versa ...............Most people switch to Stainless if they are not serious racers , as the advantage is a few hundred RPM and a slight gain in power , for the "average rider , switching to Stainless valves cuts maintenance intervals dramatically , most people sell bikes for 1 of 2 reasons , either they are upgrading to a newer/better model , or they would rather get a new/different bike to avert the cost of doing the maintenance that is needed to repair a issue either they caused or was just from parts being worn out and needing costly replacement ...if someone selling a bike says "the valves were just adjusted" , it means the valves are wearing or are worn out.........but generally when the valves start to move , its only a matter of time , regardless of the model

Hope that answered your question...

EDIT: Just noticed Ken must have posted , while i was typing my response ..........

[Leardriver]

My fairly worthless perspective on the difference in wear characteristics between the two is:
The X valves lasted longer because the bikes weren't flogged at red line non stop quite as often as an R on a track.

Rpm's contribute greatly to wear. Diesel engines run a long time with redlines under 3000 rpms.

[Aussiecrf230]

Agree with what has been stated above.
To put it in perspective, whereas the Honda gets to a point of not starting, the 5 valve yamaha heads still lets you start them. The few I have autopsied had resulted in the loss of a valve head and pretty much trashing the motor.
Factor in the price of a top end rebuild into the purchase price. If they don't budge you can always keep looking.

[crfsonly]

To Leardriver's point, we often get asked "How many hours will xyz last?" I always reply with, "No two engine hours are created equal." Engine hours are a function of RPM's. Even average RPM's per engine hour doesn't tell the whole story as there's somewhat of a geometric progression of wear the higher the RPM's.

Ken