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Minimise VALVE Post Remedy ?

By Puttikan,
in CRF250X

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Puttikan

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It is in this forum and the R, valve post after valve post. Same question after same question.

So to compliment Heckler's sticky and to answer a lot of the most popular questions that posters ask aside from Hecklers "How Too" I propose to ask the following:

What other info could some knowledgable, kind TTer come up with to answer the common valve questions in one post.

It could end up being like the Readers Digest of Valves. Some examples are how long between checks, other options etc.

If this is a good idea maybe the answers could all be submitted here then that is organised into one post and then sticky'd alongside of Hecklers.

How about it, we need just one more almighty valve post.

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Veteran

gunner150

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Posted
It is in this forum and the R, valve post after valve post. Same question after same question.

So to compliment Heckler's sticky and to answer a lot of the most popular questions that posters ask aside from Hecklers "How Too" I propose to ask the following:

What other info could some knowledgable, kind TTer come up with to answer the common valve questions in one post.

It could end up being like the Readers Digest of Valves. Some examples are how long between checks, other options etc.

If this is a good idea maybe the answers could all be submitted here then that is organised into one post and then sticky'd alongside of Hecklers.

How about it, we need just one more almighty valve post.

Ya I agree i'm getting sick of people not using the search and asking "how do i check my valves" or "are there really valve problems"

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Grand Master

Hit_the_set

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Valves

F.A.Q. and some of the answers in no particular order. This is my expressed opinion on how to treat a CRF250’s common valve questions. I’m in no way responsible, or any one else from TT responsible for any issues that are caused by this thread.

If you have any questions that are valve related please post them here and if it’s a good question I’ll edit the post and add them to here for every one to read and learn.

If you have a question that’s not valve related please do a search on the main bike thread and I’d be willing to bet you get your answer.

1st step is to take care of your bike. Maintenance on this bike is a must. Keep a strict regimen on taking care of your two wheeled adrenalin machine.

Change the oil regularly on both side’s transmission and engine. I change my oil after every race and after about 10hrs of practice or trail riding. This might seem excessive but that’s just what I do. If you don’t agree please follow your owner’s manual.

I clean my air filter just about every time I practice or trail ride. Just take a look at it after your done riding, and you can tell if it looks bad clean it. I clean it after every race. It’s worth it to me to do that to help maintain my motor / carburetor to stay in good working order. This is just what I do you don’t have to agree or disagree. If you don’t agree please follow your owner’s manual.

Thanks 40oz for the suggestion

I believe that one of the 1st thing to do when you get you bike is to check the valves before break in and after break in. There is a possibility that some bikes come from the factory with valves out of spec.

Q1. How do I check my valves?

A. Use your owner’s manual and this post https://www.thumpertalk.com/forum/showthread.php?t=179775 it’s a very good post will all the correct steps. It will save you a lot of money. One thing that I’ve fund very help full it to check the exhaust valves like this http://i14.photobucket.com/albums/a301/hit_the_set/Valve1.jpg I’ve been told that I have too wide of feeler gauges but I believe that this is much easier than trying to bend or purchasing bent feeler gauges.

Q2. How hard is it to check my valves?

A. It’s very easy to work on your valves the most important thing to do is to take it step my step. Take your time and it’ll be a very process.

Q3. How often should I check my Valves?

A. You usually want to check your valves every 10 hours if riding.

Q4. What is the spec for valve clearance?

A. The spec for you intake is .005 with a variance of ± .001 which means that you can have .004, .005, or .006 when you measure your intake. The spec for the exhaust is .011 with a variance of ± .001 which means that .010, .011, or .012 is acceptable.

Q5. What shim size should I use?

A. Go to here http://home.earthlink.net/~larrygarrido/CRF250%20Shim%20Guide.xls and download the shim calculator. (Note: this is for the CRF250 only the CRF450 is different. I have one that I’ll give you if you let me know)

Q6. Where can I get shims for my bike?

A. You can get them at your local dealer or you can order a shim kit from TT store go here http://shop.thumpertalk.com/catalogs/Parts_Unlimited_ATV_2005/default.asp?p=785

Q7. Do I need to put any kind of adhesive on my valve cover gasket when I reinstall.

A. I use a very small amount of engine assembly grease in the groove of the valve cover just to help it stick until you get it on. I think that using an adhesive will eventually eat away at the gasket.

Q8. I re-shimmed my valves the other day and went on two rides with about 10 hours combined riding and I checked my valves again and they are out of spec. Can I re shim and ride it some more or do I need to get new valves?

A. As soon as your 1st re shim you should start saving your pennies because head work is in your future, once the valves start to move they usually don’t stop. You can re shim but it’s just a Band-Aid and they fall off and will re expose the wound. If you are having issues with keeping the valves in spec you need to seriously think about new valves. That topic is an entirely different thread. To be done at a later time.

Q9. I checked my valves and they are at zero clearance what shim should I put in?

A. At this point it’s a guessing game. There is no way to tell what shim will need to be put in. This is where a shim kit comes in handy. You have to make the best intelligent guess at this point. Put in a shim that you think will work and check if you are getting any clearance. I would suggest going 2-5 sizes off from where you are at and re assemble you should be able to find out what the clearance is with that shim. With that information you can find out what the correct shim is with the shim calculator http://home.earthlink.net/~larrygarrido/CRF250%20Shim%20Guide.xls .

Q10. Are the valves really a problem on this bike?

A. I believe that the valves are not really a problem on this bike. Every four strokes valves will eventually go south plain and simple. I don’t spend a lot of time in the other bikes forums but the time that I have I’ve seen the same questions over and over. Valves wear out. There are ways to help resist the premature wearing out of valves on these bikes but sometime it’s just bad luck.

Q11. Will a 2006 CRF250 head fit on my 2004 or 2005 CRF250?

A. Yes, it will fit. The 2006 CRF250R head has some changes to it but it will fit. The new head has some horse power increase from the two previous years. As far as the changes on the head I’m not sure of all of them because I don’t have one yet. The valve seat material seems to be holding up better on the 2006 models with some extended valve train life, but I don’t believe as of February 2006 that the bike has been out long enough to really tell the true tale of its new and improved head design.

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Dan CRF250

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i read it threw and it sounds pretty intelligent and very well spoken.

One thing i did when my valves went to zero was when i replaced my shim i went with one that was .007 smaller then the one that was on my zeroed valve. this brought the valve up to .006 clearence, your valve cant wear anymore if it has no space to wear. when your valve is at zero, its basicaly floating.

^^ this is just a good place to start if you dont have a shim kit and are ordering seperate shims.

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  • 1 month later...
Proficient

Tuner

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I wish something like this would work...........the constant valve thing really gets old! Unfortunately, unless you can make it a default thread whenever the word "Valve" is used..........these folks are never gonna' use it................it's been beat to death, and still nobody uses either the "Sticky" or search........good luck!

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DRH

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To your knowledge, has anyone established the longivity of the valves on a totally stock bike verses the ones on the modified X's Has the rejetting to a leaner condition to inhance the power advanced the wearing of the valves? I would be curious to know. My 05 X at this point is totally stock, Just about about ready for its third set of tires, and my valve clearance has not changed since day one. I estimate about 750 miles on it.. I have all the parts to re-jet but have been relunctant to do so...Thanks

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Experienced

MauiMoto

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Re: Is it Seats or is it Valves - That is the Question ?

from post earlier this year----

Quote:

Originally Posted by MauiMoto

Just got my 05 feb.issue of 'dirt rider' with continued article on valve trains by Eric Gorr ---page 107 quote---when the engine is shut off, kick it over until piston is at top dead center. If any of the valves are open, moisture in the air will condense on the valve seat, causing corrosion. Thats not a problem for steel valves but a rough seating surface will damage the oxide coating of a titanium valve---unquote.

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