2013 CRF250R Valve Adjustment
  • stavendirtbike
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    2013 CRF250R Valve Adjustment

    by stavendirtbike » Sun Apr 21, 2019 6:10 am

    13' CRF250R. Unknown hours. I bought the bike used 4 years ago. Has an FMF 4.1 with the Megabomb and I was *told by the previous owner with no paperwork to support* that it has a Hi-Comp piston. Got a fantastic deal on it and it has ran great since but lately, it has been getting difficult to start, especially if stalled while hot. Bike runs fantastic otherwise.

    All the valves except for the right intake are out of spec (tight).

    Left Exhaust: .008"

    Right Exhaust .009"

    Left Intake: .003"

    Right Intake: .004"

    I will shim accordingly but what dictates when we should stop shimming and do a valve job?
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    JimDirt
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    Re: 2013 CRF250R Valve Adjustment

    by JimDirt » Sun Apr 21, 2019 7:13 pm

    Welcome to the site !! \:D/

    Basically when the valves start moving , it is inevitable that it will need a valve job , the time frame , is unpredictable , it can last several months , or even a season on a shimming , or it can change weekly , there is no "it will take this long" scenario , too many variables , but at .003 you are about at the limit , at .002 , it will most likely be popping and backfiring and hardly able to run at all , once it hits .000 , there is no adjustments left , and you will have no option but to do the valves as the bike will most likely no longer run at all .... , the Exhaust are not real bad and 4 on the other Intake is tight , but not bad , some people even purposely shim them to that , the Exhaust will last longer than the Intakes will at the decreased gap , the face does not wear like the intakes do , you can usually get double the life or more out of the Exhaust compared to the Intakes

    As to the piston , without paperwork , there is no telling on the piston till you tear it down , its his word , and that is all you have .... if you don't know him , then its a crapshoot , it either has one , or he said that to make the sale thinking you would not check , or ask , if someone else rebuilds it....... either way , it won't matter , when the time comes , you will put in what you want or can afford , so its irrelevant as long as you are happy with the performance of the bike (minus the valve issue) ..... , and 4 years is great on a piston , depending on the amount of riding you are doing and the type of riding (trail/track/etc)
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  • stavendirtbike
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    Re: 2013 CRF250R Valve Adjustment

    by stavendirtbike » Fri Apr 26, 2019 6:02 pm

    Thanks JimDirt.

    Well I am noticing an issue here with the exhaust valves. Take a look at the photo below. Notice an issue? Hopefully it posts:

    Image

    The required valve shims are level with the top of the valve. In fact, the Left side valve with the calculated required shim is even a tad LOWER than the top of the valve.

    With this there is no more adjustment. The feeler gauge at this point just contacts that rocker arm and the valve itself.... no contact made with the shim.

    I was able to get the right side exhaust valve from .009" to .010" so that is in spec (but at the limit). The left side is a no go. Can't get any better than .008", even with the smaller shim because again, the shim isn't going to make contact with the feeler gauge.

    Thoughts?
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    JimDirt
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    Re: 2013 CRF250R Valve Adjustment

    by JimDirt » Fri Apr 26, 2019 8:20 pm

    I am kind of seeing 2 things going on (at least from what I see in the picture angle) , it looks to me like the left Rocker arm contact point is worn , and (again this could be just the angle) it looks like the right spring retainer is different from the left , but I think the right side rocker looks worn to me , which would mean the rocker assembly would need replaced , but also the different spring retainers could also be causing a issue ,,, take the buckets off the Intakes , and look at them , if they are different from each other (left to right) then I would think that the head was redone and someone crossed 1 of each (1 In/1 Ex)spring retainers from Intake to Exhaust , as they are different from each other and if one is on the wrong valve (a Intake retainer on a Exhaust retainer , then it could cause the issue you are having ... and/or the right Exhaust valve is worn and that would make it taller which would take away the gap just as the Intakes do when the valve face wears and the valve sinks into the seat causing the gap to diminish , but if you are saying the rocker is touching the retainer then that falls back to the wrong retainer on the right Exhaust valve .... :-k 8-[
    02 CRF450R
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    Weiser , Idaho
  • stavendirtbike
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    Re: 2013 CRF250R Valve Adjustment

    by stavendirtbike » Fri Apr 26, 2019 8:54 pm

    I am kind of seeing 2 things going on (at least from what I see in the picture angle) , it looks to me like the left Rocker arm contact point is worn , and (again this could be just the angle)
    Possibly, I don't have a new one to compare to but will try seeking some images. With that side I would think if the contact point was worn then I would have less of a tight clearance issue (due to worn rocker).
    I am kind of seeing 2 things going on (at least from what I see in the picture angle) , it looks to me like the left Rocker arm contact point is worn , and (again this could be just the angle) it looks like the right spring retainer is different from the left
    Will look at this tomorrow and pull the intake buckets to compare.
    but if you are saying the rocker is touching the retainer then that falls back to the wrong retainer on the right Exhaust valve .... :-k 8-[
    The rocker is NOT touching the retainer. The feeler gauge touches the retainer instead of the shim since the shim is just about parallel or lower than the retainer. Any shim size lower than the current ones will not change the readings one bit since the feeler gauge will always have the same contact with the retainer.

    With that said, I did try something a moment ago. I trimmed a spare feeler set so the width was that of the shim, no wider. Now, I am able to position the feeler so it only touched the shim and NOT the retainer. It seems my clearance with this method is in spec at .010".

    Without knowing any history on the bike it is tough. IF I find the retainers aren't mixed up, I am going to run it with the current shims. I was able to get the intake valves in spec easily.

    Fact is, to be 100% confident with the longevity of this bike, the head will have to be re-worked. With that of course I would definitely want to check the piston/rings/cylinder and most likely replace the piston/rings. With that there is several hundreds already, would be stupid not to do crank/lower bearings and associated parts. Turns into $1000+ easily on an already 6 year old bike.

    An OEM crank for this bike is $300. To put it in perspective an OEM crank for a 2007 CR125 is $150.

    Me thinks I may be riding a potential ticking time bomb. I do very much miss the smell of premix!
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    JimDirt
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    Re: 2013 CRF250R Valve Adjustment

    by JimDirt » Fri Apr 26, 2019 9:18 pm

    My bad on the interpretation of what you said ..... yea I would check the retainers just to be sure , I actually use specific motorcycle feeler gauges because they need to get into tight spaces , I highly recommend these ..
    https://www.crfsonly.com/catalog/produc ... ts_id/5034
    02 CRF450R
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    Weiser , Idaho
  • stavendirtbike
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    Re: 2013 CRF250R Valve Adjustment

    by stavendirtbike » Sat Apr 27, 2019 6:55 am

    After reading through some stuff online, it seems several folks like to run a tad tighter clearance on the exhaust valve of around .008". In fact, I read a few unfortunate mishaps of shims falling out of the retainer when closer to .012. Of course there are too many variables with that (were they installed correctly, was timing correct etc).

    Not trying to justify what I have going on since I really hate deviating from factory specs but the bike did run great prior to wanting to check the valves, just somewhat difficult starting. I have an Eddie Sisneros ECM tune waiting to install in the bike once I button everything back up. He claims his tune to help with the starting issues so maybe I luck out for the season with that.

    Bike has been great but to honest I think I am going back to 2 strokes. I am not new to the 4 stroke world. I completely rebuilt RMZ250 and YZ250F engines top/bottom doing everything myself except for headwork (used MX Time for that). The prices of these bikes go up and up.

     Gonna ride this bike rest of the season and off it.
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    JimDirt
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    Re: 2013 CRF250R Valve Adjustment

    by JimDirt » Sat Apr 27, 2019 2:35 pm

    As long as nothing is "hitting" then you will be fine , as far as the 2 stroke vs 4 stroke thing goes , I really have not spent any more money on my 450's than my buddy does with his CR250 (2 stroke) , I have never had to replace a crank (as long as there within spec for clearance , etc.) and no valve has hit a piston (about the only major reason to replace a crank) , I have done the Stainless intake valves , and not had to adjust them since (replaced them in my 450X in 2006 and my 450R in 2015) , my X is on the original piston , my R was fresh when I got it in 08 and I just replaced the piston in 15 with no issues .... granted , the 250's rev more and wear faster , but I do not find the maintenance much more in parts or cost than what it takes for a 2 stroke , now if a shop is doing everything , then you can end up with a $1500+ bill with a 4 stroke , but I spent less than $200 to replace valves and $165 for a JE piston , and $60 for gaskets .... that's about it ..... ;)
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    Weiser , Idaho

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