Highfive - WRR Athena Big Bore Project

Discussion in 'Thumpers' started by HighFive, Sep 18, 2010.

  1. danceswithcages

    danceswithcages Been here awhile

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    Yet another reason I left Pugetropolis.

    Here in Montucky you can make any vehicle street legal, including quads. Just need a brake light and mirror. :D
    #41
  2. 10Cup

    10Cup Long timer

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    HF, you are definitely the man! This looks like so much fun. I can't wait to see what your opinion of the mod is. Power is most likely a given but what does it do to the mileage and range etc. I know you will document everything and do it well, so thank you in advance.

    Fully subscribed here!
    #42
  3. bpg

    bpg Off Trail

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    I hear you on that - I love my WRR, such that the only real complaint is the abruptness of throttle at walking speeds (especially over really bumpy terrain). I'm spoiled by my tractor-like, 51T rear sprocketed vintage XL250 - it breezes through that stuff with ease (although the WRR obviously kills it everywhere else!:evil).

    Absolutely let me know re: a Dragon ride - fun to chase sportbikes on a knobbied 250, then disappear into the woods for some superb western NC dual sporting!:clap
    #43
  4. cyborg

    cyborg Potius Sero Quam Numquam

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    #44
  5. HighFive

    HighFive Never Tap-Out

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    Good info, Sandman. I have no idea where the factory sets the valve clearance on the WRR when new. Somebody please open their brand new WRR and take a measurement for us.....purdy pleeeeeeease!

    I'll cover my valve check shortly.....standby.


    Aaaahh.....The Krabill joins us. Fashionably late, of course. :freaky

    Yes indeed, Cyborg. Your baby was "spot on" smooth as a baby's butt, when I rode it 2 months ago in the Great PNW. :deal Or, should I now say, "not so great pnw". Husa just can't be a no-no. Say it isn't so.

    Thanks to you, I know its possible to achieve a buttery smooth take-off, with a Power Commander unit. But wait....mine will be better than yours, my friend.
    :wink:

    Hey...Welcome Home, 10Cup! What an amazing trip you just had! ! ! ! [​IMG]
    And yes sir, you are right. This is a FUN project which ain't finished yet.


    Now then, since everyone is so antsy about the valve specs, I'll make that my next installment. Coming soon....

    HF:thumbup
    #45
  6. Krabill

    Krabill Long timer

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    Sorry for being late to the party . . . I was out ridin' :ricky



    Here now though, boss :devildog
    #46
  7. a1fa

    a1fa Throttle Jockey™

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    In, as well!
    #47
  8. cyborg

    cyborg Potius Sero Quam Numquam

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    Smoother than a baby's butt eh? :lol3 Waiting to hear about it.

    In the 'Berg's only the 2011 FE 570 will be sold as 50-state street legal, the others will be clearly marked as "Offroad Only" on the MSOs.
    #48
  9. HighFive

    HighFive Never Tap-Out

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    Geez.....that Washington State rule sucks! Pretty soon, this is all you're gonna be able to ride up there, Cyborg:

    [​IMG]

    Better grab one, while they are still cheap!

    Now then, enough with the [​IMG]

    Let's get back to The Land of the Free......down here in No Man's Land....where you can ride anything you want ANYWHERE!

    HF
    #49
  10. Mr. Fisherman

    Mr. Fisherman PROUD 2B Riff Raff!

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    Not gonna fly in Warshington... No helmut, shoulder pads, high vis vesteses and no note from your mother.... no endorsment from the governors safety commission on extension cord inspection and a stamp to certify the monitor is in the right spectrum for eye strain and protective glasses in addition to a stamp certifying there is no lead in the paint.... and safety shoes... and stuff.... just send them your money and wish they provided an envelope and postage to send it in. And wear gloves :lol3
    #50
  11. HighFive

    HighFive Never Tap-Out

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    :poser
    #51
  12. HighFive

    HighFive Never Tap-Out

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    So, everyone is dying "to know"...... what was my valve clearance? Let's check and see!

    First thing, you need to get yourself one of these nifty, old-fashioned, gadgets:

    [​IMG]

    This is a plain 'ol Feeler Gauge which you can buy at most any Auto Parts store. Just make sure you get one that has both metric & english measurements indicated on the individual gauges (as you can see in this photo). It makes the job a lot easier if you have more than one bike. Some manuals spec clearance in "inches", while others list "mm" (millimeters). That way, you don't have to keep converting your measurements. You'll be confused enough trying to remember "more is less"...."bigger means smaller" if & when you are figuring out how to interpret your valve clearance adjustment.

    One the left sidecase, remove these two plugs to expose the "timing marks":

    [​IMG]

    At first, I was alarmed to discover oil in here:

    [​IMG]

    Thought I had a main seal leak in on my crank centercase. Didn't think the electrical power generation station (magneto / alternator .... gets called all kinds of names) should be spinning in a bath of oil. I'm so used to working on 2-strokes, all my life. But the Krabill assured me, all was well. Same thing on my mighty KLR (which I've just not noticed before). And now, I see the O-ring seals in the caps....in this photo. So, I can sleep ok.

    Remove the Spark Plug to relieve compression from the Head. Then, using a sprocket wrench on the mag nut (in the big hole) slowly turn the crank counterclockwise until the "single" timing mark aligns with the single mark in the side of the small hole.....like this:

    [​IMG]

    Kind of fuzzy and hard to see, I know. My little camera doesn't take macro shots (close ups) very well. But you get the idea. CAUTION: there is another mark on the mag (in that small hole) that comes around just before the little single timing mark. It looks like an "H". I'm not certain what that one is for (someone else can chime in to explain). But, don't use that one. Align with the single mark that follows it.

    Once aligned, look up top at the camshaft sprockets. There are alignment marks stamped into those, as well. In this position, which should be "Top Dead Center" (TDC) of the Compression Stroke, all 4 of these marks should be aligned parallel to the top of the Head.....like this:

    [​IMG]

    Look closely and you can see 3 of them near the edge of the head.....along a horizontal line. The 4th mark is off to the left in the shadows (out of sight). Study these postions and maybe even take photos for yourself, before you remove your camshafts from the engine. You will have to set all these timing marks back to this exact position when you put the engine back together....or it won't run right, if it runs at all. Actually, you could seriously damage something (like your valves) if you fail to do this correctly upon reassembly. I'll cover this in detail upon reassembly.

    Now, look at the right side of your motor and the camshaft lobes will look like this:

    [​IMG]

    Notice each lobe is pointed to the outside (away from center....opposite of each other). This is the target we are after. The valve clearance must be measured at TDC, with the camchain still under tension, like this:

    [​IMG]

    We measure the gap between the cam lobe and the lifter beneath. Find the feeler gauge that just slides in between with some resistance. Usually, the next larger size won't fit, and the next smaller size is too easy (no resistance). Read the number on that gauge and right it down on a sheet of paper. Draw a little diagram so you know which valve position has which measurement (Left Intake, Right Intake....Left Exhaust, Right Exhaust). The Intake valves are at the back of the motor on the airbox side, and the Exhaust valves are at the front of the motor on the pipe header side. So, in the photo above, I am measuring my Right Exhaust valve clearance.

    Next, compare those measurements to the specified range listed in the Service Manual.....which is this:

    Valve Clearance (cold)
    Intake 0.13 - 0.20 mm
    Exhaust 0.23 - 0.30 mm

    And now.....drum roll..............................................my measurements were (at approximately 8,000 miles):

    Left Intake 0.13 mm
    Right Intake 0.13 mm

    Left Exhaust 0.23 mm
    Right Exhaust 0.23 mm

    I could force a 0.15 mm into only one of my Intake gaps, but decided it was much too tight to be correct. So, I accepted that both were 0.13 mm in clearance.

    So, every one of my valves were sitting right on the lower limit. [​IMG] That means they were on the edge of being too tight. Valves get tighter as the parts were down. When you adjust valve clearance, your goal is typically to increase the gap to somewhere near the larger end of clearance.....so, they can slowly wear down toward the lower limit again.

    The question of the day: Where did the factory set my valves upon initial installation? They don't say. If they were set dead on this lower limit, then my valves haven't moved a tiny bit. If they were set in the middle of the range, then they have worn some (which would be my normal expectation). If they were set at the upper end of the range (which is where the manual tells you to reset them to), then they have worn a lot in just 8,000 miles. I can tell you the factory used shim pads with .01 mm increments to get it perfectly where they wanted it. For some reason, we are only allowed to work in .05 mm increments, because that's all the motorcycle shops ever seem to have on hand.

    The Answer: Who knows! I ain't got a clue.

    What I do know, is I do not want my valves running "too tight". Nope, nada, no way. Mine were currently "in spec", so all was fine. But would it stay that way? For how long?

    So, I'm going to adjust mine right here and now.....because this is definitely something that would keep me awake at night....pondering....and you know how I feel about that. I'd have to start popping sleeping pills to get a good night of sleep.

    Next up, we'll pull the shim pads and have a close look at them.....then go hunt down some new sizes. Refill your popcorn!

    HF :thumbup
    #52
    ACR likes this.
  13. Nice_Rumble

    Nice_Rumble Long timer

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    You make it look easy to the point where I might attempt to check valves on my other bikes as they don't have such a long service interval. I always let the shop technicians handle this but they don't have the same interest in the machine that I do.
    #53
  14. HighFive

    HighFive Never Tap-Out

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    Easy peasy to check the clearance. A little harder to adjust them....but not too hard. We'll go thru that process shortly.

    The Krabill taught me how to do this on my KLR a few years back. If an old shaky handed fart like me can learn to do it, with confidence....no less, then anyone can. It doesn't even require very many wrenches, and no special tools.

    HF :deal
    #54
  15. Krabill

    Krabill Long timer

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    Well . . . maybe a 1/4" torque wrench :deal
    #55
  16. Pigford

    Pigford British

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    STOP - Do NOT bother doing the clearances now :huh

    You should redo them AFTER the rebuild, as new head gasket & retorquing the head may well lead to minor distortion & effect the clearance measurement!. ALSO, the clearances are best re-checked with the lobe pointing 180 degrees away from the shim surface - in line with the axis of the valve stems.
    #56
  17. Throttlemeister

    Throttlemeister Long timer

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    Did I hear Helicoil?







































    :hide

    Looks like a great mod for the 250, er around three something.
    #57
  18. HighFive

    HighFive Never Tap-Out

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    [​IMG]

    Interesting comments.

    The entire valve train is contained within the Head Assembly. So, I'm not sure how gaskets outside the Head Assembly would affect the clearance. This is a new one to me...?? My imagination can follow your idea of some "distortion" a little bit. But, I'm still trying to work this one out in my head....visually. I'm all for learning something new.

    Regarding the procedure for checking the clearance, I'll say that I believe I got it right.....at least according to the official Yamaha WR250R/X Service Manual....if that's worth the paper its printed on. :lol3 Sometimes maybe they are not.

    Page 3-4 "Adjusting The Valve Clearance" states the following:

    Valve clearance adjustment should be made on a cold engine, at room temperature.

    When the valve clearance is to be measured or adjusted, the piston must be at Top Dead Center (TDC) on the compression stroke.

    Align the TDC mark of generator rotor with mark on rotor cover.

    Measure the valve clearance with a thickness gauge.

    Out of specification --- Adjust.


    So, I'll blame it on the manual first. Then, on the Krabill second. This is same way he taught me to do the KLR motor....same way the KLR manual instructs....and its always seemed to work correctly.

    But then, I am no professional mechanic. I probably even break a lot of the mechanic's code....if there is one. But I'm trying hard to do it right. Really, I am. Scout's honor!

    HF [​IMG]
    #58
  19. kawagumby

    kawagumby Long timer

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    Great write up! Regarding the valve clearances...as I noted earlier, on the WR250f's the factory clearances are very tight when new, right at minimum. If the street bikes are that way too, as another poster noted, then it is likely the WRR's are set up tight also. Why tight? Valve opening duration is maximized. Larger clearances might also increase wear rates -

    About the abrupt throttle....mine is smooth and progressive, stock. It is no more grabby than any other bike I've owned. My bike has no flat spots anywhere either. The only mod to the bike I've done is the air box flap removal. I wonder if the throttle issue is a production run thing?
    #59
  20. rufus

    rufus We're burning daylight...

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    A good tip for making sure you are up on the COMPRESSION stroke it to watch the valve train while you spin the motor. AFTER the intake valves open, then go to your timing marks. Compression stroke is in between the intake and exhaust valves opening (and closing) cycle.
    #60