Pinion Runout

Discussion in 'Engine, Fuel and Exhaust' started by 90FXRS, Aug 30, 2015.

  1. 90FXRS

    90FXRS Junior Member Contributor

    419
    28
    6
    Someone was asking a question and I really don't know so I'm asking everyone on here. Do you need to remove the primary components to free the crank when checking run out?

    He's wanting to change to gear cams. When I did my motor it was disassembled. Was able to move the rods through the top of the cases.

    Since there's not really any tension on the primary I don't see why it needs taken out. I can see why it would be easier to turn but I'm figuring out it in 6th gear and roll the tire. This would put tension in the primary but you should still see it.....right or wrong?
    [​IMG]
     
  2. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    5,456
    133
    196
    I've never checked the runout but your procedure seems to be the way to go. Take the spark plugs out and the motor should be pretty easy to turn over.
     
  3. dolt

    dolt Senior Member Contributor

    1,815
    83
    206
    Your post title is "pinion" runout so I assume you are checking runout on the pinion side, not the primary side and the question is whether or not it is necessary to remove the primary drive to check pinion runout? If that is what you are asking, the answer is no.

    Some check pinion runout with the cam plate in place but it really should be checked with the cam plate, etc. removed as shown in the attached photo. The general rule is that if runout in excess of .003", one should avoid gear drive cams.

    If runout checks out and your friend decides to install gear driven cams, photos of checking inner and outer gear lash are also attached. JMHO, but with the later hydro tensioner/roller chain setup, there is really no need for gear drive cams; the later OEM setup works very well.

    You may know all of the above already and, if that is so, apologies; just trying to help.:s
     

    Attached Files:

  4. 90FXRS

    90FXRS Junior Member Contributor

    419
    28
    6
    One more question. When we're done with the pinion check, to get the gears installed properly, just roll the motor to where the dots on the pinion gear and cam drive gear line up and call it good?
    [​IMG]
     
  5. Jack Klarich

    Jack Klarich Expert Member

    18,544
    153
    399
    Unless it is an EVO, you have to time the breather also
     
  6. 90FXRS

    90FXRS Junior Member Contributor

    419
    28
    6
    It's a twin cam. Since we will be rolling the motor around a few times to check the runout, I was just wondering. It's been quite sometime since I've been inside a camchest. I didn't know if you could get things out by 180 degrees. I remember the gear on the pinion is keyed and the other gear aligns on the dots at about 10 o'clock on the pinion.
     
  7. dolt

    dolt Senior Member Contributor

    1,815
    83
    206
    The inner gears must be aligned first; dots aligned. If they are installed correctly, the two dots on the face of the cam shafts will be pointing at each other and horizontally aligned. Once that is done, the rear cam outer gear will only fit one way and the dot will be at about the 5:00 position. Rotate the crank via the rear wheel until the pinion gear can be installed with that dot aligned with the rear cam gear dot. This will be trial and error since the crank must be rotated while the cams do not turn. The rear cylinder is the #1 cylinder and if the inner gear cam dots are properly aligned and the outer cam gears aligned as shown in in the attached photo, the crank and cams are in time.:p
     

    Attached Files:

  8. 90FXRS

    90FXRS Junior Member Contributor

    419
    28
    6
    Dolt, thank you for your help. I've got the cams installed in the plate, they line up dot to dot. So your saying as long as the gear dots line up in the picture below all is good? It doesn't matter where in the stroke cycle the front or rear piston are at, as long as these dots line up all is well. I forget which one is keyed. I plan on keeping track of how many times I rotate the tire. Haven't had mine apart in years. Going to get into the other bike shortly. Just getting everything ready. BTW, this picture is what is inside of mine. Woods TW9B-G cams on the other side.
     

    Attached Files:

  9. dolt

    dolt Senior Member Contributor

    1,815
    83
    206
    If the inner gear dots are aligned, as I previously posted, the dots on the face of the cam nose should be pointed at each other and aligned. If that is the case, aligning the dots on the gears as shown in the picture should put the piston in the rear (#1) cylinder at TDC. In that configuration, all is good.

    The neither of the outer gears are keyed. The nose of the rear cam is splined with such a pattern that the rear cam gear can only be installed one way. The pinion gear has a "flat" and can only be installed one way.

    One other suggestion, the oil pump needs to be aligned. The procedure for aligning the oil pump is to install all four fasteners loose so the pump and gerotors can move around. Rotate the rear wheel in fifth gear while tightening two of the fasteners at opposite corners finger tight. While continuing to rotate the rear wheel, slowly tighten with a wrench. When the pump is secure, tighten and torque all four fasteners.