Monday, July 6, 2015

Too Much Wrenching, Not Enough Riding!

I can't believe it's already July.

Summer came early to Alaska this year. Usually, it's the first week of May before enough ice has melted off my driveway for me to be able to get the bikes out; this year, I was commuting to and from work by mid-April. The weather since then has been phenomenal too, with June being a long series of clear, blue, sunny days with temperatures as high as I've seen them since I moved to Alaska some twenty-odd years ago.

So, of course, I spent most of the month of June laid up with an injury that kept me off the bikes entirely during the best two weeks of the month, and then spent the remainder of the month just commuting back and forth to work. I'm almost recovered now, but as a result, I have only taken the Strom out of town once this summer, for the B.A.C.A. 100 Mile Ride. Sigh...

However, even if I haven't been riding as much as I'd like, I've been making progress on the Cafe Racer project. After blowing the head gasket on the Yamaha triple last summer, I picked up a new engine gasket kit from Athena and rebuilt the top end of the XS750. While I had the engine apart, I borrowed an ultrasonic cleaner from a co-worker, disassembled the carburetors, and cleaned the carbs (again...) to try to solve the high idle problem I've been fighting since I bought the bike. After ultrasonically cleaning the carbs, I noticed a ridge of gum inside the carb where the butterflies close, so I did some heavy-duty cleaning on the inside of the carb and the outside edge of the butterflies with some 1500-grit sandpaper, but still can't get the bike to idle properly (grrrr...). I also tested moving the needle valve clip to the stock position (the center position of the five possible settings), but the bike feels like it lost off-idle response and stumbles upon initial throttle input now, so I'll be moving the needle valve clip back to one setting above stock (one setting more lean).

One minor problem I noted with the Cafe Racer last summer was that the front forks felt rather soft -- not surprising, since I have no idea if the fork oil had *ever* been changed. Consequently, I purchased a set of Progressive 11-1107 fork springs from, and rebuilt the forks this past weekend, which turned out to be a much simpler task than I expected, once I figured out a couple of tricks to getting the forks disassembled:

  1. Don't Remove the Forks Completely:
    To remove the fork guts, you'll need to remove a spring clip in the top of the fork. The service manual says to hold the fork tube in a padded vise, then depress the cartridge inside the fork to pop the spring clip loose. I didn't have a padded vise, but was able to make do by lowering the fork in the triple clamps until only about an inch of the fork stuck up above the lower clamp, then tightening the bolts on the lower clamp. Then I used this tool here...: depress the cartridge inside the fork... I could pop the spring clip loose with a small screwdriver like so:

    NOW go ahead and remove the forks completely for the rest of the work!
  2. Pry Out the Oil Seals from Underneath:
    The next problem I ran into was getting the oil seals out of the fork bottoms. I spent a while trying to dig the oil seals out from the top before finally using the biggest flatblade screwdriver I owned as a pry bar to pop the oil seals out from underneath. Set the blade of the screwdriver under the oil seal, then place the shaft of the screwdriver on the top of the fork. Press down on the handle until the oil seal rotates 90 degrees in the fork, then pull it out with your finger. Easy ;)
  3. Make Sure You Have New Dust Seals:
    I didn't pick up new dust seals before starting on the forks. The dust seal on the right-hand fork looked to be in decent shape, so it probably would be fine, but since the left-hand dust seal is cracked and in pretty rough shape, I'll probably just replace both...once I get a new set of seals...which means I'll have to remove the forks from the triple clamps again in a few days or weeks :roll_eyes:
  4. Don't Forget the Washer Between the Springs and the Pre-Load Spacers:
    Yep, I forgot to install my spacer, so I had to partially disassemble the forks again. Fortunately, this gave me the opportunity to snap the photos above, since I didn't take any pictures at all the first time ;)
  5. Use a Torque Wrench to Tighten the Triple Clamps:
    Otherwise, you end up with a problem like this:

    Yep, I over-tightened one of the bolts and sheared it in half. Fortunately, it was easy to drill out from behind, so tomorrow, I'll pick up four new bolts (might as well just replace them all) and finish up the fork work.

Really, those were the only significant "gotcha's." Everything else was pretty straight-forward. Progressive included a piece of plastic tubing to use to set your spring pre-load with their kit, which means you have to cut the tubing to size for your application. They give measurements for a number of bikes, but unfortunately, the XS750-2D wasn't one of them. However, the XS850 was, and the size recommended for the 850 (1 1/2 inch) was almost exactly the same as the difference in length between the OEM springs and Progressive springs, so I used that. I haven't had a chance to test ride the bike since installing the springs because I can't kick start the bike right now (the aforementioned injury that had me laid up for most of June), and I've removed the electric starter, so kick-starting is the only option for firing up the Yammie. However, once I get a chance to test ride the bike, I'll edit this post with an initial impression on whether or not 1 1/2 inches of pre-load was a good call.

I also might have to revisit the amount of oil I added to the front forks, since I was a bit confused by Progressive's instructions on the subject. After reading and re-reading the instructions, then trying to figure out how to use the Motion Pro fork oil measuring tool, I think I added the right amount of fork oil, but I'm not certain. Again, once I get a chance to test ride the bike, I'll adjust the oil level as required to get the compression and rebound damping reasonable.