Page 87 of 87 FirstFirst ... 3777858687
Results 861 to 863 of 863

Thread: Powerplus or Bust, Eh?

  1. #861


    Here's the post-mortem on the front cylinder that seized on stage 4 of the 2018 Cannonball, then ran for 3,000 miles after that. As you would expect, the piston was pretty well cooked.

    The cylinder had some scoring, but mostly it's just aluminum stuck to the cylinder wall. It would probably hone out and be useable.

    And here's the smoking gun. A crack had formed between the threaded holes for the valve plugs. This caused a vacuum leak, especially once the engine warmed up and the crack opened up further.

    This kind of cracking has been known to happen on these cylinders, usually believed to be caused by the original bronze valve plugs that expand at a different rate than the cast iron. I don't use the bronze plugs, but the cylinders did have bronze plugs in them when I got them.

    After the crack formed, the vacuum leak caused that cylinder to run lean and hot, and it seized. It seemed to happen all of sudden, not gradually. The engine was making really good power, then all of a sudden it was not, then it seized in a very short time. After I got it running again, I could see by the spark plugs that the front cylinder was running leaner than the rear. In fact, to get the front plug to read right I had to richen up the carb to the point that the rear plug would get black and sooty. It was a pretty clear indication of a vacuum leak on the front cylinder, but I wasn't able to find the leak with the equipment I had with me. It clearly was not at the intake manifold. A pressure test would have found it, if I could have done that. In the end, what I did to get me through the Cannonball was I went to a tractor supply store and found a hotter plug for the rear cylinder so it wouldn't foul, and ran the carb rich enough that the front plug looked right. You do the best you can with what you've got.

    I'll probably braze that crack up, hone the cylinder out, and use it as a spare. It will be a tedious process due to the fine threads, but it's worth saving the cylinder.

    I'll try to get some pictures of my intake cam followers before I go on the road again. I'm really happy with the way they performed.



  2. #862
    Join Date
    Jul 2012


    Quote Originally Posted by Shaky Jake View Post
    the front cylinder that seized on stage 4 of the 2018 Cannonball, then ran for 3,000 miles after that.
    When you run into a problem while working on a bike at home you can set it aside for a day or two while you think about it, devise a possible solution using your garage full of tools, machine a new part from scratch or order a replacement to be shipped to you, test your solution, and think about it some more if that solution didn't work. If you had planned to ride that bike on the following weekend you simply use a different bike instead.

    On the Cannonball your alarm wakes you before you're ready, you ride all day, then in the evening when you're quite tired you only have a few hours to do all the routine daily maintenance plus figure out what might be causing the problem you had that day and what might possibly fix it, implement the hoped-for solution using the tools and spares you thought to pack plus whatever you can scrounge from someone else who happens to be working late into that particular night like you are, and finally go to bed to get not enough sleep in order to repeat the next day. For 15 days in a row just using a different bike the next day isn't an option.

    As Kevin's latest post shows, a problem so serious that under anything like normal circumstances it would have taken his bike off the road for at least a few weeks was diagnosed and addressed by a trip to the tractor store so that he could continue on for the rest of the Cannonball. Riding a 90+ (or, in Kevin's case, 100+) year-old bike across the country in the Cannonball is qualitatively different than any other experience I've had in 55 years of riding motorcycles. Reading a post like Kevin's gives a taste of the Cannonball but until I experienced it myself I did not have anything like a reasonable appreciation of what is involved.

  3. #863


    On my many pre-16 motorcycle tours, I have had some problems (minor) and seen other people that have had big and small problems (mostly their problems). For the most part, if it is fixable, then it is fixed that evening. The “fixing” is usual that night’s entertainment for the rest of the tour group as they all sit around giving advise (translated to joking and harassment) during the “fixing”.
    Fixes like use a rubber budgie to hold a gas tank in place and epoxy a cutup beer can over the holes in the top of the gas tank from the ripped-out speedometer tank mount when the speedometer drive caught in the rear wheel taking the speedometer with it. Helping with that fix, allowed me to ride a Cyclone on a short 10-mile round trip at high speed down the interstate (per the owner’s instructions) to make sure everything was Ok and did not vibrate for the rest of the tour. Taking parts to the local welder or machine shop for “improvements” before they close and talking them into staying late. From fixing flat tires, to complete motor rebuilds, to re-truing a lower end, to filing of seized pistons to get the “right” clearance, to replacing broken cam followers, and many more repairs. All for the group’s nightly entertainment.
    There are the on-the-road fixes also, to complete that day’s ride, or to completing the rest of the tour. Like cutting up an innertube to make a rubber band to replace a broken intake spring so one cylinder has atmospheric intake and the other cylinder has mechanic intake. Using vice grip plyers to replace a nut that has fallen off the axle. I could go on and on.
    The biggest difference is, we only had to deal with it for 3 to 4 days, not over two weeks like the Cannonball
    While it may be stressful, it is those little things that make the tours rememberable and not just another boring forgettable tour.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts