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Old 10-04-2009, 12:31 PM
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MikeJ MikeJ is offline
Motorized Bicycle Senior Member
Join Date: May 2009
Location: Colorado Springs
Posts: 82
Default Re: Anyone had this problem?

Hi Addicted -

You asked, "So, has anyone ever had this happen? Why would it have come loose in the first place? Will it likely happen again?"

Answer: YES! Twice now to me! And I am prepared for it to happen again a long way from home.

IN MY CASE.... There seems to be a sequence of preceding events. When riding, I noticed a long stretch (maybe a couple of hours) of metallic "pinging" sound, as if the piston was smacking the cylinder head. Then I suddenly lost total power to the drive wheel, even though I could rev the engine (until I shut the engine down; then the engine would not turn over when attempting to start it).

I took off the right cover, just like you. In both cases, the screw you speak of completely loosened itself and the woodruff key fell out of the shaft. The application of blue Loctite from the previous event did not hold; maybe it softened with heat over time. Without that woodruff key, the 20 tooth sprocket cannot turn, though the crankshaft does.

With tools that I carry, I reassembled the sprocket along side the road. I was 55 miles from home at the time. The second time I reassembled, I put a dab of gear grease found in the gearbox on the threads. It is too early to tell if that will help. Upon reassembly, that "pinging" sound did not reoccur.

The woodruff key (the original) is beat up and severely deformed. I need to order a couple more, and maybe a new 20 tooth gear as a backup. I replaced the screw once just because the original one was beat up from the factory.

Expect this screw loosening to happen again. Loctite is not the final answer. Maybe check before each ride for a while. Periodic inspection and having tools available to fix along side the road is in your best interest. Hint: take a clean cloth with you. Spread it on the ground under the engine before you open the gearcase. If you lose that woodruff key in the grass and don't have a spare, you will be peddling. In my case, if I have to call ladyfriend for help, I owe her two expensive dinners. Two dinners will buy a lot of support parts!

760 miles to date. 65 miles after the second loose screw event.

Last edited by MikeJ; 10-04-2009 at 12:45 PM. Reason: Added content
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