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Jim Hultman
Jim Hultman
Minnesota, US
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Thread Like Summary
Allan G, leon bee, wbabojo
Total Likes: 3
Original Post (Thread Starter)
by Tracey Spear
Tracey Spear
Here's an update on my '69 Thunderbolt project:

The first shake down ride ended with a damaged valve train. A rocker and a couple of push rods later and I was able to take it out today for a second ride. The first time out I had, what I thought was a Amal issue, but a forum member taught me that a lot of carb issues are electrical. Which was very helpful advice since I had incorrectly built one of the spark plug connectors. This time around the engine pulled better and did not crap out at mid RPM. I did not attempt to push to max rpm, but I think I assembled the intake valve train correctly this time and the electrical carb issue seems resolved. The engine over all sounded much better, fingers crossed.

I need advice troubleshooting and sorting out the shifting issue which remains from the first ride.
In my previous post about ride one, the forum suggested a weak shift lever return spring. The only thing I changed so far was the position of the shift lever. I thought I might have installed it a bit low and perhaps was riding with my foot.

Again Neutral to 1st was a solid clunk, Neutral was easy to find. 1st to 2nd was also nice and solid. The shift from 2nd to 3rd nothing.
In the last post someone mentioned that perhaps the lever isn't returning positively. To test this I very lightly pressed down on the shift lever then up shifted to third. It was very sensitive and I did manage to hit third once or twice. Even then it took three or four attempts to get the shift right. I didn't have room in the neighborhood to go for 4th.

Now that I have it running. Are there more test I can conduct while riding to better troubleshoot the issue?
Do I need to pull the outer case and have a look at the _______? Return spring?
Do I have a problem deeper in the transmission.

Please Advise and Thank You

Gettin' closer. grin
Liked Replies
by Mark Z
Mark Z
Tracy, are you absolutely sure that the shift lever is not slipping on its shaft? The slippage can be subtle and hard to detect. It's also a common problem on BSA twins because the splines are so fine.
1 member likes this
by Tracey Spear
Tracey Spear
Well, I guess I sorted that shifty business out. Though it is unclear to me how, I can now shift cleanly into all four gears.

I removed the outer cover. Looked intently at the shift lever return spring. Then I removed the stop plate and spring. And, just because, I turned the spring over. Then I looked intently at the spring for a minute. I reassembled everything, took it for a ride and low and behold! I'm shifting in all four gears.

I can't explain how reversing the spring fixed it, I'm just happy to be one step closer to bringing this beast back from a long 35 year slumber.

With 3rd and 4th available I left the neighborhood for trips up and down the feeder road where I could stretch er legs a bit. Everything felt fine. 'Cept for a bit more top end noise after I got it really good and warm. I'll adjust the valves and take it out again tomorrow.

Oh! and the 51 year old Smiths speedo doesn't seem to want to register much over 40 mph. But Officer, I swear, I was only going 40......

Teaching my body to learn to operate a properly configured motorcycle is more difficult than I thought. Shifting with right foot is coming along. Teaching that left foot to brake is more of a challenge. Even after not riding for 30 some odd years, that brake reflex that my right foot developed is hard to unteach and I've downshifted right when I should have been on the brake left. Learning curve.

I recon learning to stop properly is a good reason not to venture forth into traffic until both the bike, and I, are sorted out.

Tomorrow I'll see if I can't figure a way to get the throttle cable sorted out. Then I can warm it up and tune the carb a bit. I haven't gone through the fine tuning procedure on the Amal Premier yet.

Thanks all for the advice.
1 member likes this
by Tracey Spear
Tracey Spear
Thanks Allan

Based on your advice above there is a new spring on the way. I had considered returning it. Perhaps I should hold on to it.

I appreciate the advice.
1 member likes this
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