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Old 11-23-2014, 05:56 AM   #1
wardie OP
2 Wheel Power Hour
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Joined: Jun 2008
Location: Youngstown, Ohio
Oddometer: 207
TL 125 transmission problems?

I recently acquired a very nice TL 125 not running that has linkage attached to shift shaft and shifter not direct with pedal. I rebuilt the carb and got the bike running but it won't shift into any gear whether running or not. Shift shaft moves same amount of degrees pulling up or stepping down and I hear a clunk on the opposite side (Clutch side) but no movement in gears. I'm thinking of pulling the clutch cover and taking a look at shifting mechanism in there. Anyone had a similar problem?
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Old 11-23-2014, 06:55 AM   #2
Beastly Adventurer
Joined: Oct 2011
Location: nm
Oddometer: 2,354
Have you tried shifting while bike is rolling. Or remove the chain and spin the countershaft sprocket. Before you tear in it too far maybe try to remove the linkage and use the shifter only.
I had a brand new Fantic once , straight out of the crate. Never did find anything wrong, replaced the shift forks since the importer sent them. Bike was fine from then on. The forks were identical except from a heat mark from trying to shift. Good luck.
Relentless hard on to remove the all day dab.
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Old 11-23-2014, 07:14 AM   #3
wardie OP
2 Wheel Power Hour
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Joined: Jun 2008
Location: Youngstown, Ohio
Oddometer: 207
Yes doesn't matter the shift shaft only moves each way so far then stops. Whatever it is I can hear it stopping inside the clutch cover. I can try putting the shift lever on direct and see if that moves it but I have my doubts.
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Old 11-23-2014, 08:28 AM   #4
Motoing for 43 years
Joined: Mar 2013
Location: Wichita Mountains SW Oklahoma
Oddometer: 1,019
My fav way to feel a tranny work is to put a bike on a stand then sit on the left side. I rock the back wheel with my right hand while shifting with my left. I don't stab at the shifter but rather hold pressure up or down, feeling the drum, detent, forks, and sliding dogs as they move. I also watch the shifter move to see if there are any differences in how the gears slide and engage dogs relative to the degree of sweep on the shifter. Problems like a bent shift fork will cause a late engagement on a shift up or down, and cause the gear to pop out when loaded or unloaded. Problem with the

Rotary drum transmissions are pretty durable, but they can be damaged by stomp shifting or by crash impacts. I have found most of the delicate bits to be outside the center cases, specifically the shift selector, which can get bent or break. Sometimes the problem is simply the a shift selector biasing spring that is broken or popped off so the selector won't engage the shift drum pins. The shifter will move each way to a stop, but not rotate the drum.

Here's an animation about rotary drum sequential-shift transmissions. Ignore the dual-clutch part. The vid shows how the gears work by sliding sideways and engaging-disengaging. The rotating drum and shift selector are missing in the animation.
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