Motorcycle Repair: maxim 700x transmission, drum groove, mc repair

Question
Well im back...this time with a question about the bikes transmission. Yamaha maxim 700x 1985. It seems like the tranny is going. Everytime I start out in 1st gear it pops out of gear and into neutral. Doesn't matter if I try to hold it down with my foot there's no stopping it. So as a result I have to start out in 2nd gear. Is there any adjustments I can make, is there anything I can do, or is it shot?

Answer
Hi Lynette,

If the transmission gear "dogs" have excessive wear, a motorcycle's transmission will tend to find neutral. Transmission gears mate by dogs and cogs (slots and dowels). When edges on these dogs and cogs become worn they can easily slip apart resulting with transmission finding neutral.

See an image of worn dogs here:  
www.dansmc.com/dogs.jpg

Read more about transmission here: www.dansmc.com/gearbox.htm

(courtesy of Dan's online MC Repair Course: www.dansmc.com)



Gear Shifting Faulty:

Doesn't go into gear; shift pedal doesn't return

Clutch not disengaging
Shift fork bent or seized
Gear stuck on the shaft
Gear position lever binding
Shift return spring weak or broken
Shift return spring pin loose
Shift mechanism arm spring broken
Shift mechanism arm broken
Shift pawl broken

Jumps out of gear:

Shift fork worn
Gear groove worn
Gear dogs and/or dog holes worn
Shift drum groove worn
Gear positioning lever spring weak or broken
Shift fork pin worn
Drive shaft, output shaft, and/or gear splines worn

Overshifts:

Gear positioning lever spring weak or broken
Shift mechanism arm spring broken


Respectfully,
Mark Shively