Non-Monster, but simple/general gearbox ?

[the_Journeyman]

So... Found a Seca II 600 for $200. Everything works but it slips out of 2nd gear. What are the common causes? Shift forks? Drum?

Thanks!

JM

[ducpainter]

From my experience it is always caused by engagement dogs on the gears not staying engaged

It can be because of wear or incomplete engagement.

Once they start popping out it usually damages a shift fork.

[the_Journeyman]

Thanks!  Either way, sounds like the gearbox will have to come out.  Not a bad job for a $200 bike I suppose ~

JM

[erkishhorde]

mmmmm, Seca II. That was my first bike!  Little on the heavy side but pretty stable for commuting.

[Speeddog]

Son of a friend of mine had one, 70k miles on the clock... they're pretty durable.
Kinda uninspiring ride, but sometimes that's not important. 

[clubhousemotorsports]

You might be able to get the dogs re-cut if they are not too far gone. there are race shops out there that do this to bikes because some gearboxes are marginal at best when new. Have someone screw up enough shifts that the dogs get worn and thats the end.

option two is to find a used motor and swap them out.

[ducpainter]

You might be able to get the dogs re-cut if they are not too far gone. there are race shops out there that do this to bikes because some gearboxes are marginal at best when new. Have someone screw up enough shifts that the dogs get worn and thats the end.

option two is to find a used motor and swap them out.

We used to do that on every Yami transmission we had apart in the 70s