750 Seca Won't Shift into Second Gear

So I took the bike out for a ride yesterday and everything ran fine. Started her up this morning and realized she won't shift into second gear, moving or stopped.

Shifting mechanism lever looks alright. It will move into first gear and return to a neutral position and I can also shift the bike up to neutral.

When attempting to shift into 2nd gear while either stopped or moving, the shifting mechanism feels like it runs into a wall and it won't click into gear like it will into first. What do I need to do now to diagnose the problem?

Maintainence is up to date, oil has been changed regularly, using Rotella T15w-40. This will be my first time working on the engine (and major repair) so be gentle!

 

Put it in first, and rock it back and forth (clutch out) while trying to upshift. It's possible something is just hung up.

Or, that chain guide broke (or a piece of it) and is jamming the shift drum.

 

Sounds like it'll be a chain guide if it's not something minor (like being stuck up or something).

Having only really worked on electrical problems, what is the proper way to diagnose this type of problem? I figure I can drain and check the oil for metal bits, pull the crank cover off - but what would I really be able to check at that point?

 

this lin is a instruction on guide junk removal while your in there you can look for broken springs
http://www.xjcd.org/emergency_guidectomy

to replace the guide I think calls for a splitting of the cases

crank cover ? covers the pick up coils on left side and nothing on the right side
you will need to pull the shifter cover check springs

 

Oh awesome! I had read about that, but had seen that it was hit or miss whether it worked or not. I will definitely try though.

Is it messed up that I'm almost excited at the idea of having to split the case? The idea of taking up something so monumentally new to me and so challenging almost outweighs the fact that it'll be a huge pain in the ass....oh well, old bikes are fun like that I guess!

 

You don't have to split the case to diagnose the problem. If the chain guide has broken, the repair is not hit-or-miss, but it is somewhat tedious. If you do just remove the broken peices without splitting the cases, be sure to put the final repair on your winter must-do list.
Hope that the problem is with the shifting rachet springs. Riding is much more fun than tearing an engine apart during the summer.

 

I know this is an older thread, but the same thing happened to my 1982 750 Seca the other day. Is the only access to remove the broken chain guide pieces through the shifter side, or is there access through the clutch side too? I was thinking of shining a light through one side if there is access on both sides. Thanks!

 

You will need to remove the exhaust system and drain the oil, and remove the oil sump , once out you can look up into the engine with an inspection mirror. Inspect oil sump you may find pieces of the chain guide in bottom of pan. Don't disappear to much if it is breaking up there are several threads on here about replacing .