Second gear issue?

[Dads_FJ]

A recent thread got me thinking of the 2nd gear issue, and I didn't want to hijack that thread.  While I've had two 1984 1100's and both of them having the 2nd gear slipping out - others claim they have had zero issues at all on earlier models.

This is a place to get to the bottom of how bad the problem is/was. 

If you've had issues with 2nd gear click the year of your bike(s) or no issue at all.  You can vote multiple times if you have multiple bikes.  Poles close 20 days from now.

Thanks

[TexasDave]

Talking to Sky Five about his 84 he stated he did not have any second gear issues but did have his gears undercut just in case when he rebuilt his motor. My personal 84 was ridden by Randy while at his shop and he found no 2nd gear issues. I think second gear problems stem from bent shift forks on bikes ridden by younger riders thrashing the crap out of them. I did vote.

Dave

[fj1289]

My 89 developed a second gear issue.   It took about 50 drag strip runs to make it happen.   It was so bad that when I sent the transmission off to be undercut that first gear was on the way out too. 

I don't consider this a "Yamaha" problem - I can't believe how much it abuse it took at the hands of a newby drag racer.   

[Sparky84]

August 84 model, Not Sure what to put.

Yes I have experienced it when it jumps out of 2nd to Neutral when hard on it and usually straight after you have changed into 2nd and pinned it but I've always related that to not shifting into 2nd properly, My Fault,   If that makes sense.

Never had it jump out whilst shifting down into 2nd then pinning it.

Until I joined this Forum I always thought there was a problem with the the tappets, but now I Know, everyone's are always noisy but that's the way it is.

So Undecided

[Charlie-brm]

Mine (1984 1100) does it a lot if I'm accelerating hard up a grade. What it does is hammer on and off, quickly and repeatedly until I back off the throttle or better, change out of 2nd gear.

I had a 1979 XS750 triple and that second gear would pop out of engagement and stay that way until you moved the shift lever up to re-engage. Totally different experience. And it was very simple to access the cogs from the side case for a cleanup on the bench with a Dremel grinding bit. The FJ is a whole different animal in that respect and so I'm just "riding around the problem."

[balky1]

Mine (1984 1100) does it a lot if I'm accelerating hard up a grade. What it does is hammer on and off, quickly and repeatedly until I back off the throttle or better, change out of 2nd gear.

I had a 1979 XS750 triple and that second gear would pop out of engagement and stay that way until you moved the shift lever up to re-engage. Totally different experience. And it was very simple to access the cogs from the side case for a cleanup on the bench with a Dremel grinding bit. The FJ is a whole different animal in that respect and so I'm just "riding around the problem."

Are you sure the gears are the prob? It doesn't sound so.... But if it is only in second....hm.... My experience with manual transmissions on cars and motorcycles is that if it pops out - it pops out. No 'on and off'.

[Urban_Legend]

I I've just swapped out my motor in my 84 FJ for an 89 1200, because of the second gear issue. It would pop out and back in with just spirited riding around town. It was like hitting g a bump and having the rear wheel pop in the air. And before anyone says that I was pushing it hard. It would happen at half throttle at about 5000rpm. Obviously it was a lot worse in the tight twisty stuff.
I had installed one of Randy's Detent kits, which helped for a while and installed new clutch plates.
I am told that from about the 88 FJ on, Yamaha had corrected the main culprit (the shift yokes) with re engineered item, the same as in the XJR1300.

Mark

[FJ_Hooligan]

Mine (1984 1100) does it a lot if I'm accelerating hard up a grade. What it does is hammer on and off, quickly and repeatedly until I back off the throttle or better, change out of 2nd gear.

Are you sure the gears are the prob? It doesn't sound so.... But if it is only in second....hm.... My experience with manual transmissions on cars and motorcycles is that if it pops out - it pops out. No 'on and off'.

Charlie's description is the classic description of the second gear problem.  The engagement tabs and mating windows get slightly rounded off (due to wear from improper engagement and weak shifts).

Then instead of pulling the two gears together, like they would when properly undercut, they actually push the two gears apart under load.  This causes the two gears to separate and disengage thus reducing the load momentarily which allows the gears to come back together.  If you keep the load on, this cycle repeats causing the engagement/disengagement studder that Charlie described.

[balky1]

Mine (1984 1100) does it a lot if I'm accelerating hard up a grade. What it does is hammer on and off, quickly and repeatedly until I back off the throttle or better, change out of 2nd gear.

Are you sure the gears are the prob? It doesn't sound so.... But if it is only in second....hm.... My experience with manual transmissions on cars and motorcycles is that if it pops out - it pops out. No 'on and off'.

Charlie's description is the classic description of the second gear problem.  The engagement tabs and mating windows get slightly rounded off (due to wear from improper engagement and weak shifts).

Then instead of pulling the two gears together, like they would when properly undercut, they actually push the two gears apart under load.  This causes the two gears to separate and disengage thus reducing the load momentarily which allows the gears to come back together.  If you keep the load on, this cycle repeats causing the engagement/disengagement studder that Charlie described.

Aaaaahhh, thanks for the description! 

[Charlie-brm]

You summed it up nicely. What you are calling tabs and mating windows . . . is that the same as what I call the "dogs" on the sides of the gears? In the case of my XS750, I took two gears to the bench and ground the engaging ends of the rounded off detents back to a near vertical profile. Rode it for a few years after that, forgetting I ever had the problem to begin with. Nothing with shift forks was involved.
But I realize with the FJ the guts have to be opened up so the shift forks would need to be inspected/replaced too while I'm in there.

Mine (1984 1100) does it a lot if I'm accelerating hard up a grade. What it does is hammer on and off, quickly and repeatedly until I back off the throttle or better, change out of 2nd gear.

Are you sure the gears are the prob? It doesn't sound so.... But if it is only in second....hm.... My experience with manual transmissions on cars and motorcycles is that if it pops out - it pops out. No 'on and off'.

Charlie's description is the classic description of the second gear problem.  The engagement tabs and mating windows get slightly rounded off (due to wear from improper engagement and weak shifts).

Then instead of pulling the two gears together, like they would when properly undercut, they actually push the two gears apart under load.  This causes the two gears to separate and disengage thus reducing the load momentarily which allows the gears to come back together.  If you keep the load on, this cycle repeats causing the engagement/disengagement studder that Charlie described.

[FJ_Hooligan]

Yes, the tabs/dogs mesh with windows in the mating gear.  Undercutting/beveling/angling the sides of the dogs and the sides of the windows helps pull the gears together under load and keep the gears meshed.

If it happens enough, the force pushing the gears apart will deform the shift fork allowing the chattering to happen more often and under lesser loads.

I has a '78 XS750 triple that also did something similar.  If I launched hard from a stop in first gear then rolled off the throttle (like when trying to do a snap wheelie) when I got back into the throttle, the transmission would jump into neutral.  Right as I would give it a fistful of throttle, the neutral light would come on and the tach would peg!  YIKES!  It only took a few instances until I learned not to do that.  :-)