Second gear slipping?

[ThompsonJP]

HI,
I have a 1974 R90/6 and recently it's started to seem to slip out of gear and rev high in one or two quick bursts. This happens only in second gear and under hard acceleration. About two years ago, I replaced the clutch and have never had any problems with it.
I'm not skilled enough to tackle transmission problems, I'm just wondering if there are some things I can check before having a shop look at the trans.
Thanks

[schrader7032]

JPT -

Strange that it slips in 2nd gear and not say 4th or 5th. In the higher gears, the driving ratio from the engine can more easily overcome a bad clutch.

That said, I'd be sure the clutch cable is adjusted properly. Tom Cutter has a procedure for adjusting the clutch on this page:

http://rubberchickenracinggarage.com/Do ... stment.pdf

[palica]

When you say slipping, do you mean the 2nd gear does not stay engaged, or do you mean the clutch slips?
In the first case, that is of course a gear box issue and it needs reconstruction. This is a known problem on GB with a high milage.
If this is the clutch which slips (rev goes up but the gear does not change), then most probably a clutch problem, very often due to oil leak on the engine shaft, or just clutch parts which need replacement.

[schrader7032]

Good catch...I missed the "slip out of gear" part. That does sound like the engagement dogs are rounded off and would need to be serviced.

One thing you could try doing to ensure a good shift into second gear. Prior to shifting put some up pressure on the foot lever and then make your shift like normal. But continue to hold pressure on the foot lever until you've let off on the clutch lever. Take it slow and steady...can't try and speed shift these transmission.

[ThompsonJP]

I'll give that a try. What's confusing - other than my limited understanding of transmissions - is that I haven't changed anything involving the transmission. I removed it earlier this year to install a new neutral switch and oil pressure gauge, but after reinstalling everything worked fine for months. And the clutch is relatively new. That's why I'm thinking the problem is probably within the transmission itself.
Thanks

[schrader7032]

Do the easy stuff like clutch cable adjustment and shifting technique. Probably should drop the transmission fluid and check the magnetic drain plug...see if there's unusual swarf on it.

[palica]

Last thing if you removed the gear box to change the neutral switch (By the way, it is not necessary, you can just lift the engine + gear box from the back, by just removing the rear stud: it will swivel and give enough clearance to change the switch. Do not push it too high not to damage the drive shaft), make sure you put the right level of oil in gear box and when you put the shifter back, make sure it is not too low and too close to the frame. If the shifter does touch the frame, it does limit the movement of internal selector and can give the problem you have.

[srankin]

What those guys say, LOL

Seriously, I had a shifting problem with my RS, turns out, the foot peg had dropped down due to my standing up at a bad rail crossing, and hitting it too hard. Don't scold me, we all make mistakes.

This put the shifter lever at odds with the frame as such, the gears were not engaged properly when shifting.

You don't say how many mile on your bike, and I won't guess on how you ride it, there could be an internal wear problem.

So, like the other say, do the simple things first. Ride it until winter then if need be send it to a good shop for repair. Cheers, St.