RXS100 (RX100, RX135) Gear Changing Problems (With a video to explain)

[Antony]

Hello everyone!

I have an RXS100 with a weird problem. To start with, it's a barn find and it's not been used for 20 years.

When I got it, I threw it together to see if the engine was knackered. It wasn't. In this time, I noticed problems getting it into gear, clutch problems, oil leaking, scratches, missing parts, etc - but it did run. So then, late last winter, I stripped it right down again for a respray, new seals, etc, etc.

I've come to put it back together. I've resprayed parts, bought new ones, etc.

However, something which I've not been able to fix is the gear problem.

When I stripped the engine down, I also stripped the gears down to see if anything was wrong. The gears looked new and there are no missing parts (according to the manual). As far as I'm aware, it's been put back in properly too.

The problem is that:

1.  Gear changing is clunky - sometimes, it just can't change gear because something isnt aligned inside. Sometimes, as I turn the power shaft, it can sort itself out, but sometimes not.
2. The neutral switch/bearing doesn't match/line up with the drum top dowels and the sprung circular runner thing. In other words, the neutral switch will activate when not in neutral, and go off when it is in neutral - which is weird!
3. There is a groove in the drum, and a ball on the end of a spring, within a bolt. When this ball is pushed into the groove by the spring, it locks the gear drum up! What on earth?

Can any of you experts shed some light on this odd situation?

OH, here's a video demonstarting the problem: 

 

Thanks, Antony!

Edited July 10, 2023 by Antony
Poor title

[Snakebite68]

Ok, as I often say: I'm NOT a mechanic..! So take this with a pinch of salt.

 

Do the cogs come off the shafts? Is it possible that the cogs have been put on back to front? Would that make a difference? I'm figuring it could put some of them half a tooth off if you know what I mean.
The fact that it doesn't instantly drop in when you 'change gears' doesn't worry me in the slightest. When you ride, if you stop your bike in high gear and then try to go back down to 1, you have to rock forward & backwards, so that looks normal.

 

I'm sure someone else will have other ideas too.