Neutral Switch Cam

[Rocketsled]

The Benly was partially disassembled when I bought it.

I thought the transmission was, in some way, busted.

Turns out the PO had disassembled the neutral switch cam and misplaced it, allowing the gear select drum to move in and out, which was enough to cause it to act wonky.

Naturally, a replacement is available from Thailand for $14, and I' have the chops to replace it with a spacer that would disable Neutral detection...I'm wondering if y'all had any other ideas?

[Spokes]

I looked through my spare parts before answering your question. Regrets on not having an extra.

But I do have one loose for my current project and took some measurements that may help make a spacer until you get a replacement.

The lobe is .352" or 8.94mm thick
The lobe is .785" or 19.95mm at its highest point.

The neutral lobe is flat has metal on both sides. Yes there is an index pin, but you should not need a pin if your just making a spacer.

[Rocketsled]

Thanks, I'll make a delrin plug that's 9mm thick and about 15mm in diameter, no need to stress the rest of the switch while looking for the part.

[Spokes]

Also, make sure the index bolt & roller is installed. You don't need the neutral switch lobe to keep the shifting drum in place.

You will find the index bolt on the top right hand side of the engine case near the carb cover mount. It is a 14mm bolt.

If you remove it you will find a small roller on the bolts tapered end, or resting in the shifting drum.

[Rocketsled]

Originally Posted by Spokes

Also, make sure the index bolt & roller is installed. You don't need the neutral switch lobe to keep the shifting drum in place.

You will find the index bolt on the top right hand side of the engine case near the carb cover mount. It is a 14mm bolt.

If you remove it you will find a small roller on the bolts tapered end, or resting in the shifting drum.

You've be surprised, I think you DO need the neutral switch lobe...without it, and with the index bolt resting on the detent, part way through the rotation of the drum, it'll walk without something to resist it.

[Spokes]

Not to argue a point, but, I have a CA95 engine completely dis-assembled and pristine clean. Looking at shift drum mounted in the case, with the index bolt & roller in place and the lobe removed, the drum does not drift.

When the shifting forks are in place the drum is further locked in.

Just an observation from the bench.

[Rocketsled]

Then there may be something wrong with my shift drum, as you rotate it, there's a VERY pronounced lateral movement.

[Rocketsled]

Course, early this morning, I'm staring at the exploded diagram of the C95 and see that the Shift Drum Guide Screw ALSO has a Shift Drum Guide Collar that my motor doesn't seem to have:


collar by Matey-O, on Flickr

There are three ca95 motors at the wrecking yard and this part is going on my list for the next expidition!

[Spokes]

I happen to have an extra guide screw & collar in my stash. PM with an adress and I will send it to you.

[Rocketsled]

Cool, but hold off. I need a half dozen little pieces from the yard (Clutch adjustment screw, drain plug, the aforementioned neutral cam, misc bolts and nuts)

I'll PM you if my efforts fail.