Layshaft Rebuild

No normal restoration takes this long. I have made many major changes throughout the process and therefore, well you know . . .

Before I can move forward I need to rebuild the layshaft. Thanks to Derek, who helped me with his mill and expertise. I rebuilt it with him and used nut/bolts to hold it together, per Tom G.'s recommendation. Tom recommended creating a small whole in the punch nut to catch the head of the rivet. Thanks Derek for helping with that.

Today, I riveted it shut using a palm nail gun (I highly recommend buying the MINI palm nailer for additional control and better view of the area you are working on) again per Tom G.'s recommendation. It went well.

Next step is to put the engine back together, which I hope to do in spurts in early mornings and late nights after my kids are asleep.

Update for September

Quick update . . .

Life again has gotten the best of me . . . a new teaching job and a young family has me spread thin. No complaints though! As you know the clutch is 100% rebuilt. The layshaft (cush drive) is rebuilt and held together by hardware. I will remove one nut/bolt at a tie and replace with rivets. Once that is done I will put everything back together and test it again. If the problem is still there a new clutch it is.

In the meantime we have replaced our two Bajaj Chetaks, which I repaired and sold in July, with a new-to-me bone stock 1979 P200 with 82XX original miles on it.



I am quite smitten with it.

Barry Gwin's Vespa Clutch Compressor Tool

I called First Kick Scooters yesterday to see if they had a clutch compressor tool in stock. They did not, but I was told they just use a bolt with washers and nuts to compress clutches that come in their shop.

Then I called SF Scooter Centre and they had them in stock for $20. I stopped by to pick one up as opposed to risking damaging mine without the correct tool and Barry said, make your own. Don't buy this $20 one. He usually sells his Home Depot version ones for $5, but was all out. He drew up his design and sent me on my way.

It costs me $2.25 to make and I tested it in Home Depot and it worked great. Here's what I bought:
- 1/2 inch wing nut
- two 1/2 inch washes
- 1/2x3 inch carriage bolt

The idea is the taper on the carriage bolt is similar to the taper in the clutch. I made sure that my carriage bolt easily and freely turned so it would not score my taper in my clutch. So I guess in theory this is just like using washers, nuts, and a bolt, because my taper is not fitting the sleeve perfectly. I quickly compress, remove the circlip, and release the pressure in case this design puts undue pressure on the clutch since it is not pulling from the sleeve. I do know it is not in contact with the brass ring nut as it sits on the lip above it.

I hit Ace Hardware up yesterday, but they did not have large enough carriage bolts, so I used washers, nuts and a bolt and it worked fine if you're in a jam.

Homemade tool for the brass nut on the clutch

Thanks to Derek G. who transformed a deep socket on a lathe into this beautiful tool for me.
Derek said "The tool came out perfect. There is a .001 interference fit, so you have to push it onto the brass nuts, which keeps it tight. "

Lessons learned from complete clutch rebuild

Not surprisingly, I learned that Tom G. was correct about why the needle bearings were binding. This evening I disassembled the clutch 100% (yet again) and with a few taps all of the oiled needle bearings fell out. Furthermore, they all we reinstalled very easily around the circumference of the race. There was no binding.

A couple things to note:

(1) The entire clutch was rebuilt when the engine was done. VSX parts were used with the exception of new needle bearings. I did not receive the original ones back from Christopher M. after the rebuild so I can not compare the sizes, but I do know I just bought 40 new ones from Scooters O and Gene M. successfully installed them in another SS180 that had a similar problem and now there is no grinding noise from the clutch.

(2) A trick for tightening the brass ring I learned from Tom G. is "Put backing plate down on wooden surface. Screw two sheetrock or other screws in place adjacent to the "ears of the backing plate. The screws keep the backing plate from turning. then you use the tool to unscrew the ring. Use just enough force to get the ring to turn. " I took another approach and used three small headless nails and lined them through both plates and turned the top plate so each locked against the nail and there was no movement. I then tightened the brass ring and could lift the clutch assembly off the wood base. Tom's idea may be smarter as it could be less stress on the two plates. I hadn't reread Tom's note and could not get my Sheetrock screws to fit the holes the nails did.

(3) For the brass ring there is no torque guide and it is unlikely to loosen since it is a reverse thread. I kept my hand directly above the socket (less torque) and tightened it down with one jab. Then I stopped. Brass is not that hard.

(4) What I did notice is that the NOS clutch springs (I point to the NOS ones in the slide show) I just purchased are noticeably taller than the VSX ones. Furthermore, they sit in the cups much more snugly. I wonder what difference, if any, that could cause. I did not receive the original ones back so I could not compare the difference in height or width.

The only question now is if the scoring wear on the bottom of the brass ring nut is acceptable or if it suggest that the needle bearings will eventually wear through enough for the brass ring to fail or to cause binding of the heads of the bearings at low RPMs -- hence the sound between neutral and first gear. I want to know this answer ASAP. Follow-up: spoke with Tom and he said that the ring has wear, but not truly scoring. He said their is nothing wrong with the brass ring as-is.

So . . .

At this point, I guess it makes sense to reassemble the bike and test it. If it works, wonderful! If it doesn't it's not hard to replace the clutch and I will need to buy a new one.