Modern Vespa

So, the time came to mate the two halves of my stock 180SS motor together. I laid out the bolts etc. ready to put in place when it came together, attached the kickstart lever to the quadrant and gently put the right side over the left side. It slid gently down the studs that are in the LHS case then stopped!
1. I had the kickstart rotated to engage with the engagement gear.
2. The gear change barrel appeared in the appropriate hole, but didn't come out into the clear air.
I fiddled around with the kickstart hoping to free the right case but to no avail.
So, I took it apart again and took the kickstart quadrant out (oh the joy of taking that spring off) and made sure the end of the quadrant fitted the bush it is meant to go into - it does.
So, I refitted the kickstart quadrant and spring, and fitted the kickstart lever and tried again. Alas, no luck.
Am I missing something?

Here's the parts diagram for the SS180 kickstart. Maybe take a few pictures of your project, and someone can help spot the problem.

Some photos for help - possibly.

Do you have the primary shaft nut loose (or off)? If this is tight cases are difficult to get together.

You'll have to install the kickstart gear on the other side before puting the engine halves together.
When the halves are almost together you can use the kickstart lever a bit so the last few mm'ers goes easy without to much force.

Sorry for the dirty picture, this is my GS160 engine before overhaul.

Pilaf is right. The kickstart gear needs to simply rest between the engine case and the little leaf spring just like his photo. It will stay put wedged there. The other side goes on as the shaft goes through the gear and then it all snaps together nicely with a bit of wiggling the kickstart lever.

I always put the cog on the primary and move the quadrant with the kickstart while closing the cases. It drops right in...

SaFiS that's not possible with the GS/SS engine. As you can see in the posted picture, the teeth of kickstart cog is partial installed under the kickstartshaft (between the spring and kickstartshaft) and in the free space (milled part) of the engine block.

Correct. That lip the gear sits under is the difference.

The GS/SS engine has several odd things that make quite atypical to other engines.

and sometimes not unlike a smallframe.

Well team, I have just spent a couple of very hot sweaty hours in the garage, and still no success. The only improvement is that I have shellaced the gasket to the left case to avoid the frustration of it coming off the right one and threatening to tear each time I separated the cases again, and I suspect the cases are slightly closer than they were but movement is nil.
This may end up with the local dealer for him to put the cases together.
Thanks for the suggestions to date.

Hi I just noticed you are in Hamilton. Do you know the guys at NTB? They rebuilt my SS180 engine so might be able to advise/help.

Before you go to the dealer, you can check the following.
Maybe the pictures gives a wrong impression but imo the kickstart shaft is not completely in the correct position. A few more taps will do. Same with the crankshaft, looks like it's not completely centered in the crankcase and need to be pressed a little more towards the clutch bearing.
GS/SS cases are friendly when it comes to splitting the cases because of the "open" flywheel bearing. There is no hard tapping or force necessary both in dissembling as assembling.

^^^
Good eye.

I spent an hour with them at lunchtime today, and know them well. I talked about my difficulties and they offered some other thoughts as well, but the suggestions above warrant the first try.

Thanks, a good start for another effort over the weekend.

I actually spoke to the dealer and he also suggested taking the primary set of gears out, and possibly the secondary, and trying with just the crankshaft and kickstart in place, including leaving out the engagement gear. I will try your suggestions first though.

For the crank you can use some cheap and simple hardware to pull the crank without damaging the clutch bearing. When you use this method it is easy to feel when the crank is seated and you can see and measure when/if the crank is perfect centered. The photos shows a GS160 crank but it is the same method and hardware for the SS crank.
Good luck with your weekend project

I have never rebuilt a Vespa engine but from builds of other engines I am in the habit of trying individual parts with the case halves bolted together....like crank by itself, cam by itself, crank with camshaft. Doesn't apply to Vespa exactly but you get the idea. It helps to isolate which part is not moving freely.

I think you are probably not far off.