Modern Vespa

Hello again, i wanted to get the crank ready to install in the clutch side bearing. i saw in a video that there is a special puller to pull the shaft into place. If i don't have that tool ,any of you have any tips or other readily-available tools that i can use to pull it into place? thanks
fab

A short length of M10 or 12 allthread and nut, some pipe you can cut to length, lots of washers and a clutch nut. You'll need to adjust the length of the pipe as you pull the crank in.

Ok, i think i get the picture. As you tighten the nut, it pushes down in the pipe, which in turn pulls in the crankshaft?
Fab

Yep. The pipe sits on the inner race and you tighten the nut on the crank. Then you run out of thread, shorten the pipe or take out washers.

Edit - Sorry, I just realised the allthread wasn't necessary for this... was thinking about pulling a bearing in.

Update, just wondering....how do you know when the crank is fully pulled it? Will i not be able to tighten anymore? I was using a 1/2" ratchet, 14mm socket to tighten the bolt, while pulling in the crank. Does the inner-race of the crank need to be "flush" with the inner sleeve of bearing? Should i use a torque wrench or breaker bar to tighten it more? Thanks
Fab

I tried to tighten the clutch bolt to pull in the crank as tight as i could (with 1/2" ratchet). I wasn't sure if i needed to use more force (torque wrench), but it felt like i got it till the end. Looking at it now, there is a tiny gap between crank sleeve and the inner sleeve of main bearing. Is this normal?
Also, looking at the crankshaft spin, there is a tiny sliver (a few mm) distance between the crank itself and housing. I fear that if the crank gets pushed in any more, it might rub inside the housing.
As well, i turned the engine on its side (with flywheel side of crank sticking up). I tried to hammer down on the end of the shaft pretty hard, but the shaft didn't go down farther.
Any info would be great, thanks.
Fab

Don't hammer the crank in. You will bend it. On the clutch side, the crank stub should be flush with inner race on the bearing. On the flywheel side, the inner race should have a slight gap between the bottom of the race and the crank cheek. It sounds like the crank is not seated completely in the bearing. Pics of the clutch side bearing would help. You have to draw it in more with the puller.

Orwell, thanks for the reply. I guess a pic would help. As i said, the gap on clutch side is minimum. I'm afraid to pull any more as i kinda stripped a bit of the threading (at the tip). I had some help and now fixed the threading. Is hammering from the flywheel side better? Should i torch a bit of the main bearing before pushing or pulling a bit more?

The crank isn't fully seated in the bearing. No hammering. The puller should work if it is set up correctly.

Orwell, ok i will try to pull it a but more, hopefully it won't kill the threads 🙏🤞.
Also, should i try to torch the center bearing before pulling, or just as-is?
Thanks
Fab

You need to true the crank now.

With a puller there will be a distinct stop when the crank's against the bearing. Also look down the intake. Fully seated there should be no gap on the clutch side.

Okay, will try to pull it.
As asked...will it help to heat up the shaft before pulling at this point???
Thanks
Fab

No heat on the crankshaft, it just makes it bigger.
No heat on the bearing either, I think that may cause damage. Not 100% sure of that.

Do you have a picture of the crank before you seated it? Just wondering if there is a bit of a lip that stops it going any further.

Ray is probably correct and you may have already bent it by hammering. They are far more delicate than they look. It can usually be fixed, but please don't hammer the crank any more!

Ginch, looking at it before i installed it...yes there is a lip (stop) on the shaft...so if i pull it in the bearing, it will stop at a point.
I guess i won't torch it.
Thanks

Ok well it may have reached its limit then.

As Ray also mentioned, look in the intake. While turning the crank to open and close the valve, check that you have a reasonable seal area on the clutch side - ie it overlaps by at least 1 or 2mm.

Ginch, took some pics of the crank, as you can see, there is no overlap between Between crank seal and case. When turning the crank. It looks like it miiiight touch the case, but there is a touch of room left (red circle in picture).

You need to look into the carb inlet. Sorry I wasn't more specific.

Ginch...i'm sorry, i'm a little confused now. Where exactly should i be looking? I haven't closed the cases yet. Do i check carb inlet with piston on? If you have a pic of area to check i can take a look. Thanks
Fab

The hole in the top of the case that the carb box goes on top of. With a photo looking straight down the hole.

Orwell...my engine doesn't have the intake port on the top. The 180ss has the intake on the cylinder, not on the top of engine case.
Like i mentioned, when i pulled it from clutch side, i tightened it pretty hard(couldn't go any more) with the 1/2" ratchet. I didn't use a torque wrench. When i went a second time to tighten it, that's when the threads got screwed up at the end of the shaft (clutch side). Tried hammering hard (from the other side), and didn't move any more. I don't mind trying again to pull from clutch side, just don't wanna mess up the threads.
I think the other way of knowing if it's fully in place, will be when i close the engine with other half of the case?
Fab

Bang the crank back out with a mallet and check it's still straight first. You're going to be really sad if you run it bent.

For next time. The crank looks to be in ok. Once the clutch is torqued on the crank will fully seat, if it isn't already.

Gotcha. Get the crank out and measure for runout or have a motorcycle or machine shop do it. They should be able to straighten it too, if required. When you reinstall it, measure some reference points so you know when it's seated. We were all new to this at one time.

^^
It's almost certainly out of true now.

I would like to learn crank truing as well as rebuilding. It seems the big obstacle to rebuilding is a press. I doubt it would require anything huge. Especially if a crank is expensive or hard to find.

the trueing isn't so bad, I did it on my PX engine, which had twisted and was way out. it's running along happily these days.

The crank is turning fine, no wobble or bending.

On another odd thing...
After fixing the threads on the clutch-side, i had picked up a regular nut from the hardware store. It was the right size nut/thread pitch and goes on smoothly on the threads no problemo. I went to another hardware store (good selection of metric nuts/bolts), and got a flange nut with the right specs. When i went to put it on, it made about 1 turn on the threads then got hard to turn. Am I missing something here? Don't know why it would be tough??
I'm afraid to turn it more...don't wanna mess up the threads.
If i'm stuck, coukd i use the regular nut with a washer, or do i need a flange nut?

probably wrong thread pitch on your flange nut

Strange, will have to re-measure.

It's maybe fine vs coarse thread, you got it right on the non-flanged one.

Any wobble would show up more clearly when the case halves are put together - including the flywheel side bearing.

Must have been a different pitch on the second nut.

Not 100% sure about the SS, but around that time the standard was a washer and castle nut. Castle nut is a pita, stick with a plain nut. And the P series has a wavy clutch washer you could use and torque to spec.

Ginch...it could be the pitch, you guys are right. When looking at the flange nut vs the regular nut, the pitch on the regular one looks more course.

In this video i've been following, before putting the clutch on, there is a large, kind of Domed washer plate that almost covers the inner race of the crankshaft. Then you install clutch and all there is after is the flange nut. Nothing else.
Just wondering if i should just use the regular nut if all else fails?

Comparing the old flange nut (inside threads got destroyed), vs the regular nut. Got a profile pic as well as one from above. I know the flange nut will distribute force more evenly against the clutch vs regular nut....but, maybe it might work???

Order a proper flanged nut from Mercato.
https://www.scootermercato.com/Scooter-Parts/Clutch-Misc-Parts/S-01497
Ask them for a serrated washer to go with it.

Where is the washer/spacer from when you pulled it apart? That might be the one you saw in the video. If you lost it, order one of these -
https://www.sip-scootershop.com/en/product/washer-clutch-31x17-5x1-4-mm-sip-for-vespa-160-gs-180-ss_59133000?usrc=clutch%20spacer%20washer

These motors are fairly agricultural (at least in stock form). That doesn't mean you should go on taking an agricultural approach to motor assembly. Things should be done right. You have a good investment in your hands, in my opinion is it's time to start respecting that investment by doing stuff properly. If you had bought a vehicle and found it was full of farmer bodges you probably wouldn't be happy. No offense intended by my comments, you're the current custodian of a model that is becoming rarer. Be proud of passing it on in a better condition than you found it. Find an SS180 workshop manual and follow it carefully.

Ginch... i will end up finding the proper flange nut. I have the flare washer as well.

I don't have a lot of specialty Vespa engine tools, but I have a few that make life a lot easier.

Crank puller. I made my own by welding a clutch nut to a threaded rod. I also welded a nut on a bolt that threads into it so I can pull in the driveshaft and push a bearing race onto the fly side stub. You can get it at Scooter Mercato.

https://www.scootermercato.com/Scooter-Parts/Factory-Tools/F-2306849

The other tool which was definitely worth the money was the case splitter. On P engines, the cases are easy to split, but it's great for pushing out the crank from either side of the case.

https://www.scootermercato.com/Scooter-Parts/Factory-Tools/T-38886

For bearing drifts, I used black pipe connectors that I smoothed and ground down to fit different sized bearing races. Since then, I picked up a cheap assortment of bearing and seal drivers from Harbor Freight. There is a size for every bearing.

Put the crank in the freezer 15-30 minutes to shrink it before pulling into the bearing.

Oh ya... i was trying to find torque specs for the clutch nut torque down spec? I read on another post/ bike it was around 30lb/f. Is this for the 180 ss too?
Thanks
Fab
Ps...i ended up finding a clutch bolt..yay!