Modern Vespa

I have a fly wheel on a VBB that is ever so lightly touching the engine case on each revolution. The crank is new and true. Is this something I should address with a file or what else do you think? It happens in one spot and it is very slight but you can hear it when you turn the fly wheel by hand.

Try beating the flywheel cover with a soft mallet and just expand that one area. If that doesnt work you could buy an aluminum spacer or throw a washer underneath.

I don't think that's what he's talking about.

Oh whoops. Re-read that.

Hmm. Is it touching up near the top? I've seen inside of a flywheel rub against the cases. Is that what you're dealing with?

I'd be thinking about checking if the bearings are seated properly and making sure it's not making the crank rotate off centre... I had that on my first engine and it mashed the rotary pad...

You could see the crankshaft stump on the flywheel side, spin in an oval pattern of that makes sense...

I had a situation on the VNB where the crank wasn't pulled in all the way. Cases still closed, flywheel seemed ok until you torqued the fly wheel retaining nut, then you'd get some grinding.

Solved by putting the crank puller back on and drawing the crank into the clutchside [Flyside] ]maybe an extra mm? It was miniscule, but it solved the issue.

YMMV, etc, etc

So pull the clutch cover and clutch and then reuse the crank puller? Makes sense, but sucks.

I think that will make it worse. You need to pull crank towards the flywheel side to move flywheel out.

ABSOLUTELY!!!

Mistyped/brainfart/etc

Flyside not clutchside!

I was thinking about taking my electric impact wrench to the flywheel but, under the theory this would pull the crank and fully seat it.

Sound crazy?

Yes, that's a little crazy because would only tighten the flywheel more on the crank taper, wouldn't move the crank. There is a proper crank pulling tool, but you may be able to do something like this, on the flywheel side. I use a big washer under the tube to spread the load. The cover w/ a hole in it is to pull in the clutch side. I don't want to risk using the crank treads to pull it, so I welded this up.

Thanks - I have a proper SIP crank tool...trying to figure out a method for the fly side...I've only pulled cranks from the clutch side.

I'd remove the stator and hang it to the side then heat the case with a hair dryer or something before you pull on the crank.

Why not buy the correct tool to do all this? a case seperator tool will not only seperate your case, but it will move your crankshaft from either side. I have the original tool in my shop, but an economy version exists and is available for purchase. appears Scootermercato is out, but there is also this:
https://www.sip-scootershop.com/en/product/demounting-tool-sip-crankshaft-clutch-side_38886000