Modern Vespa

Hi All,

I sourced a SS 180 engine for my scoot and in the process of doing a rebuild. I'm finding it hard to remove the cylinder from the engine. I took off three of the cylinder studs off, piston travels freely in the bore, but can't manage to slide out the cylinder.

I'm thinking someone used super sealant on the base and it's superglued on the engine. Any thought on how to free it?

Mandatory pics of the engine:

Heat the joint with a propane torch? Might soften things up.

^^ 2nded

heat and tap around the barrel with a mallet, a soft face or even a small block of wood. and seriously just *tap* it around. all you're trying to do is introduce a little wiggle and then you should be able to work it around and get it off.

I've done this before, and I don't recommend it... but, if the piston is in a position where is is moving past the exhaust port you can put a wood dowel in there and try rotating the motor. piston contacts the dowel, jams it agains the exhaust, the movement of the piston pushes the barrel up and off.

but really, I'd just heat it and tap it till I got it.

worst case you could always crack the cases and pull out the crank and barrel/piston together.

First... Congrats on scoring an engine!

Second... All the above. Heat and some tappy slappy and you should be gold.

Thanks for the advice! I'll try some heat and will let you know how it goes

I assume you are planing on opening up the cases anyway...... no?

Oh yes, working my way to opening the cases to change seals, bearings, etc.

Happy to report that some heat and gentle tapping with a rubber mallet did the trick. Woo hoo!!!

Now for the next questions:
1. I have one cylinder stud that is being stubborn and won't turn. I am using the two nut method to remove but the nuts are turning while the stud stays still. Should I apply some heat here as well?

2. Any good tricks for removing the fudge on pin from the piston? Can't get it to budge.

Here are pics of the barrel removed.

on the stud, heat the case a little and see if it'll turn out. I generally recommend against getting ahold of the piece with some vice grips, but you may need to employ that tactic here.

the same on the piston, throw some heat at it and see if you can get it to move. a 10mm socket is usually just the right size to fit in there and give it a shove. try and avoid reefing on it for the sake of the crank/conrod.

a piston pin puller is really the right tool, but if just pushing on it doesn't work you can fake one with a 10mm socket, another deep socket, say a 17 and a length of all thread and two nuts.

Why bother to take out the stud?

G-man again with the good advice.

Aside from tons of heat on the case around the stud, I'd also smack (lightly) the cylinder stud from both ends a few times to try and loosen up the rust/grit etc. Additionally... after heating dont be afraid to try and tighten it just a hair. Wiggling the stud left and right is just fine. You are trying to introduce the slightest movement in either direction. If you get any movement keep wiggling until you can start loosening the stud by degrees.

Piston grudgon pin... allthread as Greasy said. Pic below

This is a very handy trick for struck fasteners and it allows the penetrating oil to travel into the threads. It also works beautifully for screws in wood.

Hi All,

Any opinions on this SS crank? I noticed sone pitting on the metal, just curious if this will affect it in any way and if I'm still ok to use.

Great you found a motor ! I doubt the pitting would do any more than alter the chamber volume by a miniscule amount but I'd be concerned about the seal contact surface and the condition of the con rod bearing.

Yeah, it's the pitting where the seals would sit that has me worried. The rod has a little side to side play but no up/down play so I think it should be ok

OK, this project is stop and go and have been making some progress. Tonight I was refitting the kick start gear. The gear was not sliding easily through the hole. Gave it a slight tap with a rubber mallet and found two issues:

1. I found a small crack in the case by the kick start hole. See pics below. Does it look bad enough to be concerning and is it fixable?

2. Could the kick start gear be bent ever so slightly, hence why it will not easily slide into the case?

The shaft looks bent. If you put a straight edge on it, you'll probably see a gap. Most likely the bike went down on the right side on the kickstart lever and bent the kickstart shaft which cracked the case. The cracked case can be repaired by a skilled person. Have someone who knows Vespa engines weld it and not just some welder dude. It needs to be done right. Then get a straight kickstart shaft. There should also be a rubber o-ring inside that opening about a half inch down inside a machined groove inside the case. This prevents oil from seeping out.

shaft looks sus AF, I'd be replacing that straight away.

while I don't think that the K/S lug is going to fall off, I can almost guarantee it's going to lead and the crack is going to get bigger.

it needs repaired properly, by somebody that knows what they're doing.

What is it with SS180's and KS failures?!? Gah.

I have lived and breathed similar.

100% repair the crack. Replaces the quad. Repair needs to be done by someone skilled (Gick, Casola, etc).

Good luck

Thanks for the advice everyone. New kickstart shaft on order & have a good lead on someone who can address the crack. A will keep you posted with progress.

On a good note looks like SS pistons are back in stock at SIP, so added that to the order.

Sometimes you have to back track a bit to move forward I guess