I’ve got a leaking base gasket on the R/H cylinder of my V50ii. Not a major leak but I’d like to sort it.
I know what I’m doing with an overhead camshaft engine but this is the first pushrod engine I’ve had. I’m assuming that it’s a much more simple job as there’s no camchain or cam timing to sort. Is it a pretty simple job to pull a head and barrel off? Is there anything I should be aware of?
A small block expert will be along, I do not doubt.
At the risk of being facetious, when you reassemble do not use a pencil to check tdc. Search “pencil” in 
to see why!
I will not be using my combustion chamber as a pencil holder. I’ve also read a similar story in a Suzuki forum so I guess it’s not all that uncommon an accident. I’ve also read a case where someone used a screw driver and got it jammed in there. When they disassembled the engine, there was a nasty gouge in the piston.
Yes, it is a simple job. Can’t think of any nasties awaiting you at all. You’re about to come face to face with your first Heron head 
RTM first - either Haynes or OEM.
Excellent. I have both manuals so should be good.
Hi Steve
Your leak might be emanating from the base gasket but it’s just as likely to be one or both of the 2 o-rings that seal the pushrod tubes (9070 6252) or the red silicone o-ring (6102 7200) for the cylinder base oilway, all of which tend to crumble or squash flat with age. Pick up a set from Gutsibits at a quid each before you start the teardown, to save frustration later: for the cost it’s absolutely worth your while replacing them while you’re down there.
Whipping the head and barrel off is a doddle; getting the barrel back on again less so, mainly because the long spigot at the bottom of the cylinder makes using a conventional piston ring compressor just about impossible due to the lack of clearance, so you will have to improvise!
I’d love to know how others do this – please post your suggestions! I ended up removing the piston leaving one circlip in place; inserting the piston into the base of the the barrel on the bench using the compressor and leaving the skirt peeping out; then lowering the barrel plus piston onto the carefully positioned small end (some device for holding it in place will have to be manufactured), pressing the pin through (with about 5mm clearance top and bottom), then wrangling the second circlip into place. It took me several hours and more than a week’s allowance of swear words.
You will want to use at least one new circlip (assuming you kept one in place) and on that topic, your V50ii has a 15mm gudgeon pin, for which circlips seem somewhat hard to find. At Gutsibits they seem to be constantly on backorder. Stein-Dinse say they have them, but on both occasions I ordered they sent me clips for the 18mm pin used on the Mk3, under two different part numbers! I have since put the lovely Lisa Gröper to rights on this.
Despair not: circlips are available, as so often from an unlikely source. It turns out that Vespa is your saviour Pair Vespa Piston Circlips 15MM X 1.2MM G Shaped For Malossi 133/139/166/ DR177 - VespaJets Online Vespa Parts and cheap as chips too.
Good luck with the rebuild. The V50 is a fabulous and underrated machine, and we need to keep as many as possible on the road, hopefully forever!
Best
Piers
Thanks Piers. Thats a lot of useful info. Ill get those o-rings, it’ll be worth replacing them while im in there. For what it’ll cost, it would be daft ot to.
This forum at its absolute best. Chapeau!
Merci mon vieux!
Two screwdrivers and a forehead 
I used to hold the rings in the groove with two small flathead screwdrivers and then push the barrel down with my forehead.
Needs must 
You’e a brave man Dai. I tried that, and snapped the oil scraper!
P.S. I take it you were wearing a lid when you head butted the barrel?
The V50 is a fabulous and underrated machine
It certainly is. Ive ridden a few classics worth three or four times as much which were nowhere near as good to ride. A bargain classic for those who appreciate them.
Nope Puts a big smile on your forehead though.
To refit the barrels, I use big Jubilee clips to compress the rings. Do them tight enough to hold the rings in but not so tight that they don’t slide down the piston.
Ian