Cylinder barrel tune up

[salo]

Was told about cylinder barrel tune up for a vespa today. They said it's cheap to do and the improvement is massive, can't find any info about it, any ideas??

[RWS74]

Hi Salo,
As in increasing CCs? I've ordered this 150cc Cylinder kit.
Decided on a Piaggio 150 over aftermarket bigger kits as happy with 125 for economy and most of the performance but just want a little more torque on hills etc.

www.rondaleyscooters.co.uk/scooter/cylinder-assembly-px150

[salo]

Thanks RWS74 for the reply. The one I was told about was a lot cheaper, I THINK it involve shaving a bit off the piston and buying a spacer of some sort. When he was explaining it I was totally lost as I don't know a thing about engines. I know squish got a mention?

Not sure I've explained anything then, probably confused you.

[salo]

Actually I think he said he read it in a scooter mag and it'll give a 125 the same power as a 200??

[RWS74]

Blimey, that sounds good. Keep me posted if and when you find out more mate.

[sime66]

The subject can get very complicated very quickly, but shouldn’t have to at first.

In simplest terms, if your Transfer ports in your barrel are higher, the transfer duration will be longer because the ports are open for longer, and so the power will be at higher revs – you will go faster!! - - - For Freeeee!!!!!
The simplest way to achieve this is to insert a number of standard base gaskets on the barrel you have (no different barrel required at this first stage).
You may find that doing this increases your squish too much (this is the clearance between top of cylinder and inside of piston head). If this is too big you might then need to skim your barrel and/or head. In the first instance you wouldn’t have to worry about this for a few base gaskets.
I don’t know how many base gaskets, or what distance, you could increase by without worrying about other factors, about 1mm I believe, but that is hopefully a bit of clarification on your ‘spacer’ ‘shaving’ etc. story; there’s a quick free increase if you want it, or a bottomless pit of tuning addiction.

Pxguru was recently going through the same thing with phattanglo and bignico; have a look through recent threads for more detail.

In fact, and I say it quite often, a lot of this is well covered in old threads, which can be easily found using the forum search function.

If you really want to buy another barrel and get complicated, this has also been covered in great detail recently, and it’s exactly what I’m doing again now, here………….:

vespa.proboards.com/thread/6098/efl-gearbox-p150x-casings

[salo]

That's it exactly sime66. I'm still none the wiser even after reading your post. I'm very new to the scooter world (6mnths) . Do you know of a link where I could find out more info?

Thanks for the great reply

[ianmartin40]

the px tuning feature to DIY tune your barrel was in last month scootering magazine, pretty much as above, DR kits are not too expensive either.
back issues of scootering are available.

Ian

[pxguru]

The article in scootering is a bit of a tease and involves a lot more work than adding a few gaskets. The Scootering article mentions about dremeling out the exhaust port, then by the way, you will need to get your head skimmed now or it won't run. Then after state that standard barrels are cheap, to soften the blow if you mess it all up.

Adding a few base gaskets is like drilling an air filter or putting on an expansion. You will notice, your scooter will be faster than your mates but only just

[scooterbooter]

Never done it to a scoot but done this sort of Stuff to other bikes it does work but needs to be a tidy job. First time do it on something you don't mind blowing up.

[citydaz]

option 1 put a sports exhaust on - this may give you + 2hp (SIP2 exhaust)
option 2 put a std 150 head/piston/barrel on (with or without option 1)
option 3 put a BGM 177 kit on.