Scooterotica

IMG_3976 by [url=https://flic.kr/p/qjrPxo]IMG_3975 [/url]IMG_3977 [/url]IMG_3988 by [url=https://flic.kr/p/qvq5r1]IMG_3987 [/url]IMG_3982

I have just bought a after market cylinder barrel for the GS150, I knew it would not be great and my suspicions were proven correct. But I wasn't buying it for a restoration, my plans were to use the barrel and get the scooter engineers to do there magic and fit a modern manifold and carburettor straight on to the barrel, like the original GS150. I won't be going any bigger than a 24mm dellorto or similar on the carb, the piston bore is 58.7mm. I wasn't going to change anything else as its not that easy, if pushed I could install a better exhaust. Your thoughts.
Clutch 22/26 teeth
Primary Drive/Xmas Tree 12/16/20/24/67 teeth
Gear Cogs
1. 58th 11mmX118mm (approx measuremeant)
2. 54th 9mmX111mm
3. 50th 9mmX102mm
4. 46th 9mmX94mm

If I went down the Quattrini road, would that be to powerful for the rest of the engine and does anyone have a Quattrini base gasket so I can see how much would need to be removed from the original GS casings. I know it has been done before, in Italy but there is no information other than a 40second video on Youtube and the engine is on a stand.

cheers Gary

Why don't you just tune the original barrel. Lots of HP are hidden in this nice 2 port/piston ported cylinder.

fastfrog wrote:Why don't you just tune the original barrel. Lots of HP are hidden in this nice 2 port/piston ported cylinder.

It is an option, but I feel the original carburettor will not be up to it due to its age and the wear & tare of the parts. I know you can get most parts for the carburettor including slide, jets & float chamber. I also know you can get the carb body honed to take a larger slide again another option. I would just like to know if there are other options out there where I can keep the engine as original as possible and only use remade parts.

Engine Casings are more available than original barrels and carburettors.

No experience in this tune: But looking at the evidence I would follow Fasfrog's approach with an altered inlet manifold with appropriate rubber and carb of your choice (PHBL?): Reasoning = the Clutch capacity and lack of ready exhaust options.

Yanker wrote:No experience in this tune: But looking at the evidence I would follow Fasfrog's approach with an altered inlet manifold with appropriate rubber and carb of your choice (PHBL?): Reasoning = the Clutch capacity and lack of ready exhaust options.

That was my plans for the remade barrel, open that up and fit a reed valve, just not sure how much work can be done on the barrel. As for the exhaust, there is an American company who make a performance exhaust with all the correct attachments. I was also thinking that I could change the threaded section on the barrel by getting it turned to accept a standard Vespa exhaust or add the large nut to a standard exhaust and keep the threaded attachment on the barrel.

The GS clutch has a strengthened band welded to the basket, so I think that might be ok. I was more worried about the actual gear change as the selector is not the strongest part.

I am hoping the tuning shops would have a look to see what can be done to the barrel and how easy it would be to change it to a reed valve set up, similar to the Quattrini.

Be worth speaking Sean Bradey @ Scooterotica Gary... he built my quattrini motor (amongst others) and is a vespa tuning guru & an all round top bloke... and SIP sell gasket sets for the Quattrini m1xl http://www.sip-scootershop.com/en/produ ... +_15045400

GLscoot wrote:

Yanker wrote:No experience in this tune: But looking at the evidence I would follow Fasfrog's approach with an altered inlet manifold with appropriate rubber and carb of your choice (PHBL?): Reasoning = the Clutch capacity and lack of ready exhaust options.

That was my plans for the remade barrel, open that up and fit a reed valve, just not sure how much work can be done on the barrel. As for the exhaust, there is an American company who make a performance exhaust with all the correct attachments. I was also thinking that I could change the threaded section on the barrel by getting it turned to accept a standard Vespa exhaust or add the large nut to a standard exhaust and keep the threaded attachment on the barrel.

The GS clutch has a strengthened band welded to the basket, so I think that might be ok. I was more worried about the actual gear change as the selector is not the strongest part.

I am hoping the tuning shops would have a look to see what can be done to the barrel and how easy it would be to change it to a reed valve set up, similar to the Quattrini.

Right this could be very interesting to see if a Quattrini reed block (or any other one) could fit with a small amount of work on this barrel. best way to get a 2 main/2 boost port system. A rocket thereafter.....
If you need help to upgrade the barrel dont hesitate to PM me....

fastfrog, PM sent.
cheers

Nice pics you add there. May the force (of dremel) be with us.