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Vespa T5 polini 152 specs questions
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@nelluch125 avatar
Nelluch125
UTC
Hooked
1981 Vespa P200e, 1985 Vespa PX125e, 1985 T5, 1971 Sprint Veloce
Joined: UTC
Posts: 414
Location: St. Catharines, Ontario
 
Nelluch125
Hooked
@nelluch125 avatar
1981 Vespa P200e, 1985 Vespa PX125e, 1985 T5, 1971 Sprint Veloce
Joined: UTC
Posts: 414
Location: St. Catharines, Ontario
UTC quote
Hey everyone:

Just in the process of rebuilding a T5 with a polini 152 kit.

Just wondering if anyone knows of:

Piston ring gap for this cylinder?

Ignition timing?

Best spark plug to use?

Jetting with a the stock 24mm carb? I have a sito plus exhaust.

Thanking you all in advance and Happy New Year.
@mjrally avatar
MJRally
UTC
Veni, Vidi, Posti
73 Rally, 76 ET3, 80 P200, 61 Ser 2, 65 Silver Special
Joined: UTC
Posts: 5353
Location: Oceanside, CA
 
MJRally
Veni, Vidi, Posti
@mjrally avatar
73 Rally, 76 ET3, 80 P200, 61 Ser 2, 65 Silver Special
Joined: UTC
Posts: 5353
Location: Oceanside, CA
UTC quote
Piston ring gap I'd go general .25-.4mm

Ignition timing 18*

Spark plug id check the head and see if it uses a short (HS) thread plug or long (ES) plug. NGK B8*S plug for whatever the head has threads for.

Jetting per SIP for the stock 52 stroke crank, sito + exhaust, 24/24 carb and sport Polini 152 cylinder they show the tip to be 122-128 MJ.

If it ran before, put everything back the way it was and evaluate.
OP
@nelluch125 avatar
Nelluch125
UTC
Hooked
1981 Vespa P200e, 1985 Vespa PX125e, 1985 T5, 1971 Sprint Veloce
Joined: UTC
Posts: 414
Location: St. Catharines, Ontario
 
Nelluch125
Hooked
@nelluch125 avatar
1981 Vespa P200e, 1985 Vespa PX125e, 1985 T5, 1971 Sprint Veloce
Joined: UTC
Posts: 414
Location: St. Catharines, Ontario
UTC quote
Noted. Thanks MJ!
@safis avatar
SaFiS
UTC
Veni, Vidi, Posti
1979 P150X, 1983 P200E, 1987 PK125XL Elestart, 1988 T5, 1995 PX200E, 2024 GTS 300
Joined: UTC
Posts: 5171
Location: Veria, Greece
 
SaFiS
Veni, Vidi, Posti
@safis avatar
1979 P150X, 1983 P200E, 1987 PK125XL Elestart, 1988 T5, 1995 PX200E, 2024 GTS 300
Joined: UTC
Posts: 5171
Location: Veria, Greece
UTC quote
Stock T5 timing is 16°. I have kept mine there but with a Malossi kit and a better MRP head. Since you're going cast iron, 18° should be fine. Jetting wise I only changed the main to a 125 which runs fine along with a SIP XL…
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Forum -> Not-So-Modern

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