Barrel Kits

Motorcycle Barrels

Kits are great for increasing your power or capacity, but the Vespa/Lambretta engine has been left far behind in relation to motorcycle barrels.

Motorcycles have been using two stroke engines for ages and the engines have advanced slowly but surely each year. By the mid 80s most production two stroke street and off-road bikes and ATVs were water cooled, had reed valve intakes, and were starting to venture into ignition timing and exhaust valve technology. These changes are beyond the limits of most scooter barrels, and suddenly allowed a huge amount of power to be created. 250cc bikes were starting to creep into the 40 horsepower range, 200s were into the 30s and the 125cc bikes were anywhere from 15-30 hp. Below is a list of two stroke cylinders that may be good candidates to engineer on to a scooter. I have yet to see a working cylinder based power valve on a scooter but I am working on a Lambretta cased Kawasaki combo that I will update as the project progresses. The existing stroke of the scooter you are trying to convert is typically a good start for a conversion. These are typical crankshaft strokes for Italian scooters:

  • 51mm Small frame Vespa
  • 57mm Large frame Vespa
  • 58mm Lambretta
  • 60mm Long stroke Vespa

Any crankshaft that is successfuly matched to a motorcycle barrel will have to be very strong and should have the con rod replaced so I have only listed the biggest capacity scooter cranks and ones that tougher full circle cranks (or even welded crank pins) are available or adaptable for. Wherever possible I have added links to pages & visuals on the cylinder and a history of cylinder changes throughout the model run. Most bikes were sadly not available in the USA but cyclinders are sometimes available. I hope this helps to create some fast scooters!

 

Make
Model
Bore
Stroke
Exhaust Valve
HP
Yamaha
Yamaha
YZ125
54mm
54.5mm
Yes
no spec
82-83 Yamaha
RD125LC
56mm
50mm
Yes
17 @ 9000
Yamaha
TZR125
mm
Yes (YPVS)
02 Yamaha
TZ125
54mm
54.5mm
44 @ 12,250
Yamaha
DT200
66.8mm
57mm
Yes (YPVS)
31 @ 8500
Yamaha
YZ250
66.4mm
72mm
Yes
82-83 Yamaha
RD250LC
54mm
54mm
No
36 @ 8,500*
88-90 Yamaha
56.4mm
50mm
Yes
50 @ 10,000*
87-90 Yamaha
56.4mm
50mm
Yes
50 @ 10,000*
02 Yamaha
TZ250*
56.4mm
50.7mm
Yes
89 @ 12,250*
80-83 Yamaha
RD350LC
64mm
54mm
No
47 @ 8,500*
82-90 Yamaha
64mm
54mm
Yes (YPVS)
59-63 @ 9,000*
Yamaha
64mm
54mm
No
84-87 Yamaha
RD500LC*
56.4mm
50mm
Yes
85 @ 9500*
Honda
Honda
54mm
54.5mm
Honda
NS400*
57mm
50.6mm
72 @ 9500*
97-01 Honda
NSR125
54mm
54.5mm
15 @ 9500
Honda
MTX200
67mm
55mm
27 @ 7500
86-89 Honda
TRX250R
66mm
72mm
81-84 Honda
ATC250R
70mm
64.4mm
85 on Honda
ATC250R
66mm
72mm
pre 84 Honda CR250 66.4mm 72mm No
84-85 Honda
66.4mm
72mm
Varied per year
86 on Honda
66.4mm
72mm
Yes (ATAC)
Honda
Kawasaki
Kawasaki
KX125
Yes
81-92 Kawasaki
KR-1*
54.5mm
54mm
Yes
60 @ 11,000*
Kawasaki
66mm
58mm
Yes (KIPS)
Kawasaki
KDX220
69mm
58mm
Yes (KIPS)
37 @ 7500
Kawasaki
KX250
66.4mm
72mm
Yes
85 Kawasaki KXT250 70mm 64.9mm No
86 Kawasaki KXT250 70mm 64.9mm Yes
Suzuki
Suzuki
RM125
Suzuki
RG125
56mm
50.6mm
33 @ 11,250
89-97 Suzuki
RGV250*
56mm
50.6mm
65 @ 11,250*
Suzuki
RM250
85-88 Suzuki
RG250*
54mm
54mm
45 @ 8500*
85-86 Suzuki LT250R (ATV) 67mm 70mm No
87-92 Suzuki LT250R (ATV) 67mm 70mm Yes (SAEC)
85-89 Suzuki
RG500*
56mm
50.6mm
Yes
95 @ 9500*
Aprilia
Aprilia
Tuono125
54mm
54.5mm
Aprilia
RS250*
56mm
50.6mm
Yes
87-91Aprilia AF1 125 54mm 54.5mm 27 @ 8,800
84-02 Aprilia RX125 54mm 54mm 34 @ 10,750
Aprilia RS250* 56mm 50.6mm Yes
86 Aprilia 250 Tuareg 72mm 61mm 47 @ 8000
84-87 Aprilia RX250 72mm 61mm 47 @ 8000
Cagiva
Cagiva
Mito125
56mm
50.6mm
Yes
27 @ 10,500
Cagiva
Raptor125
56mm
50.6mm
KTM
KTM 125 54.25mm 54mm
KTM
SX125
54.25mm
54mm
KTM
EXC125
54.25mm
54mm
KTM
EXC200
64mm
60mm
46 @ 8700
KTM
SX200
64mm
60mm
KTM
MXC200
64mm
60mm
KTM
SX250
67.5mm
69.5mm

* notes twin or multiple cylinder bikes, but each cylinder is independently cast.