Technology Information

Pavesi ICC Evolution Engine Break-In

Start by increasing the main jet by one to two sizes from what you have
determined to be the optimal jetting, taking weather, altitude and track size
into consideration. Always warm-up the engine on the stand (in 1st gear)
and do a walk around of the engine and kart...

  •  Check for loose nuts and bolts.
  •  Check the water level and add tape to the front side of the radiator.
  •  Warm-up engine – Remove the radiator cap, to check for proper water flow.

Check to make sure that the clutch lever has ¾” to 1” of play. And, that the
clutch lever, cable and actuator arm retract properly. The clutch lever action
should have a light and free feel to it (We offer an easy-to-use cable
lubrication device, to achieve this).

Break-in water temperature should be 145 to 155 degrees, with the normal
running water temperature at around 125 degrees. You can take the temperature reading anywhere between the cylinder head outlet and the radiator.

Out on the track, run at reduced lap times of 15% to 20% below normal (On
a 30 second track, slow the pace by 4 to 5 seconds per lap.). Go through the
gears as normal, modulating the throttle and shifting at approximately
13,000 RPMs… Blip the throttle, when going into corners and / or if you are
coasting. Towards the end of the break-in, gradually increase the pace by
approximately 1 second per lap.  Keep in mind, break in is always done with a full throttle application.  To keep speeds and engine RPM's low, short shift.  Partial throttle will cause a lean condition.

Once you’re up to speed, you don’t have to
come in and let it cool down… Just run it!

  • New engine break-in – 15 to 20 laps.
  •  New top end break-in – 8 to 10 laps.


Be prepared to advise us what race series that you are participating in and what the "spec oil" is for the series. Note: For most sprint racing applications, we recommend a 24:1 mix ratio.  If the oil is open, we recommend the use of Motul Kart Grand Prix or the Maxima 927 products.

The Pavesi Evolution ICC engine has two separate compartments for the transmission oil and the gearbox oil, but you can use the same product.

For the transmission, we recommend that you use 16oz / 450ml of Motul Transoil
2-stroke gearbox oil if your engine is brand new or freshly rebuilt.  Use 50ml less, for routine oil changes (every 5 to 6 hours).

For the clutch, we recommend that you use 8oz / 225ml of Motul Transoil 2-
stroke gearbox oil if your engine is brand new or freshly rebuilt... Use 25ml
less, for routine oil changes (every 5 to 6 hours).

Note: After every 2nd or 3rd oil change, clean and inspect the entire clutch area and assembly (using brake, contact or carburetor cleaner), replacing any discs that are warped and / or below recommended tolerances.

Spark Plugs
Use any of the following NGK spark plugs...

  • NGK BR10EG
  • NGK BR10EGV (Discontinued)
  • NGK BR10EV
  • NGK R7376-10

Top End
• Pavesi piston kit - #1.029.30

Jetting – Dellorto VHSH 30 CS
Normal range of jets for a Dellorto VHSH 30 CS carburetor, when used in
conjunction with a SwedeTech blueprinted Pavesi...
120 - 145 main
B45 – B50 inner pilot
60 outer pilot
DQ266-268 nozzle
K22 needle (1st or 2nd clip position from the top)
Note: Even larger jets may be applicable for road racing.

Carbon-fiber SwedeTech Pavesi

Cooling System

Water flows from the bottom of the radiator to the center
of the water pump (into the face of the impeller). Water then flows out of
the pump to the bottom of the engine case and through the engine. Finally,
the water flows out of the cylinder head to the top of the radiator… No other
routing is correct.

Lower-End Maintenance

Pavesi Italy recommends replacement of the lower rod bearing and thrust washers (stock ICC Pavesi 125cc engine), after each 10 gallons of fuel that is run through the engine. Under optimal conditions, SwedeTech has been able to extend the life of the lower rod bearing to 10 to 12 hours or 20 to 25 gallons of fuel (SwedeTech blueprinted ICC Pavesi, using recommended oil). *

Top-End Maintenance

Pavesi Italy recommends replacement of the topend parts (stock ICC Pavesi 125cc engine), after each 10 gallons of fuel that is run through the engine. For optimum performance and reliability, SwedeTech recommends replacing the top-end (piston, ring, wristpin, upper rod bearing and circlips), every 2 to 3-hours of run time, or 5 to 8 gallons of fuel. When doing a top-end rebuild, check the squish between the piston and the cylinder head, using 0.040” solder (optimum desired squish 0.028” –

2004 Exhaust System – Stepped SwedeTech u-bend and stock 2004
Pegaso carbon fiber silencer.

2003 Exhaust System – “XXS” marked aluminum silencer with a sleeved
dual stage u-bend.

* It is important to remember that the rebuild numbers listed above are only
recommendations. And, when dealing with high performance racing engines,
there are no absolutes or guarantees.