NEW HEAD FOR THOR 303 AND FOR THOR 303 DS

The production of the latest THOR 303 engines has been renewed thanks to the new head with lower compression ratio and a new conical needle with optimized profile.

The new head has been designed to offer more safety and to prevent possible phenomena of self-ignition due to fuels with values slightly lower than 91US “Americans”.

Thanks to the less compression, there are enormous benefits even during the start-up phase making both the manual and electric ignition action easier. The mechanical life of the flash starter and the electric starter is considerably extended.

The new conical needle, thanks to its optimized profile makes the carburetion even more smooth and stable especially in the transitional stages.

The R&D Polini TEAM has been able to keep performance unchanged and to improve the delivery of engine torque at every rpm, despite the decrease of the compression ratio.

The upgrade with the new head will be installed on the new THOR 303 and THOR 303 DS models and it will be available to all customers who already own the Thor 303. The upgrade kit includes all the necessary parts and the manual to assemble it.

Remember that even if the new head significantly increases safety even with the use of fuels lower than 91US “Americans”, the recommendation to use  AV-GAS 100LL still persists.

This fuel in addition to 100 octanes is completely free of ethanol, giving enormous benefits to all mechanical parts, to the rubber sleeves and prolong the operating life of the engine.

Code: 928.004.014 THOR 303 SINGLE SPARK HEAD MODIFICATION KIT

Public price Euros 105,00 + VAT

Code: 928.004.015THOR 303 DOUBLE SPARK HEAD MODIFICATION KIT

Public price Euros 110,00 + VAT

100% Made in Italy