124″ Upgrade to 120R Kit
This is the newest kit offered by T-Man Performance. This kit allows you to make your 120R a 124R without any case modifications. We paid special attention to our piston weight so that our customers would not have the expense of having to rebalance their flywheels. We then install oversized intake and exhaust seats. This process allows the intake and exhaust ports to work with our custom made 2.130 intake and 1.680 exhaust valves, with corrected geometry built in. Both intake and exhaust ports are hand finished, then machined with our multi-angled cutters to insure a smooth flow rate. This kit is includes our custom 4.125 piston set, gaskets, and a T-Man cam of your choice to fit your riding style.
This is the perfect upgrade for your 120” R motor.
Click the Kit Details tab for a complete description of parts and labor as well as pricing for options described above. For more details on the best fit for your riding style – call T-Man Performance.
Kit packages require your cylinders and heads be sent to T-Man Performance for work to be completed.
* When not using T-Man Performance pistons the builder is responsible for checking all valve to piston clearances.
** If during the welding process, heads crack then T-Man Performance is not responsible for replacement and up-charges to repair.
|Valve Sizes||2.120″||1.700″||-.003 / 102cc|
|Valve Spring Installed Height||1.860″||1.860″||-.020 / 98.5cc|
|Valve Spring Seat Pressure||185lbs||185lbs|
|Valve Spring Pressure @.600″ Lift||420lbs||420lbs||-.040 / 94.5cc|
|Valve Spring Travel||.770″||.770″|
|Valve Seal/Top Retainer Clearance||.760″||.725″||-.060 / 91cc|
|Compression Release Options||Auto (OEM)||Manual|