Select your desired compression ratio from the drop down menu. All designs will work with stock base gaskets and cylinder heights and offer significant improvements over stock heads.
MEDIUM COMPRESSION: Similar compression ratio to stock. Gives much smoother power delivery at low/mid revs and a small increase to bottom/mid power. Squish clearance is much tighter than stock. Fuel economy is improved over stock. Recommended for riders who are mostly happy with the bottom/mid power of their TPI but want improved smoothness. Will work with the latest Sports Rider map.
HIGH COMPRESSION: Requires 98 RON fuel. Gives a very noticeable increase to bottom/mid power plus improved smoothness. Squish clearance is much tighter than stock. Fuel economy is improved. Recommended for riders who want more bottom/mid power from their TPI. Will work with the latest Sports Rider map. Due to the increase in compression ratio over the stock head this design may require a thermo fan to be fitted for tight/technical riding. We also suggest an 8 heat range plug with this head. Our ‘High” comp head is lower comp than many heads coming out of the USA and is better suited to our local conditions and fuels.
A note about TPI fuel maps…
We have dyno tested these head designs using the latest Sports Rider maps. All previous maps are too lean to run an aftermarket head.
This map is safely rich from 0 – 1/2 throttle, however above 1/2 throttle it leans out significantly. This is great for making high hp numbers but in the real world it leaves the engine in slightly dangerous territory when run at high rpm for extended periods. Often after a high rpm/high throttle run the bike will show signs of running hot/lean (hanging idle, engine knock, lack of power). For the majority of riders this will not cause issues if youre riding is mostly made up of single track or normal riding conditions… most riders rarely get above half throttle for extended periods on a 300! However if you do a lot of fast, wide open riding, deep sand, or fast, long hill climbs you will need to consider either fitting a JD tuner, or replacing the stock ECU with a programmable unit and making the necessary changes to richen up the fuelling above half throttle. Even if you are retaining the stock head we still suggest making these changes for fast riding to ensure reliability.
Our new TSP CNC cylinder heads are machined from solid 6061 T6 stock and offer improved performance, reliability and fuel economy. They are the best bolt on mod you can buy for your bike! Our design offers better heat dissipation than many other 2 piece designs due to the large lower section which incorporates the combustion chamber… this allows heat from combustion to disperse over a larger area than other 2 piece designs for improved heat transfer to the coolant.
These CNC machined 2 piece heads feature TSP’s proven combustion chamber designs and are a MUST HAVE mod for most current model offroad bikes. Our combustion chamber designs have been used by hundreds of happy customers and have been extensively dyno tested… the gains are consistent and include: increased power throughout the rev range (especially bottom/mid), improved fuel economy, greatly reduced risk of detonation, increased top end life in many models, and much SMOOTHER power delivery.
The unique CNC design has been 100% developed, machined and tested in-house at TSP.
These CNC heads will bolt onto your standard cylinder and are designed to work with standard base gaskets. If you are unsure of your current base gasket thickness we can advise the correct thickness to achieve the necessary cylinder height and squish clearance.
The customer takes all responsibility for ensuring that jetting is appropriate for their riding style and conditions.