Description
TSP Oversize Powervalve Cover – TBI 250-300
Increase low-RPM torque and low/mid-range performance on your compatible TBI 250-300 two-stroke with the TSP Oversize Powervalve Cover.
Designed and tested by TSP, this oversized powervalve cover is engineered to improve power delivery where many trail and hard enduro riders need it most—low throttle and low-to-mid RPM.
This is more than a cosmetic upgrade. The TSP Oversize Powervalve Cover is specifically designed to increase torque and provide a smoother, more tractable feel before the powervalve opens.
Compatibility
The TSP Oversize Powervalve Cover suits all compatible 250 and 300 TBI models from 2023 onwards, including:
- SX
- XC
- EXC
- XC-W
The cover works with both stock and aftermarket expansion pipes.
Key Benefits
- Increased low-RPM torque
- Improved low/mid-range power
- Stronger performance at low throttle
- Smoother and more controllable power delivery
- Designed for trail and hard enduro riding
- Effective in the approximately 3000-5000 RPM range
- Works with stock or aftermarket pipes
- TSP-developed and tested design
How the TSP Oversize Powervalve Cover Works
Two-stroke expansion chambers create pressure waves that help fill the cylinder and increase power at higher RPM. This is part of what riders experience when a two-stroke engine comes “on the pipe”.
At lower RPM, however, these pressure waves can have the opposite effect and make it more difficult for fresh fuel and air to enter the cylinder. This can reduce low- and mid-range performance.
Some two-stroke powervalve systems use a Torque Chamber to help reduce this effect.
When the powervalve is closed at lower RPM, the chamber is open to the exhaust gases. Pressure waves entering the chamber are partially dissipated, reducing their negative effect on cylinder filling.
By increasing and optimising the volume of this chamber, the TSP Oversize Powervalve Cover is designed to further reduce the negative effect of the expansion chamber at low RPM.
The result is more torque and stronger low/mid-range performance, particularly around 3000-5000 RPM and at low throttle openings.
Developed and Dyno Tested by TSP
TSP spent months dyno and track testing different designs and chamber volumes to determine the configuration that delivered a noticeable improvement in low/mid-range torque.
Dyno testing on a TSP-equipped 2024 KTM 300 EXC TBI demonstrated further gains in horsepower and torque at low RPM when the Oversize Powervalve Cover was added to a setup already running a TSP Medium Compression Head and TSP ECU tune.
More Than Just Looks
The TSP Oversize Powervalve Cover improves the appearance of your motorcycle, but its primary purpose is performance.
Unlike purely cosmetic aftermarket covers, the TSP design has been engineered around the volume and function of the internal chamber to produce measurable performance improvements.
It is particularly well suited to riders who want:
- More usable torque at low RPM
- Better control at low throttle
- Smoother power delivery
- Less need to rev the engine
- Improved performance in technical terrain
- Stronger low/mid-range response
Complete Your TBI Performance Setup
For maximum performance, the TSP Oversize Powervalve Cover can be combined with other TSP performance products such as a TSP ECU tune and TSP Billet Head.
These components work together to optimise combustion, fuelling and power delivery throughout the rev range.
Important Information
This product is designed for compatible 250 and 300 TBI models from 2023 onwards. Please confirm your exact motorcycle model and year before ordering.
The cover is compatible with stock and aftermarket pipes.
NB:
Please note that because we sell across multiple platforms, stock availability cannot be guaranteed. If an ordered item is out of stock, it will be placed on backorder and dispatched as soon as it arrives. If an item is permanently unavailable, we will issue a full refund.
Additionally, as most of our products are imported, final pricing is subject to change without notice due to fluctuating exchange rates and shipping costs.
We appreciate your understanding and always strive to process and ship your orders as quickly as possible!
