Building a reliable engine that is still capable of creating usable horsepower can be difficult for other tuners. Luckily for our customers, we have more than three decades of experience building and tuning performance engines that help riders stay on the track and win races. Many hours have been spent at the track and in our dyno rooms looking for ways to add reliability and winning performance into every customer's engine that shows up in our shop. We take pride in building some of the fastest and most dependable racing engines in the world for two-stroke and four-stroke dirt bikes.

Next to the full-sized engines, mini bike engines also find their way to our service benches looking for improvements. We've been a long-time supporter of the mini riders; many of which have gone on to become some of the biggest names in the sport such as Ricky Carmichael, Ryan Villopoto and Adam Cianciarulo. Mini bike modifications are in high-demand for amateur events, especially our supermini engines. Any Honda, Husqvarna, Kawasaki, KTM, Suzuki or Yamaha mini engine will benefit from one of our engine modifications.

Before you send in your engine, download our service form for your bike, print it, fill it out and send it along with your motor. A sales representative will call you once it is received to go over the work you want done. Please allow 5-7 business days for your motor modifications (turn-around times may vary). Once your work is completed, your sales representative will call you and go over the billing and shipping if it has not already been discussed. Our motor modifications department hours are from 9:00am - 5:00pm Pacific Standard Time.

Note: Prices, depending on bike/model may change or be different. For an accurate quote, please call Pro Circuit at (951) 738-8050 or email us at service@procircuit.com.

Note: All prices are subject to change. Not all modifications apply to all makes and models. Please call for specific details. Additional parts may be required for certain services and/or modifications. Hazmat fees not included.

1. Packaging: Pro Circuit recommends you visit your local UPS or FedEx store for shipping recommendations or contact our service department at (951) 738-8050.

2. Mark Your Engine: Please fill out our printable service form and include it with your engine.

3. Protect Your Engine: Pro Circuit recommends insuring your engine for at least $5,000. If you are shipping us a 4-stroke head or 2-stroke cylinder, we recommend ensuring it for the appropriate value of the parts.

Questions? Contact our shipping department for any questions you may have, or to learn how you can get the best rates on shipping! (951) 738-8050

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