- MON-FRI
- SATURDAY
- 7AM-7PM
- 8AM-4PM
- MOUNTAIN TIME
- ¡Hablamos español!
Hi. Sign in
Account / Orders
Sign in or create an account to get RM cash on orders and open more site features.
Expand
Big Bore Kits
You are viewing a combination of machine-specific and universal parts. Please choose a machine to display parts specific to your machine or select a part below.
User Tip: If you're unsure of your vehicle type, you may skip the machine type selection box.
Big Bore Kits
Big Bore Kits
Latest Engine Reviews – You could win up to $500 for reviewing products!
Steahly Heavy Flywheel Weight
Kevin in TN
MX to technical trails.
At first, my boy was sour to the idea of losing engine acceleration, but after racing for an hour ion technical terrain, he told me to to leave it on. It prevented several stalls and provided more usable power for the type of racing is does.
Read All Reviews
Kibblewhite Valve Spring Kit
Joe in MT
Crf250 and Crf450 valves
Great figment and cheaper than Honda valves. Last and stay in spec also.
Read All Reviews
Vertex Piston Kit Standard
Paul in AB
Perfect fit
Top notch quality, fits perfect!!, highly recommend this piston and ring , compression is awesome, and loads of power
Read All Reviews
Hot Rods Bottom End Kit
Darrell in TX
Hot rods cranks are quality
Great product. With proper tooling, a breeze to install.
Read All Reviews
Wrench Rabbit Engine Rebuild Kit
john in ID
Awesome kit
I have been buying these kits for a few years from Rocky Mountain and they are by far the best kit out there. Rocky Mountain always has everything I need in stock
Read All Reviews
Pro X Piston Kit
Rick in CA
Pro X
2017 Ktm 300. Changed at 240 hours , 1 season later bike has 377 hours now. pro x makes a quality product been using these pistons since a I was 10 rebuilding my bikes with my pops in the garage.
Read All Reviews
