✓ VERIFIED
Jun 21, 2017
product is shipped without crankcase ventilation parts that are clearly part of kit.
S&S CYCLE
SKU: T14-619449
S&S Cycle 1250cc Conversion Kit - Harley Sportster
$1,008.95
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About S&S Cycle
S&S Cycle has built American V-twin performance parts in Viola, Wisconsin since 1958 — flywheels, carburetors, cams, cylinder heads and complete crate engines. When a Harley owner talks about a 124, a 128 or a 131 build, they are usually talking about S&S. Few names carry more weight with engine builders in this space.
Transform your Harley Sportster's performance with the S&S Cycle 1250cc conversion kit. This kit is engineered to upgrade both 883cc and 1200cc Sportster engines, delivering a significant boost in displacement. It's a true bolt-on solution, eliminating the need for cylinder machining or piston rebalancing.
Why riders pick this
- Converts 883cc or 1200cc Sportster to 1250cc
- Includes S&S 3-9/16" bore cylinders
- Features forged flat-top pistons with coated skirts
- Complete gasket set and assembly lube included
- Requires no machining or piston rebalancing
For Sportster riders craving more power and torque, the S&S Cycle 1250cc conversion kit is a game-changer. This comprehensive kit provides everything needed to bump your engine's displacement, turning your stock 883cc or 1200cc into a potent 1250cc powerplant. It's designed for riders who want a noticeable performance improvement without the hassle of complex engine work.
Effortless Power Upgrade
- Converts 883cc or 1200cc Sportster engines to 1250cc
- Includes high-quality S&S 3-9/16" bore cylinders
- Features durable forged flat-top pistons with coated skirts
- Complete gasket set and assembly lube for a seamless installation
- No machining or piston rebalancing required for installation
Built for the Road
The S&S Cycle 1250cc conversion kit is engineered for reliability and performance. The inclusion of forged pistons ensures durability under increased power, while the coated skirts reduce friction. This kit is a popular choice for Sportster owners looking to make their bike feel more responsive and powerful on the street or track. Note that 883cc cylinder heads are not compatible with this kit and must be replaced.
Specifications
- Brand: S&S Cycle
- Manufacturer Part #: 910-0691
- Displacement Upgrade: 883cc or 1200cc to 1250cc
- Piston Bore: 3-9/16 inch
- Weight: 21.5 lb
- Category: Engine Components / Piston Sets - Powersports
Common questions
Will this kit work with my 883cc Sportster?
Yes, this S&S Cycle kit will convert your 883cc Sportster engine to 1250cc. However, you will need to replace your 883cc cylinder heads as they are not compatible with this kit.
Do I need to machine my cylinders or rebalance my pistons with this kit?
No, this S&S Cycle conversion kit is designed for bolt-on installation and does not require cylinder machining or piston rebalancing.
What's included in the conversion kit?
The kit includes S&S 3-9/16" bore cylinders, forged flat-top pistons with coated skirts, a complete gasket set (head, base, exhaust), assembly lube, and detailed instructions.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | S&S Cycle |
| TYPE | Piston Sets - Powersports |
| SKU | T14-619449 |
| WEIGHT | 21.5 lb |
Please contact us to confirm fitment for your specific motorcycle, or check the product title for compatibility notes.
CUSTOMER REVIEWS
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✓ VERIFIED
Nov 6, 2025
After much fabrication and alternative parts, it is installed. Not having a manifold ported for a map sensor complicates things significantly. I wasn’t going to settle for some pro rated refund because it was out of box. Much work left to do, but I’m committed to making it work.
✓ VERIFIED
Aug 5, 2022
Havent put it on yet but if its as good as the customer service i recieved getting the carb itll be breezy!
✓ VERIFIED
Apr 8, 2021
Fast shipping and it is in stalled runs great
✓ VERIFIED
Dec 3, 2020
Carb was installed per the O.E.M. Instructions, set-up and it runs and performs better than new! The JP Cycle online order was perfect!
✓ VERIFIED
Sep 14, 2020
I love the upgraded carburetor and intake system S&S .. great product and great addition too my harley.
