# FMF - Factory 4.1 RCT MINI S/O for Honda CRF125F 2019-Present

> This is a plain-text (markdown) copy of a page on tboltusa.com, made for AI assistants. People see the same page at the HTML link below.

- **Breadcrumbs:** [Home](https://tboltusa.com/store/index.md) > [Japanese Mini Bike Parts](https://tboltusa.com/store/japanese-mini-bike-parts-c-100.md) > [CRF125F](https://tboltusa.com/store/japanese-mini-bike-parts-crf125f-c-100_1090.md) > FMF - Factory 4.1 RCT MINI S/O for Honda CRF125F 2019-Present
- **Web page:** [this page on tboltusa.com](https://tboltusa.com/store/fmf-factory-41-rct-mini-so-for-honda-crf125f-2019-present-p-11356.html)
- **Markdown:** [this page as markdown](https://tboltusa.com/store/fmf-factory-41-rct-mini-so-for-honda-crf125f-2019-present-p-11356.md)
- **Generated:** 2026-11-06 21:16 EST
- **Site guide for AI assistants:** [llms.txt](https://tboltusa.com/llms.txt)
- **Your list:** To list everything you have looked at in one page, with current prices and stock, add ids to this address (comma separated, up to 20 of each): `https://tboltusa.com/store/seen.md?p=11356`

All prices are in US dollars (USD). Shipping and any tax are worked out at checkout.

## Summary

- **Part number:** W-79-41595-D
- **Price:** $349.99 USD
- **Stock:** 1 left.
- **Product id:** 11356
- **Product last changed:** 2024-05-20

## What it fits

The store lists a part under each bike or engine model it is meant for (the categories below) and may name models in the description. Do not assume it fits a bike or engine that is not named here; ask the store first.

- [Japanese Mini Bike Parts > CRF125F](https://tboltusa.com/store/japanese-mini-bike-parts-crf125f-c-100_1090.md)

Where a fitment line says "All", it means all years of the model named on that line, not all bikes.

## Description (the store's own text)

The Factory 4.1 RCT incorporates the latest in FMF Resonance Chamber Technology™ both internally and externally. In addition, we achieve a shorter overall length that is less susceptible to crash damage and complementary to our Factory Forward Engineering - moving the muffler closer to the motor to centralize mass. The Factory 4.1 RCT is constructed from only aerospace grade materials that meet our exacting specifications and is manufactured 100% at our Southern California factory.

**Key Features:**

- Massive Power gains throughout the RPM range.
- Huge weight savings
- New RTS (Rapid Tuning System)
- FMF uses the highest quality proprietary blend of alloy grade titanium made especially to our standards.
- Can be used with FMF or Stock OEM Header

## Shipping and returns

- Flat rate shipping is $8 for parts orders under $75 and free for most parts orders over $75, within the continental 48 states. Heavy items (engines, complete bikes, suspension) are excluded.
- Full shipping policy: [Shipping policies](https://tboltusa.com/store/shipping-policies-i-6.md)
- Returns: the store's own policy page says how returns, exchanges and cancellations work. Please read it before buying: [Returns, Exchanges and Cancellations](https://tboltusa.com/store/returns-exchanges-and-cancellations-i-11.md) The page begins: "All products returned to T Bolt USA must be reviewed and approved."

## How to buy

For a person: open [FMF - Factory 4.1 RCT MINI S/O for Honda CRF125F 2019-Present](https://tboltusa.com/store/fmf-factory-41-rct-mini-so-for-honda-crf125f-2019-present-p-11356.html), choose any options, press "Add to Cart", then check out from the cart. Payment is only ever entered by the person, on tboltusa.com's own checkout pages.

For an AI assistant building a cart: `https://tboltusa.com/cart/new/item/11356/qty/1` starts one with this product (the first value of every option, qty 1), `https://tboltusa.com/cart/<cart_code>/add/item/11356/qty/1` adds it to a cart you already started, and `https://tboltusa.com/cart/<cart_code>/zip/<ZIP>` gives the shipping options to a US ZIP code. They answer JSON: give your customer the newest `cart_link`, a public cart link, safe to share.

Or give the person one link that fills their own cart when they open it (a public cart link, safe to share; the first value of every option, qty 1): [Put FMF - Factory 4.1 RCT MINI S/O for Honda CRF125F 2019-Present in my cart](https://tboltusa.com/cart/open/item/11356/qty/1)

Payment: all major credit cards, PayPal, Apple Pay and Google Pay. Money orders by arrangement.

Cart: [Shopping cart](https://tboltusa.com/store/shopping_cart.php)

## Photos

- [Photo 1](https://tboltusa.com/store/img/p/11356/fmf-factory-41-rct-mini-so-for-honda-crf125f-2019-present-1.jpg)

## Support

Since 2004, every purchase from TBolt USA includes access to technical support from our staff of experts and our online [Pit Bike Technical Info Database](https://tboltusa.com/store/tbolt-usa-pit-bike-minimoto-technical-info-database-tech-15.md)!

We have all necessary support parts on hand.

*Most* orders ship same, or next business day, unless otherwise noted above.