# TBParts - Vintage Honda 88cc Race Head big bore Kit CT70 K0 - 81

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

## Summary

- **Part number:** TBW0939-CT70K0-81
- **Price:** $419.99 USD
- **Stock:** Out of stock. It cannot be added to the cart right now. A person can ask to be emailed when it is back: [Get on the List](https://tboltusa.com/store/contact_us.php?pid=1441&stockcheck=true) ([Contact us](https://tboltusa.com/store/contact_us.md)) This is a kit: the count is how many complete kits can be built from the parts on hand.
- **Product id:** 1441
- **Product last changed:** 2025-06-03

## 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.

- [Honda Vintage Mini Bike Parts > CT70 > Engine Kits](https://tboltusa.com/store/ct70-engine-kits-c-101_91_555.md)
- [TB Parts > CT70 > CT70 Big Bore and Stroker kits](https://tboltusa.com/store/ct70-ct70-big-bore-and-stroker-kits-c-68_75_1039.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)

Same great quality CRF50/XR50 88cc kits now for Vintage

TB Race Head, 88cc Bore & 20mm Carb Kit

This is the Race Head 88 kit that everyone is talking about. Performance and Price make Mike's Honda Trail Bike 88 w/ Race head a real winner!

**Key Features:**

- Lightweight aluminum cylinder with steel sleeve
- Cast in mounts on cylinder for aftermarket skid plates
- Oversized cooling fins on cylinder for efficient heat dissipation
- 52mm piston with rings, pin, & clips
- High performance race camshaft for the race head
- Larger valves (25mm intake & 22mm exh) and porting for increased performance.
- Also has bigger cooling fins. Includes all necessary parts. Comes disassembled.
- 20mm Performance carb assembly

**Recommended:**

- High volume oil pump - TBW0225-6V
- High speed 2mm drill bit - TRC-5526
- 2 Size clutch tool - WHS-2274
- TB oil cooler kit w/ intake mount - TBW1370
- Sta-bil fuel stabilizer - W-57-1129
- 12 Way rotating spacer - TBW0900
- Pre-filter - OW-20-2159-01

**Application:**

- CT70 - K0-81

**Kit Includes:**

- TBW0219 - Piston
- TBW0206 - Gasket
- TBW0156 - Cylinder
- TBW0125 - Carb
- TBW0273 - Intake
- TBW0301 - Throttle Cable
- TBW0174 - Air Filter
- TBW0189 - Race Cam
- TBW0385 - Race Head & Valves Assembly
- TBW0294 - Jet Kit
- TBW0251 - Right Side Cover
- TBW0861 - Cam Sprocket

Installation Note: It will save a lot of time and effort if the oil pump is installed while installing the bore kit (requires cylinder removal).

NOTE Throttle cable is for CR type twist throttles

## 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

This item is out of stock, so it cannot go in the cart now (see Stock above).

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

## Photos

- [Photo 1](https://tboltusa.com/store/img/p/1441/tbparts-vintage-honda-88cc-race-head-big-bore-kit-ct70-k0-81-1.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.