BBR Motorsports, Inc

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BBR 88cc Flat Top Piston Bore Kit

411-HXR-5400

411-HXR-5210

411-HXR-5212

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BBR 88cc Flat Top Piston Bore Kit

QTY $369.95

Out of stock

bbrmotorsports.shop

Any additional options and/or replacement parts will be available at the bottom of this page

BBR 88cc Flat Top Piston Bore Kit

Convert your CRF/XR50 to an 88cc screamer with this complete kit. Everything is included to upgrade the performance of you mini-bike. This kit uses your stock CRF/XR50 cylinder head.

Also fits 1988-1999 Z50R with short piston.

Aluminum BBR cylinder
Special 52mm piston specially designed to work with your stock cylinder head's combustion chamber
BBR special grind camshaft take full advantage of the large piston for great performance
Special BBR tapered aluminum intake manifold adapts the large carb to the stock intake port size
18mm carb includes extra main and pilot jets for easy tuning
Also includes CR style throttle, cable, air filter and top end gasket kit

Installation Note 1: Throttle unit included with kit will only work with 7/8" handlebars and will not mount to stock XR/CRF50 handlebars. Stock handlebars are 3/4".

Installation Note 2: This kit will not work with the Honda XR/CRF70 or other big port cylinder heads. It is designed for the tiny combustion chamber of the OEM Honda XR/CRF50 cylinder head. The flat top piston dome will result in an extremely low compression ratio when combine with the XR/CRF70 type cylinder head. The result is a motor that makes less horsepower than stock. Click this link for the BBR bore kit for the CRF/XR70.

BBR General Jetting Guidelines Chart

Part Number	Image	Description	Price
411-HXR-5400		Bore Kit - 88cc FTP W/Cam & Carb Kit, XR/CRF50, 00-Present	$369.95	bbrmotorsports.shop

Replacement Parts

Part Number	Description	Price
411-HXR-5210	Gasket Kit - 88cc S/P-FTP Kit / XR/CRF50/70	$26.95	bbrmotorsports.shop
411-HXR-5212	Ring Set - 88cc/106cc S/P-FTP Kit / XR/CRF50/70	$41.95	bbrmotorsports.shop
411-HXR-5250	Cylinder - BBR Aluminum, 52mm / XR/CRF50	$163.95	bbrmotorsports.shop
411-HXR-5411	Piston Kit - 88cc FTP Bore Kit / XR/CRF50	$125.95	bbrmotorsports.shop
411-HXR-5416	Piston Pin - 88cc FTP Bore Kit / XR/CRF50	$16.95	bbrmotorsports.shop
411-HXR-5417	Piston Pin Clips (2) - 88cc FTP Bore Kit / XR/CRF50	$5.95	bbrmotorsports.shop
421-BBR-2001	Carburetor Only - 18mm (80m/35p)	$100.95	bbrmotorsports.shop
422-HXR-5003	Intake Manifold - XR/CRF50/PC18/Stock Head	$45.95	bbrmotorsports.shop
512-BBR-1001	Throttle Cable - BBR 18mm/26mm Carb Kit / XR/CRF50 / KLX/DRZ110 / Bar Kit - CRF110F / DRZ70	$29.95	bbrmotorsports.shop
512-BBR-2001	Throttle Assembly - BBR Carb Kits / Brake Kits	$22.95	bbrmotorsports.shop

Optional Parts

Part Number	Description	Price
410-HXR-5005	Clutch Springs - HD / XR/CRF50, 00-Present	$41.95	bbrmotorsports.shop
430-HXR-5002	Air Filter - UNI, 1 1/4"(32mm) X 4", Straight / 18mm Carb / XR/CRF70 Stock Carb	$26.95	bbrmotorsports.shop
451-HXR-5001	Rev Box - Honda / XR/CRF50/70/80/100	$99.95	bbrmotorsports.shop