RS125 Performance Engine Parts

SP125 Limited
22 Walker Wood, Baildon, Shipley, West Yorkshire, BD17 5BE, England
*Telephone 01274 583231 steve@sp125racing.com* Mobile 07738 626165**

www.sp125racing.com

RS125 NEW ACCESSORIES, TUNING & PATTERN PARTS

Please 'Refresh' this page every time you visit.
If it is slow to reload, you know then that this page has been updated since your last visit.


LINE BORING STANDARD HONDA RS125 CRANKCASES

INSERT MAIN BEARING HOUSINGS & LINE BORE CRANKCASES	£450.00 + VAT
- Including fitting 2x GP Low Friction Main Bearings.

The Honda RS125 Crankcases are not supplied by Honda as a matched pair and because of this, often the crankcases are not in line.
Because of this, the crankshaft does not run in line through the main bearings and the conn-rod is not straight in line with the cylinder bore.
This leads to reduced engine performance and reduced bearing and crankshaft life.
We insert the crankcase main bearing housing, using HE30 Aluminium, then line bore to be sure that the main bearings and crankshaft are perfectly straight.
Also we machine straight and parallel the top of the crankcase/cylinder face.

INSERT CRANKSHAFT OIL SEAL HOUSING WHEN LINE BORING CRANKCASES	£40.00 + VAT per side
Occasionally, if the crankcases are badly out of line, it is also necessary to re-line the crankshaft oil seal housing.




HRC GEAR POSITION SENSOR

HONDA RS125 HRC GEAR POSITION SENSOR	£97.50 + VAT




CARBURETTOR BORE MODIFICATION TO 39.5mm

Standard carburettor bored to 39.5mm & Powerjet Nozzle modified to use 55 to 75 Powerjets	£225.00 + VAT
As used by our team bikes


A-KIT REED VALVE

HONDA RS125 A-KIT REED VALVE ASSY COMPLETE WITH A-KIT CARBON REED PETALS	£290.00 + VAT




A-KIT CARBON REEDS

HONDA RS125 A-KIT CARBON REED SET	£102.50 + VAT




REED SPLITTER

1995~2008 RS125 Reed Splitter - Fits Standard & Jha Reed Valve Assy	£125.00 + VAT
Slots straight into the reed valve and the Reeds then work independently of each other and reduces reed valve turbulence.
Dyno test have shown a gains throughout the power range, especially over-rev.
It is necessary to cut the rubber 'ears' off from the carb rubber.




Available for Honda RS125 & RS250 plus Yamaha TZ 250


JET HOLDER PLATE

RS125 Honda Jet Holder Plate	£38.00 + VAT




VHM ADJUSTABLE POWERJET FLOAT BOWL

The VHM PowerJet Carburettor Float Bowl has been designed with an adjustable PowerJet needle.	£325.00 + VAT
The PowerJet can be adjusted from approximately #0 up to #80 PowerJet sizes by simply adjusting the external screw.
1 turn of needle is equal to #40 PowerJet and 1 ¼ turns is equal to #45 PowerJet.
No need to remove the float bowl to make adjustments or change the PowerJets.

The standard PowerJet is not central in the carb float bowl.
Because of this, through long fast corners the standard PowerJet can draw air when the bike is leaned over and at fully open throttle,
as the standard PowerJet becomes higher than the fuel level in the standard float bowl.
This can cause detonation, as the PowerJet draws in air rather than fuel.

The VHM Float Bowl takes fuel from the centre of the float bowl.
The VHM Float Bowl has 2 channels, taking fuel from the centre of the bowl and then from the adjustable PowerJet screw needle.
This eliminates the possibility of the PowerJet drawing in air and eliminates detonation caused in long corners with the standard PowerJet system.




VHM A-KIT 'DOMED TOP' PISTONS & 0.8mm PISTON RINGS

New VHM A-Kit Domed Top Piston with 0.8 mm Piston Ring	£149.50 + VAT
This piston comes complete with 1x 0.8 mm piston ring, 1x piston pin & 2x clips

Designed specially for Honda RS125 and RS250 and used with standard Honda Small End Bearing 91101-NX5-023



Please note: The VHM A-Kit 'Domed Top' piston has been designed as a direct replacement for the discontinued HRC A-Kit 'Domed Top' Piston.
The piston is manufactured by Vertex.
There are many other different pistons manufactured by Vertex, mostly for Road or MotoX use.
But only the pistons having the VHM logo inside are designed and recommended for use in Honda RS125 or RS250.
Do not use other 0.80 mm piston ring or other piston pin or other clips with VHM pistons!


Please note: Production of the 'domed top' HRC A-Kit Pistons has now finished
HRC do not plan to make any more of these 'domed top' pistons and stock is now sold out.


VHM 'FLAT TOP' PISTONS & 0.7mm PISTON RINGS

The VHM pistons have been proven on various GP bikes and with good results.
These pistons weigh less than the standard pistons, which will improve engine over rev characteristics and give better throttle response.
The surface of the piston has a special roughness for better oiling, which will help to prevent premature seizure and damage.

New VHM flat top piston with 0.70 mm low friction piston ring	£139.50 + VAT
This piston comes complete with 1x 0.7 mm low friction piston ring + 2x clips
Must be used with special 41mm short piston pin - sold separately.
Designed specially for Honda RS125 and RS250 and used with standard Honda Small End Bearing 91101-NX5-023
Piston weight 117g



New VHM Special 41mm Piston Pin	£16.50 + VAT
Piston pin weight 28.2g


New VHM Special 0.7mm low friction Piston Ring	£21.00 + VAT
Piston ring weight 2.0g

New VHM Special Piston Circlip	£0.70 + VAT

Please note: The VHM 'Flat Top' piston has been designed as a direct replacement for the discontinued 2005 HRC 'Flat Top' Piston.
The piston is manufactured by Vertex.
There are many other different pistons manufactured by Vertex, mostly for Road or MotoX use.
But only the pistons having the VHM logo inside are designed and recommended for use in Honda RS125 or RS250.
Do not use other 0.70 mm piston ring or other piston pin or other clips with VHM pistons!


New 2008 HRC 'FLAT TOP' PISTONS & 0.7mm PISTON RINGS

New HRC 2008 Flat Top Piston	£167.50 + VAT
New HRC 2008 0.7mm Flat Top Piston Ring	£23.95 + VAT



Please note: The 2008 HRC 'Flat Top' piston & 0.7mm Piston ring has been designed as a direct replacement for the discontinued 2005 HRC 'Flat Top' Piston.


VHM 2 PIECE KIT CYLINDER HEADS
VHM UNIQUE PERFORMANCE ENHANCING STANDARD 2-PIECE CYLINDER HEAD DESIGN (Standard 5-Stud)	£225.00 + VAT

VHM UNIQUE PERFORMANCE ENHANCING A-KIT 2-PIECE CYLINDER HEAD DESIGN (A-Kit 6 Stud) 2007 spec	£225.00 + VAT

STD A-KIT


VHM INDIVIDUAL HEAD INSERT (11.20cc / 11.40cc / 11.60cc)	£49.50 + VAT
VHM INDIVIDUAL BLANK HEAD INSERT	£37.50 + VAT
VHM INDIVIDUAL SPECIAL MADE HEAD INSERT (All Head Volumes Available for Leaded & Unleaded Fuel)	£70.00 + VAT
VHM INDIVIDUAL SPECIAL MADE HEAD INSERT FOR 'FLAT-TOP' PISTON (Available for Leaded & Unleaded Fuel)	£70.00 + VAT
VHM INDIVIDUAL SPECIAL MADE HEAD INSERT FOR JHA KIT (Available for Leaded & Unleaded Fuel)	£70.00 + VAT
VHM INDIVIDUAL SPECIAL MADE HEAD INSERT FOR SEEL KIT (Available for Leaded & Unleaded Fuel)	£70.00 + VAT


'FLAT-TOP' VHM INSERT


VHM SQUISH, COMPRESSION & VOLUME MEASUREMENT TOOLS
VHM PISTON PROJECTION / SQUISH SETTING TOOL	£102.50 + VAT


An absolute 'must have' to achieve accurate squish, volume and port timing - go to VHM Tool Information


VHM PIPETTE / BURETTE (with adjuster for fine measurement)	£56.00 + VAT



* NEW *

NEW 2010 VHM CRANKSHAFTS

After the successful crankshaft AK20005(T), AK20015T and AK20017T, VHM have developed new models for 2010.
The crankshafts ware be available for the standard Honda RS125 and for the Honda RS125 A-kit.
The standard RS125 crankshaft will fit the standard crankcase, so there are no crankcase modifications needed.
The Honda RS125 A-kit crankshaft fits only on a Honda A-kit crankcase after modifications specified by VHM.
There are 3 models for the standard crankcase and 1 model for the A-kit crankcase.



The difference of the models of the crankshafts is the inertia and weight.
With the 3 type's of inertia, you can change the characteristics of the motor for each track.

Crankcase Model Part Number Description Type
Standard Crankcase 1 AK20109 RS125 crankshaft with Standard ignition Light weight Inertia	£1,595.00 + VAT
The crankshaft with a lower inertia reacts faster, which will increase the acceleration of the bike.
On short and slow racetracks, we advise to use the crankshaft with a lower inertia.

Standard Crankcase 2 AK20107A RS125 crankshaft with Standard ignition Middle weight Inertia	£1,595.00 + VAT

Standard Crankcase 3 AK20107B RS125 crankshaft with Standard ignition Heavy weight Inertia	£1,675.00 + VAT
Model 3 with the highest inertia reacts slower on the gas throttle when turning out of the corner.
The great advantage is that the rider can open the gas throttle earlier.
The risk of spinning of the rear wheel will be a lot smaller.
Another advantage of the higher inertia is that the top speed will increase due to the increased and improved over-revolution characteristic.
This crankshaft is heavier then the standard Honda crankshaft, but the crankshaft is designed so that the inertia
has increased relatively more then the mass of the crankshaft.

A-Kit Crankcase 4 AK20018 RS125 crankshaft A-kit Light weight Inertia	£1,695.00 + VAT

All VHM crankshaft has began a heat treatment and has been CNC grinded to precise dimensions.
The advantage of the heat treatment is that the crankshaft in totally will be a lot stiffer, because the resistance
against bending of the crankshaft is much bigger.
This results in a much longer performance and the crankshaft can also be overhauled many times.

To obtain maximum performance, the service limit for the VHM crankshaft is 1200 km running.
VHM can rebuild the crankshaft.
The crankshaft will be disassembled and the connecting rod, big end pin, needle bearing and side washers will be replaced.
After assembly, the crankshaft will be aligned with high accuracy.




VHM CRANKSHAFT REBUILD SET

* NEW *
CRK07 Crankshaft Rebuild Kit : for VHM crankshafts AK20015T, AK20017T, AK20109, AK20107A, AK20107B	£330.00 + VAT
The connecting rod kit consist of a billet VHM connecting rod, Ø24x54.9 big end pin, needle bearing and side washers. (Fits the Honda RS125 crankshaft)
AK20015T, AK20017T, AK20109, AK20107A, AK20107B

CRK01 Crankshaft Rebuild Kit : for VHM crankshaft AK20005(T)	£165.00 + VAT
The connecting rod kit consist of a connecting rod, Ø22x53 big end pin, needle bearing and side washers.
27.9 Inertia AK20005(T)

CRK03 Crankshaft Rebuild Kit : for standard Honda RS125 crankshaft 13300-NX4-711	£385.00 + VAT
The connecting rod kit consist of a connecting rod, Ø24x54.9 big end pin, needle bearing and side washers.
24.2 Inertia Standard Crankshaft 13300-NX4-711


VHM CRANKSHAFT REBUILDING CHARGE	£85.00 + VAT

VHM RETURN CRANKSHAFT SHIPMENT TO UK	£38.00 + VAT


FACTORY SAND CAST KIT CYLINDERS & BILLET CYLINDER HEADS
FACTORY SAND CAST A-KIT CYLINDER	£1,350.00 + VAT




BASE GASKETS
1998~2008 0.25mm BASE GASKET	£2.10 + VAT
1998~2008 0.75mm BASE GASKET	£2.35 + VAT



CYLINDER REPLATING & REPAIRS
RACING NIKASIL CYLINDER REPLATING - Coating to the highest standard - Includes Ports Dressing & Exhaust Bridge Relief	£140.00 + VAT
RACING PORTS DRESSING & EXHAUST BRIDGE RELIEF	£35.00 + VAT
RACING ALUMINIUM WELDING CYLINDER REPAIRS - crack repairs, detonation damage etc From	£35.00 + VAT
RACING DETONATION RING INSERT - Insert & Repair Detonation damage to cylinder	£75.00 + VAT




LOW FRICTION CRANKSHAFT MAIN BEARINGS
1995~2008 GP SPL LOW FRICTION CRANKSHAFT MAIN BEARINGS - Longer Life, High RPM Durability, Low Friction	£40.00 + VAT each

When we first got these, the GP Team claimed that they made a full 1 bhp extra power !
We run these for the full life of the crankshaft and replace at 1,200 miles (2,000 km) and they still look perfect.




ENGINE STANDS
1995~2008 ENGINE STAND - can be laid flat also	£80.00 + VAT




CLUTCH BASKETS
1995~2008 TALON BILLET HARD NICKEL PLATED OUTER CLUTCH BASKET	£99.00 + VAT
Much stronger than the original cast clutch baskets



1995~2008 HINSON BILLET OUTER CLUTCH BASKET	£235.00 + VAT
Improves clutch performance and life Improves heat dissipation Precision machined from billet T-6 aircraft quality aluminium to aerospace tolerances, and akadized for five times the wear resistance to stock.(with proper maintenance) Allows clutch assembly to spin more true creating less heat when clutch is disengaged.


1995~2008 HINSON REPLACEMENT CUSH DRIVE RUBBERS FOR STANDARD/TALON/HINSON CLUTCH BASKET	£29.75 + VAT


1995~2008 HINSON BILLET PRESSURE PLATE	£180.00 + VAT


DETONATION COUNTERS
HRC DETONATION COUNTER - With Data Logger Outlet - necessary to use with HRC DataLogger & HRC/Jha Ignition	£625.00 + VAT



HRC DETONATION SENSOR - replacement detonation sensor lead	£205.00 + VAT

Go To HRC Detonation Counter & DataLogger Page

DETONATION COUNTER	From £160.00 + VAT

Go To Detonation Counter Page


NGK SPARK PLUGS & CAPS
R6385-105P STANDARD SPARK PLUG	£45.00 + VAT
R7282-105 (R6120-105) RS250 'short' SPARK PLUG	£45.00 + VAT
R7282-105A / R7282-11A (R6120A-105 / R6120A-11) DETONATION COUNTER SPARK PLUG	£45.00 + VAT

R7282-105/105A/11A SPARK PLUG CAP	£20.50 + VAT




IGNITION CURVE CHANGERS
1995~2008 RS125 16 Setting IGNITION CURVE CHANGER	£245.00 + VAT
- Simple to fit to Standard ignition, boosting mid-range power and over rev.



Go To: 16 Setting Ignition Curve Changer



Exports of all parts supplied to outside EC Countries are exempt from UK VAT Exports to EC Countries are exempt from VAT if a valid VAT registration number is supplied



Return To sp125racing.com Homepage





SP125 Limited Disclaimer Honda, HRC and all other parts supplied by the SP125 Limited are not guaranteed when used in competition events. As such, it is a condition of our making all parts available that it is solely the decision of each individual, rider, team member or team whether they choose to use any part supplied and in doing so, absolve the manufacturer and SP125 Limited of any or all such claims, including damage to equipment and/or injury to personnel irrespective of how caused. All parts remain property of SP125 Limited until paid for in full. All 'special order' parts, that are ordered specially under the instruction of the customer, are non returnable and non refundable.