● This 60mm Yuminashi 164cc Flat Deck Light Bore cylinder kit is as good as it gets because all really important details have been worked out by the Yuminashi R&D to introduce you a perfect and powerful big bore kit specifically designed for the stock 125cc engine and cylinderhead with 22/27mm valves!!
164CC FLAT DECK CYLINDER BLOCK (FOR 125CC HEAD)
● The all-original Yuminashi 164cc Flat Deck cylinder block with larger water/coolant capacity has been developed by the Yuminashi R&D to have a cooler running engine which is able to run higher compression ratios without the fear of blowing head gaskets and to push the envelope on the durability and reliability side as much as possible with installing a entirely new very hard cylinder sleeve which comes directly from the Yuminashi racing series engines to avoid ovalisation, oil leaks and compression loss!...
If you would install a bored up PCX150, a SH150 or a bored up VARIO150 cylinder block on your 125cc engine, then you would be faced with the issue that the water cooling circulation canals in your 125cc cylinderhead don't match with the once in a stock 150cc gasket and stock 150cc cylinder block.
The Yuminashi 150cc Flat Deck Light Bore kit with the 60mm 164cc cylinder block and special copper head gasket will make the perfect fit for your stock eSP 125cc cylinder head!...
Because the 164cc cylinder block from this light bore kit is mentioned for the 125cc head and engine, the 60mm engine block comes with 124cm marked on the cylinder block!
The cylinder block in this set is mentioned for the eSP generation 125cc engines, so this cylinder have 3 pins on the cylinder to install the eSP engine ignition coil bracket.
The outer diameter from the cylinder sleeve has the correct diameter to fit plug & play in your stock eSP 125cc crankcase.
60MM LIGHT BORE PISTON
The enlightened piston is made from A-grade materials and the piston skirts come with a molybdenum coating.
The 60mm piston from this set has a 13mm piston pin and is entirely balanced to ensure you a very safe and powerful combo with the stock 125cc cylinder head installed.
The flat top of the piston guarantees you the absolute right compressions ratio straight out of the box without any risk on detonation (engine knock) issues.
The both sides of the piston come with machined oil lubrication grooves to guarantee your 164cc kit optimal piston lubrication!
The valve pockets in the piston are prepared to run with stock 27/22mm valves from the stock 125cc cylinderhead with 0.05mm IN / 0.08mm EX cam clearance.
HARD CHROMIUM PLATING LAYERED (Cr) PISTON RINGS
The hard chromium plating layered (Cr) piston rings which are produced by very strict Japanese standards has excellent characteristics which combine the original properties of chromium metal with the advantages of erectro-deposits!
The main benefits from the chrominum plating layered piston rings are extermely high hardness of HmV (Micro Vickers), 800 to 1100 (cf. gray cast iron 220 to 270), high melting point of approx. 1800°C (cf. cast iron 1200°C), good thermal conductivity and corrosion resistance, a low friction factor and excellent wear resistance, such features are very effective in preventing piston ring wear.
60MM COPPER GASKET SET FOR 125CC HEAD (0.3mm)
With the 0.3mm thin copper head gasket you are ensured from the perfect seal because the 0.3mm thin copper head gaskets have a much better sealing characteristic compared to the stock material used to produce the stock head gaskets which makes the copper head gaskets the preferred gaskets for engine tuners with high compression big bore setups.
The reason why all Yuminashi big bore kits are coming with the full copper gaskets sets is because Yuminashi knows that the one thing no engine builder wants to worry about is a head gasket failure, whether it is a NASCAR cup engine, a Pro Stock drag racing engine, a dirt track engine, a hot street engine or even a stock engine. Stock head gaskets hold up well enough under normal loads. But as compression ratios and combustion pressures go up, a stock head gasket may not be able to maintain a leak-free seal. And once hot combustion gasses start blowing past the gasket’s combustion armor, bad things begin to happen. The combustion armor cracks or burns through, compression is lost and the gasket fails. Or, oil start finding new ways to circulate inside the engine, often with negative consequences.
For many years, serious racers have considered copper head gaskets to be the hot setup for high horsepower engines and most top fuel dragsters and funny cars run copper head gaskets because nothing else works.
Therefor, all Yuminashi big bore kits come complete with the full copper head gaskets in the box to make sure your head gasket will be able to make the perfect leak-free seal...
The 60mm copper head gasket which comes with the 164cc Flat Deck Light Bore kit is a special gasket mentioned to make the perfect fit on the stock 125cc cylinder head.
The head gasket set includes:
- 1 Copper head gasket, 60mm for eSP 125cc head
- 1 Cylinder base gasket for eSP 125cc engine
- 1 Cam chain tensioner gasket.
CAUTION! This gasket set can't be used on a 150cc cylinderhead!...
The total 164cc Light Bore Kit includes:
- 1 Light bore piston, 60mm with 13mm pin
- 1 Flat Deck Cylinder, 164cc for 125cc head
- 1 Gasket set which includes copper cylinder head gasket, cylinder gasket and cam chain tensioner gasket.
This Pro-Series 164cc big bore cylinder kit comes with free shipping worldwide!
*It is recommended to install the larger 6-holes high performance fuel injector in combination with this set to avoid a lean running engine!
365 Days full factory warranty (Not applicable for racing use!)
All prices are in USD