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Top End Engine Rebuild Kit - 300cc - Sherco 2011 to 2022 (+ Scorpa 2015 to 2022)
Top end rebuild kit including the piston, gaskets and O-rings
For the Sherco ST300 trials bikes from 2011 to 2022.
Plus the Scorpa Twenty SC300 from 2015 to 2022.
Please note the later bikes came with the 2 piece Oxia insert style head fitted these use the 31x2.5 Viton Cylinder Head Insert O-ring, if you have an earlier bike with the cast head this is not required, there is also a M5 sealing washer used on the bleed screw, again you can remove 1 of these if you have a cast head.
Please select the piston letter size and base gasket size required to suit your bike, each bike is different, the base gasket do come stacked up to 3 high from the Factory.
Piston Sizes
Letter | Size | Part number |
---|---|---|
A | 78.95mm | 3218 |
B | 78.96mm | 3339 |
C | 78.97mm |
The factory recommended piston to cylinder tolerance for the 300 is 0.05mm, if you are considering putting the next size up piston in please be aware that your original piston will have worn down and any wear in the cylinder is unlikely to be uniform down the bore so please check the bore size all the way down the cylinder and from left to right as well as front to back, the factory measure the piston and cylinders at 24 degrees C. The piston is measured front to back and 19mm up from the bottom of the skirt, be aware that the pistons are manufacture tapered (larger at the bottom) and oval (larger front to back) to allow for unequal expansion of the piston in use.
18mm Gudgeon Pin by 56mm long
Centre of the gudgeon pin to the top edge of the piston 28.8mm
Overall height 66mm
Weight including rings, gudgeon pin and C-clips 280 grams
The base gaskets are available in different thicknesses to allow the correct squish clearance to be achieved. The standard gasket is 0.5mm thick and is commonly used with one of the thinner shim gasket, some bikes even come from the factory with 3 gaskets.
We recommend you set your squish (the gap between the top edge of the piston and the cylinder head) to around 1.30mm.
Manufacturer | Sherco |
---|---|
Year | 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022 |
Model | 300 |
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Sherco Bottom End Engine Rebuild Kit - 250, 290 & 300cc - 2011>2022
Starting at £1.99