Post by wibble on Oct 31, 2017 20:07:43 GMT
hello,
found a page on the Wiseco website that has some nifty info to help piston lubrication
Drilling Lubrication Holes
Make sure you have the instruction sheet that came with your new piston. This drilling information can also be found there, complete with a visual diagram.
1. Install the piston and wrist pin on the connecting rod with one circlip. Make sure the arrow stamped on the dome of the piston is facing the exhaust side of the cylinder.
2. Slide the cylinder over the piston until the cylinder is in its normal position on the crankcase
3. Slowly turn the engine over until the bottom ring groove (or the only ring groove if your piston has only one) on the piston is at the top of the exhaust bridge. You can look through the exhaust port of the cylinder to help know when the piston is in the correct spot.
4. Go through the exhaust port with a pencil and trace a line on the piston skirt for each side of the exhaust bridge.
5. Once the lines are traced and visible, remove the cylinder and the piston.
6. Start .300” below the bottom ring groove and mark two points .375” apart from each other. Make sure the points are centered horizontally between the two lines you traced.
7. Drill two holes .060” - .090” in diameter (1/16” or 5/64” drill bit) on your marked points (one hole on each point)
8. Remove all burrs from drilling the lubrication holes. On the inside of the piston, lightly sand with 400-600 grit sand paper. On the outside of the piston, use a ¼” drill bit and twirl it between your fingers over the holes you drilled to break away any edges and imperfections.
9. Wash the cylinder and piston with soap and water, and use compressed air to remove any water and debris.
10. Wipe the cylinder wall with light coat of oil. Whichever 2-cycle oil you normally use is fine.
11. Continue your top end rebuild as normal.
enjoy: blog.wiseco.com/two-stroke-how-to-relieving-the-exhaust-bridge-and-drilling-lubrication-holes
found a page on the Wiseco website that has some nifty info to help piston lubrication
Drilling Lubrication Holes
Make sure you have the instruction sheet that came with your new piston. This drilling information can also be found there, complete with a visual diagram.
1. Install the piston and wrist pin on the connecting rod with one circlip. Make sure the arrow stamped on the dome of the piston is facing the exhaust side of the cylinder.
2. Slide the cylinder over the piston until the cylinder is in its normal position on the crankcase
3. Slowly turn the engine over until the bottom ring groove (or the only ring groove if your piston has only one) on the piston is at the top of the exhaust bridge. You can look through the exhaust port of the cylinder to help know when the piston is in the correct spot.
4. Go through the exhaust port with a pencil and trace a line on the piston skirt for each side of the exhaust bridge.
5. Once the lines are traced and visible, remove the cylinder and the piston.
6. Start .300” below the bottom ring groove and mark two points .375” apart from each other. Make sure the points are centered horizontally between the two lines you traced.
7. Drill two holes .060” - .090” in diameter (1/16” or 5/64” drill bit) on your marked points (one hole on each point)
8. Remove all burrs from drilling the lubrication holes. On the inside of the piston, lightly sand with 400-600 grit sand paper. On the outside of the piston, use a ¼” drill bit and twirl it between your fingers over the holes you drilled to break away any edges and imperfections.
9. Wash the cylinder and piston with soap and water, and use compressed air to remove any water and debris.
10. Wipe the cylinder wall with light coat of oil. Whichever 2-cycle oil you normally use is fine.
11. Continue your top end rebuild as normal.
enjoy: blog.wiseco.com/two-stroke-how-to-relieving-the-exhaust-bridge-and-drilling-lubrication-holes