Piston Removal & Installation

Guide

Piston removal & installation

Difficulty: Advanced Time: ~60 min Applies to: Gas boards Last updated: Sep 2026

Watch the walkthrough

Watch on YouTube ↗ · JETSURF Service Tutorials #10. Timestamps in the steps below follow the video's on-screen counter (0:44–4:34).

This is a rebuild job — piston, ring, small-end bearing. Every part here has an orientation that matters: the aluminum washers, the piston pin, the ring, and the clips. Work slowly and keep the crankcase covered. Cylinder head torque is 7 Nm.

Tools & supplies

Needle-nose pliers
Two-stroke oil (for lubrication on assembly)
Grease (combustion chamber cap)
Torque wrench (7 Nm)
New piston pin retaining clips
New piston ring and aluminum washers as needed
Clean rag to block the crankcase opening

Removal

0:44 — With needle-nose pliers, remove the retaining clip and tap the piston pin out. Do not let the clip drop into the crankcase.

Installation

0:55 — Lubricate the small end of the connecting rod, ideally with two-stroke oil.
1:07 — Fit the connecting-rod bearing. Lubricate the piston pin and both pin bores in the piston.
1:23 — Slide the bearing toward the connecting rod and set the aluminum washer next to it — flat side facing the bearing, rounded side toward the piston.
1:32 — Partially insert the piston pin from the side where the piston has the drilled hole for exhaust-port-divider lubrication.
1:40 — Place the second aluminum washer inside the piston, rounded side facing the piston.
1:53 — Slide the piston onto the connecting-rod bearing and push the pin fully through.
2:07 — Install the first retaining clip — always on the side where the piston ring locator pin is positioned.
2:27 — Install the second retaining clip.
2:30 — Fit the piston ring with the end mark facing up. The lubrication channel faces the exhaust-port side; the ring gap lock sits on the freewheel side.
2:47 — Lubricate the cylinder with oil and slide the piston into the cylinder.
3:31 — Tighten the cylinder bolts with a wrench, alternating in a crisscross pattern.
3:58 — Apply grease to the combustion chamber cap and set it onto the cylinder.
4:11 — Fit the cylinder head and start the six bolts.
4:34 — Tighten the head bolts to 7 Nm, in the same crisscross pattern.

Tip: get every orientation right before the pin goes through — washers (flat to bearing, rounded to piston), pin entry on the lube-hole side, ring end mark up, ring gap lock on the freewheel side. Once the clips are in, checking any of that means pulling it apart again.

Caution: stuff a clean rag into the crankcase opening before you touch the clips — a clip dropped into the crankcase means splitting the cases to get it out. Use new retaining clips every time, and don't exceed 7 Nm on the head bolts.

Piston removal & installation