The timing gear and cams fitted to Laser engines are extremely robust and unlikely to give any problems. The backplate should not be taken apart unless absolutely necessary.
There are no markings on the cams or pinion drive fitted to Laser engines. With the single cylinder engines the cam followers will hold the cams in position if back plate is removed provided the cylinder head has not been removed.
The cams fitted to twin cylinder engines will generally come out if the backplate is removed.

LASER SINGLE CYLINDER ENGINES

Laser-61, 75, 80, 90,100, 120, and 150.
The two cams are identical and interchangeable.
The inlet starts opening at approximately 40⁰ before top dead centre. (BTDC)
The exhaust finally closes at approximately 30⁰ after top dead centre. (ATDC)

Laser-45, 50, 62, and 70.
The inlet cam has a sharper profile (it is more pointed) than the exhaust.
The inlet cam starts opening at approx. 30⁰ BTDC.
The exhaust cam finally closes at approx. 30⁰ ATDC

Picture shows cam on Laser-80 at top dead centre

Laser-180
The timing is symmetrical. Inlet starts opening at approx 35⁰ BTDC Exhaust closes 35⁰ ATDC

LASER TWIN CYLINDER ENGINES

150v, 180v, 200v, 240v 300v

There are three cams fitted to Laser twin cylinder engines. The inlet cam is a twin cam. (top centre in the picture). Fit this to start opening the inlet approximately 40⁰ BTDC on the right hand cylinder first. Next fit the exhaust valve for the right hand cylinder to close approx 30⁰ ATDC.
Rotate the crankshaft so the left hand cylinder inlet valve starts opening. Next fit the exhaust valve to finally close at approximately 30⁰ ATDC.

Picture shows Vee twin cams with left hand cylinder at top dead centre. Note position of exhaust cam.

To find top dead centre. A piece of wooden dowel or plastic can be inserted vertically through the glow plug hole to touch the piston. Rotating the crankshaft will push the dowel. Top dead centre will be at the highest point. Make a mark on the propeller driver and front housing to show this point.

Before running the engine turn the crankshaft over carefully. If the timing is not correct the valves may collide with the piston.

The timing can be reset at our factory. There will be a charge of £20.00 plus return postage for the Single cylinder engines plus return postage and £30.00 plus postage for the Twin cylinder engines.