[ThumperHumper]

I was wandering if anybody could help with timing the ignition on the 150F. Piston is at TDC, both valves closed. I have no idea where to start at timing the flywheel. Any help is appreciated.

[hondapunk53]

I was wandering if anybody could help with timing the ignition on the 150F. Piston is at TDC, both valves closed. I have no idea where to start at timing the flywheel. Any help is appreciated.

ask your local dealer or service center.

[Asmith]

The cam rotates 1/2 the speed of the crankshaft. So, at TDC the lobes can be up or down. True TDC is when the valves are closed, lobes down.

When the crank is at TDC and lobes are up, the engine is in "overlap" position. An easy way to tell if your engine is in overlap TDC or true TDC is to rotate the crank a few degrees in either direction (from TDC indicators). If in overlap, both valves will move. If in true TDC, there will be 0 valve action.

True TDC is where you adjust the valves per the book.

When the piston is at TDC the cam bolts should be nearly vertical, and the the cam sprocket timing marks should align with the parting line of the head and cam cover.

In most instances the cam will be positioned a bit retarded, or in visible terms the cam will be positioned just a bit "clockwise" from the above mentioned alignment.

As far as the flywheel goes, it is located with a woodruff key. It can only be installed correctly in one position. Heres a tip. The keyway in the crankshaft will align with the case markers when positioned at TDC. This can be of aid if setting cam timing with flywheel removed.