Harley Davidson Engine Firing Sequence

Instead of one piston firing every 360 degrees a Harley engine goes like this.

Harley davidson engine firing sequence. Number one fires 180 degrees later number 2 fires 540 degrees later number 1 fires again. Front Bang rotate 315 degrees - Rear Bang rotate 405 degrees - Front Bang rotate 315 degrees - Rear Bang etc. Engine firing order is the sequence of spark events that must occur for all cylinders to produce power.

The difference in the Harley engine is that the crankshaft has only one pin and both pistons connect to it. So there it is. That puts the rear cylinder into its power stroke and the front is on its intake suck stroke being pulled down by the crank.

The W3 uses its cubic inch to create the power thus keeping the package very reliable. V Engine Type. Here is an illustration of your crank shaft.

There are many possibilities of what you have. John Deere two cylinders are more uneven firing. Pump - Twin gerotor dual scavenge crank mounted and driven internal oil pump dry sump.

About 100 companies have made frames for Evo engines. A piston fires. To create this type of engine the crankshaft has two separate pins for the connecting rods from the pistons.

Fire-crank rotates 315fire-crank rotates 405fire-crank rotates 315fire-crank rotates 405 lather rinse repeat. The pins are 180 degrees apart from one another. Chuck the firing order of your 90 degree twin is 1-2.