Briggs and Stratton 18.5 HP I/C timming?

Well the ignition timming is mostly based on the shear key that's on the crankshaft and the flywheel. If the ignition coil has been removed and now your installing it, the proper gap is between .012 to .014. you'll need a feeler gage to figure that out. If you have a point system on it, I really don't know the point gap, and you'll need to call your local small engine shop. All in all, that's really that briggs needs for ignition timming. If your talking about the camshaft timming, look at the small gear on the crankshaft and there will be a little dot that's been stamped onto the gear, the camshaft will also have a dot that's on it too. they are very distinct dots and not round imprented dots. Just rotate the crankshaft and the camshaft so that the dots align up and there you have it. What I do to check to make sure that the timming is right on, i'll rotate the crankshaft with the camgear in place and see where the piston is compared to the valves. You should see a total of four cycles with the intake valve open just as the piston starts to go down, this is the intake stroke and when the piston starts to move up, the intake valve should start to close and both valves should be closed as the piston moves up. this is the compression stroke. As the piston moves back down, both valves will still be closed, this is the ignition stroke and as the piston moves up again, you should see the exhaust valve open and that completes the final stroke which is to exhaust all the burnt gases from the ignition stroke, and this process will continue over and over again. I hope this helps!!!

David
July 2007