After buying the bently manual the other paul smith and i were going to do a compression test, and why not change the spark plugs while were at it. Took out all 4plugs. Properly labeled wires. Read thatengine should be warm so we were going to put in new plugs and run her a bit. Battery was dead so we charged it. Today it wont run at all. Put old plugs back in to see if e could even get her running, but no go. We double checked the timing. Will turn over w starter, but yhe air filter is puffing out with a hissing noise. Help.