Our 75 hp 4 stroke has suddenly decided not to run properly. Hard to start and will turn only 3500RPM at WOT with a rattle. Plugs are all clean and dry, the carbs have been recently rebuilt. There were tons of dirt-dobber nests inside the cowling, and I'm concerned it may have "Jumped time". The timing marks with an arrow and "T" do not align on the cam and crank pulleys. Is this a reasonable possibility? Are the marks supposed to align?

Hi,
The rattle sound might be a loosen timing pulley (it is written fly wheel on mine)....
It just happened to me on my 9,9 hp.....

The timing pulley from the crankshaft loosened up so much that the timing belt got out of it in the middle of the lake.....check it out before it happens to you.....
And when the timing belt got off the timing pulley, I lost the woodruff key so i couldn't put it back...it was a long way rowing home....

GOod luck.

Lucas