The staggering on heavy throttle, with its distinctive miss, followed by a surge when the throttle is rolled off, sounds a lot like what is called 8 stoking. Which apparently takes place when the mixture is too rich. I think I will lower the needle and see what happens. Worse case scenario I need to remove the top of the carbs and raise it.
Here is another quote from John Healy: "8 stroking is when a 4 stroke engine is so rich it needs to go through another 4 cycles to get enough oxygen to produce a combustible fuel to air mixture. Instead of the engine producing a smooth brrrruuuummmmm... as it accelerates, it goes bah, bah, bah, bah. Often the 8 stroking will be accompanied by black smoke coming out the tail pipe."
A buddy rode behind me and told me he could smell gas in my exhaust. I'm thinking too rich.
Stephen Hill
