I've got a long way to go. I need to purchase the engine and extra sleeve first. It may be a month before I get the funds for that.

I want to start out by installing the ring around the counterweight and filling the space to stuff the case.

What type of lightweight material can I use to take up that space? It needs to be fuelproof, but lightweight--so that it doesn't effect balance too much..

How will I get a ring built/welded to the right size to wrap around the counterweight?

I wonder if a very thin walled piece of pipe/copper/aluminum could be slightly undersized---then heated to expand it enough to slip over the counterweight. When it cooled off and shrunk--it would be like a press fit. But--there's not usually much room around the counterweight. It would have to be a VERY thin walled piece--to avoid rubbing on the crankcase.

Once the case is stuffed--then the fuel charges will be accelerated through the transfer ports. I can drill out the crankshaft hole to allow a bigger charge to be sucked in at those higher velocities.

Port matching is really all that I want to do to the transfer ports.

I would like to increase intake duration and raise the exhaust port to increase duration there as well.

I'm wondering if the carb will flow enough fuel?

On dremeling the clyinder sleeve:
TH states that this is a steel sleeve. Can I accomplish my grinding and port matching work with a carbide bit on my dremel? What types of tools do I need to grind on the sleeve?

On the case transfer ports:
Should I use fine emery cloth and polish the transfer ports in the case and make them shiny--or is it desireable to have leave them rough--to turbulate the fuel charges as they enter the combustion area?

Should the tops of the transfer ports in the case and sleeve be ground to a more aggresive angle to allow for smoother flow?

I bet that you can tell that I've never done this many mods to an engine before.[:-]

I've drilled a crankshaft on a 61FX once and also attacked the exhaust port on that same engine. I was pretty amazed at the boost in performance.

If You guys can help me out--and tell me what kinds of grinding tools I need. As well as where and how much to take off here and there--I'll follow directions.

I've searched around for numbers and figures on intake and exhaust durations--but not having much luck. I know that there is a point of diminishing return on the durations, but can't find the numbers.

I guess the best place to start is to buy the engine and post the stock timing specs.