I currently have my engine in bits and Iam going to give the crankcase inlet and scavenge ports a clean up and smooth out all the rough surfaces before I reassemble it. The intake ports have a kind of ramp in each inlet just before the crankcase with the right side one being wider than the left. I was wondering if any one knew if they restrict the bike in any way? I guess they are supposed to be there but I have stripped quite a few 2 strokes over the years and never seen anything similar.I have attached a link to a picture, if any one can shed any light on this I would be most grateful.

http://www.bikepics.com/pictures/507415

Take care brother Paul. Don't get rid of the ramps. well not completerly anyway.

Try taking a look at the ramps with the crank fitted and you'll get an idea as to what they're actually there for. Don't go hacking away 'cos you may end up spoiling it.

Think smooth smooth smooth. Sharp corners are not good, but radii are.

Check out the mismatch between case and transfers.

Don't attempt to cut into the transfers unless you have all the right tools to get into the corners and out of sight places. You can quite easily ruin the shape and upset the flow. Honda do a reasonable job, but there's still some casting flashing that can be trimmed down.

Don't knife edge the bridge between the main and 5th transfers. A small rad here is better.

Thanks for that Matt,you can rest easy i wont be hacking any lumps off of the ramps then, my main aim was just to smooth things out and blend in the transfer ports at the case/barrel interface.At the rear of the barrel is a small rectangular port that mates with a similar port in the case but the port in the barrel is about 1mm smaller all around than the opening in the case, would you suggest chamfering this to match the cases?Thanks again!

Opening up the rear transfer to match the case is a good thing and helps reduce turbulence in the port. Flow the port in gently and carefully. It won't increase flow as such because you're not actually increasing the port window size, but it will allow the port to flow as it's supposed to.

Thanks again for the reply Matt thats a great help, time to get busy with the files!!!