Ok guys,. I made a few changes, maybe too many at once, but I'll be trying it this weekend.
I added the internal stinger to the pipe making the ID .2845. I ran the internal stinger to just about in line with the widest point on the pipe. I added a litte more water restriction with a small tie wrap just above the rudder. I adjusted the remote needle set up because I was just about as lean as I could go. I turned the screw in about 1/2 turn and adjusted the setting back to about mid range of the throw. This will give me the range I need to go a little leaner if needed.
I also added a tiny bit of negative strut angle on someone elses advice.
I realize this is too many changes to make at once. hopefully I don't go backwards!!!!
Thoughts?
Don't worry about making the engine leaner. You've ALREADY been too lean, because you did blow a plug. What you want to do is burn more fuel. Restricting the water alone will help that. Also shorten the pipe more. Cut the header as short as possible and taper the inside end of it. Take the dremel to it and carve a taper down in there about 3/8" to 1/2" if you can get that far. Next cut that 1/4" of header section off your OPS pipe so that the engine header butts to the cone of the pipe. You can cut a couple of shallow grooves on the OD of the pipe to help the silicon coupler maintain a good grip and not slide off. This will get your rpm up and also burn more fuel too.
Drill a .040" diameter hole in the back of the rudder until it meets the water pick up hole going up the back of the blade. Do this just below the water fitting. This will act as a pressure relief valve and eliminate the possibility of blowing out the water line. It will also make the tie wrap adjusting less sensitive. You will still get plenty of water pressure for even the hottest weather when you do need more water flow. Tie wraps are good for a last resort when you are at the pond and need to make an adjustment, but there are several other options that are much more accurate.
The smaller stinger will give you more tank pressure, so it is good that your gave yourself more room to lean the needle.
If you have a lathe available it would be a good idea to cut about .015" off the squish band and recut the shoulder to get the correct head clearance. Look for a plug depth of .105". There are other ways to mod the head, but that suggestion works for a wide range of variables with 50 to 70% nitro.
Try to keep the H.C. closer to .007-.008" if you go up to 60% nitro. .008"-.010" is ok for 50%.
These are things that will get you more speed without spending money for new parts.
I'm grapling with one part here - though: "Also shorten the pipe more. Cut the header as short as possible and taper the inside end of it. Take the dremel to it and carve a taper down in there about 3/8" to 1/2" if you can get that far. Next cut that 1/4" of header section off your OPS pipe so that the engine header butts to the cone of the pipe. You can cut a couple of shallow grooves on the OD of the pipe to help the silicon coupler maintain a good grip and not slide off"..
