davewallace, I used my digital camera software to email photos to your email address. I thought they went out, but now that I know you didn't get them, I will check in to what I am doing. I remember the picture of the carb spacer you show here, but it didn't register, I guess it looked too big to be a Toro spacer. I am going to look at mine again to see if it looks like yours. The intake port on a 1 bbl Toro is huge, I don't think it needs to be enlarged at all, but the exhaust port seems as though it can use a bit of help, so I worked the exhaust over on the one I am testing. I checked the gaskets as you reminded me of, I had looked at them before, they wern't leaking, but I noticed that the cylinder base gasket could ft better so I made a new one. After I put the cylinder back on, I wondered if I shouldn't have put some Form a Gasket at the "T" of the base and case gaskets. Anyhow it wasn't leaking and the magneto seemed to be giving me trouble. After a while, it quit, I changed it and ran again. It only gives me 7500 RPMs but idles well and transitions well with the Zama carb that you thought could be too big, but the same carburetor works great on two 21cc and one 25cc Weeedeaters and they run great. This particular engine seems to have too much end play on the crank, I need to look at that. I have a couple of 5/8" Walbros, maybe I will try one to see what the results are. These engines have the porting and the compression is high, maybe they can handle more carburetation?? I have been using Poulan oil at 32:1 so far. Have you seen any recommendations on the ratio of oil for these Toros? By the way, the 2 bbl engine has a domed piston, not real high, but still not flat.