This is the 3rd engine for the 700 since I have owned it,the 22 years or so. The original model 19 was gone when I got the tractor,replaced with a well worn 19D. I ran it until it smoked like a diesel,then replaced it with a cast iron 8 hp short block that I had had for years. Not knowing if it was good or not,I stripped the parts that I needed off the 19D and put it in the tractor. It ran good for several years until last summer it developed a sudden serious knock. So I took two scrap yard model 23 D's,that I bought at our local show and swap meet,using the best parts from both I put a complete engine together and with a little modification to the tractor I put it in.
The model 23D is 2 inches taller and has a wider foot print.So I left out the factory spacer plates from the model 19,which put the crankshaft at the correct height.I drilled to new motor mount holes on the right side of the frame and had to enlarge the oil drain hole in the side of the frame to get it lower for the model 23D pan which is sitting right on the frame.I also had to "massage" the bottom front of the blower housing tin to get about a 1/2 more clearance.The only other real issue was I had to remove the oil fill tube because it wouldn't clear.I replaced it with a pipe plug but the clearance is still so tight that I had to grind the outside of the pipe plug down quite a bit.
The only things left now is to get or make low mount brackets to lower the starter/generator and I need to get lower the factory style oil bath air cleaner a little.I have different air cleaners that will fit and different air intake tubes but I haven't found a setup that suits me yet.
I'm in no hurry to put the starter/generator on because it starts right up in a pull or two of the rope cup but I would like it on by next summer.
This tractor should be stronger than ever now with the bigger model 23D and the tractor has the optional lower speed 8 inch drive pulley. Here are some pictures of the old tractor.