If you send an email to the addy below, we can send you the instructions, which should have a parts list and diagram.

As far as glow plug usage, if you run the engine at the low RPM, it will tend to go through plugs. We normally ran an APC 12 x 7 or 8 prop on the SF-series engines, and turned them in the high-11,000's with the stock muffler. With a pipe, you may be able to get a bit more propeller with the same RPM.

Your fuel is just fine, and won't hurt a thing.