Re: HELP: broke 1979 20hp -will the lower from a 1976 20hp fit?
i've heard these motors are good, but some family members think i may be wasting my money on it. thanks again
Those 20's have lotsa pep and are great on a smaller boat. I think you'll be surprised at the performance once you get 'er going. After all, she's 1/2 of a Classic 50/40, one of the best motors Merc ever built (besides the Tower of Power Inline Six!).
On the carb kit, unless it's hammered all you'll need is the fuel pump diaphragm renew kit, a needle/seat assy if you think it needs it, and maybe a 'carb packing' kit. All of the 'hard' parts, jets, emulsion tubes, etc can be re-used. The carb packing kit contains a carb gasket and the various little gaskets, fiber washers, etc you'll need when you reassemble.
My Sierra parts book shows an 18-2007 carb gasket kit which looks like it has every gasket in/out of the carb including the ones for the fuel pump, minus the diaphragm. I'd recommend replacing the diaphragm also, it's getting on in years and with the ethanol-laden fuels will likely be eaten up in short order. I'd expect that the newer materials are more ethanol-resistant.
The book shows the above kit as a replacement for OEM P/N's 1399-5135 and 1399-5198.
P/N for the carb float, if you need one, is SIE 18-7209, OEM P/N 1395-9293.
The iBoats store carries Sierra parts, if you can't find them here, try
www.boatfix.com
HTH & Have Fun...............ed