I have run my boat around for several years with a M25C2, broke the bevel gear. Found a NS25C3 for $425 that sat for years in a garage changed the lower unit oil killed the spiders and cleaned it up. I put it in water and to my joy it started on the second crank. Ran great on the boat wot but idle was rough. I cleaned the carb changed the jet, float and valve removed the restrictor plate, timing was already at 25 deg btdc at wot about 2 deg atdc at idle and it idled great for about ten minutes. I have ordered OEM fuel line for the engine and fuel line from tank to engine and a new upgraded fuel filter. I don't like the wire clips thinking about going to ss marine smooth clamps. Any reason not to use quality marine clamps on the fuel lines instead of wire clips? Timing M30A4 is closer to M25C3. Thoughts and advise are welcome I like the old two strokes as I can't afford new stuff and operate in a shallow rocky river (Sacramento) for the most part.
25C2 BTDC 20° 4800 - 5500 ATDC 2° 900
25C3 BTDC 25° 5000 - 6000 ATDC 4° 900
30A3 BTDC 25° 4800 - 5500 ATDC 2° 900
30A4 BTDC 25° 5150 - 5850 ATDC 4° 900
25C2 BTDC 20° 4800 - 5500 ATDC 2° 900
25C3 BTDC 25° 5000 - 6000 ATDC 4° 900
30A3 BTDC 25° 4800 - 5500 ATDC 2° 900
30A4 BTDC 25° 5150 - 5850 ATDC 4° 900