Tohatsu 9.9 & 15 Timming
Tohatsu 9.9 & 15 Timming
Apart from changing old to new advance cam, there are some adjusting timming differences. Don't know how old is your current 9.9 model version, it it were a 9.9 D and wanted to update to a 15 D, both timmings are same, 22? a perfect match; if it were a 9.9 D2 and updating to a 15 D2, there is a 5? timming difference, first has 20?, second has 25?, will need to adjust upper stopper bolt CCW untill tiller & timming mark has advanced + 5? to stop at 25? mark. Tighten stopper bolt nut on that position.
Adjust rod height by means of upper screw, throttle arm rod should be at wot when tiller has reached max acceleration & timming mark has stopped at 25?. There should be no under pressure, just a very slight over pressure of roller against cam, that's why need to adjust if required. The butterfly must be at 180? (wot) when at full tiller end.
This issue may apply or not to your engine, check model and adjust if neded. The same advance + 5? timming applies + carb gasket change when modifying a 25 C-3 to 30 A4.
Happy Boating