1986 SUPER SPORT 15 1986 Johnson 70-HP

[JohnRowlette]

My 1985 SUPER SPORT 15 [with a 1986 Johnson 70-HP engine] can reach a boat speed of 44 at full throttle and[ appropriate engine] trim.

I am still using [a propeller described only in the most vague terms as ] "a stock propeller." The propeller is full of nicks, and I was still able to reach a boat speed of 44. I took out all the nicks and sharpened [the blades] with a files, so maybe [now the boat speed will increase to] 45.

BACKSTORY
I had frustrating problems with my 1986 Johnson 70-HP two-stroke-power-cycle engine. The engine produced an unbelievable amount of smoke. The engine was prone to stalling all the time. I thought this engine was was on its last leg. However, a mechanic took one look at it, and put in a new fuel hose from the tank to the engine. That [cured the excessive smoke and tendency to stall]. The mechanic told me [rubber hoses with a black outer appearance] were not the best quality, and he installed a new hose with a gray outer appearance.

[jimh]

The mechanic told me [rubber hoses with a black outer appearance] were not the best quality, and he installed a new hose with a gray outer appearance.

That comment seems completely out of touch with what most people have experienced. Fuel hoses with a shiny, metallic gray outer jacket are widely know as defective, and typically the inner lining of the hose will collapse, resulting in severe fuel flow restriction.

[jimh]

I am still using [a propeller described only in the most vague terms as ] "a stock propeller."

In reporting information about the performance of your boat, the information will be much more useful if you provide details about the propeller being used, including the brand, the model, the material, the number of blades, the diameter, and the pitch.

When reporting performance information at full-throttle, the inclusion of the engine speed in RPM will make the data much more useful.

When reporting boat speed, please indicate the units of measurement and the the device used to measure the velocity. Because small Boston Whaler boats do not typically make long ocean voyages in which they are out of sight of land for weeks and weeks and navigate by deduced reckoning using the relationship that one-minute of latitude is one nautical mile, the best unit to use is statute-miles-per-hour, which is indicated by the acronym MPH.