where"s the boss

[bobjoe1]

I have a 1989 EvinrudeE40TLCEC and would like to be able to find the correct tapped boss to install a temp sending unit. I found one right to the left of the upper cylinder spark plug but it is tapped 3/8 inch. I am being told by teleflex that the correct boss would be 1/8 inch the same as that of the sending unit. Help

 

[F_R]

Re: where"s the boss

I have no idea if that is the correct hole or not, but a 3/8" SAE thread and a 1/8" NPT thread "look" almost the same--but are different. The SAE is a straight thread and a 1/8" NPT is a tapered thread with a slightly different threads-per-inch count. BTW, 1/8 refers to the nominal inside diameter of a threaded pipe that would fit the hole, and 3/8" refers to the outside diameter of a bolt that would fit the hole.

But you may already know all this. Somebody else out there may not.