Speedo problem on 150's

[captaindarrell]

I have twin 150's on my boat - how can you tell which engine is feeding the speedometer? I have a clog and the mechanic is having a difficult time solving the issue. only getting about 30% of the known speed. Can the engines be swapped out by reconnecting a plug?

[bajakeith]

speedo

Hummm,, you use the word "mechanic" loosely..cause that guy sure aint!! One of the tubes from the motor will run up to the back of the guage...Very Important that he rehooks it up super duper or will come off and wipe out your wireing..something Ive seen Waaay too many times

[Sequoiha]

Normally the standard rotation engine is the speedo feed, there is a good chance the hole in front if the gear case is plugged up.

[TownsendsFJR1300]

Try a version of this, at least using air from the console, blowing down to the engine.

Look and feel for water/air coming out the leading edge of the LU;

http://www.yamahaoutboardparts.com/f...g-th23159.html

This set up will keep your speedometer working correctly indefinitely if done on a regular basis.. Mines 8 years old now (salt water use).

BTW, they'll be a black HOSE, a little larger than 1/4" traveling from one of the engines, with the rest of the wires. About a foot and a half from the engine, WILL BE a male to male hose connector. That's your speedometer hose...