Honda 75 goes up and down like a -yoyo

[donmackay 7777]

My newly acquired used Honda 75 4-stroke is playing tricks on me. It is a 1999 BF75A model. I left the boat on its trailer with the engine in the fully down position, and next time I saw it the engine was in the fully up position, and the battery is drained flat. I do not think anyone tampered with it. I suspect salt water corrosion in the engine up/down switch Is this the most likely cause? Is the switch easily removed / replaced? Thanks....Don

[Tim M]

This happened to me last year on a Mariner 40 that I had (it was a 98 model). Half way accross Portsmouth harbour the engine started trimming up and out of the water. It was the wiring inside the control box; wear from moving the throttle back and forth and damaged the wires that went to the ptt button on the end of the throttle. On the mariner it was simple to just disconnect these wires under the engine hood. There was a seperate button on the engine casing to raise and lower the engine which worked fine until I replaced the wiring in the box. Might be worth trying to dissconnect the control box button for a while and see if it carries on happing. If it does maybe try doing the same for the button on the engine (if there is one).

[TimMcC]

Originally Posted by donmackay 7777

My newly acquired used Honda 75 4-stroke is playing tricks on me. It is a 1999 BF75A model. I left the boat on its trailer with the engine in the fully down position, and next time I saw it the engine was in the fully up position, and the battery is drained flat. I do not think anyone tampered with it. I suspect salt water corrosion in the engine up/down switch Is this the most likely cause? Is the switch easily removed / replaced? Thanks....Don

Hi

Happened to me twice . Once due to a faulty switch in the control box causing the motor to trim out while in the water and once while the boat was on its trailer the trim switch on the outboard went faulty causing the outboard to trim in while the mechanical latch was in place Both times it was Mariner 60 .

Tim

[martx007]

Don
I also have the Clymer Marine Maintenance And Repair Manual for Honda outboards to 2006. If you get desperate, and you don't have it already I can scan in relevant pages if you need to work on any section of it.

Martin

[donmackay 7777]

Originally Posted by Tim M

This happened to me last year on a Mariner 40 that I had (it was a 98 model). Half way accross Portsmouth harbour the engine started trimming up and out of the water. It was the wiring inside the control box; wear from moving the throttle back and forth and damaged the wires that went to the ptt button on the end of the throttle. On the mariner it was simple to just disconnect these wires under the engine hood. There was a seperate button on the engine casing to raise and lower the engine which worked fine until I replaced the wiring in the box. Might be worth trying to dissconnect the control box button for a while and see if it carries on happing. If it does maybe try doing the same for the button on the engine (if there is one).

Hi Tim....a logical approach which makes good sense...thanks

[donmackay 7777]

Originally Posted by TimMcC

Hi

Happened to me twice . Once due to a faulty switch in the control box causing the motor to trim out while in the water and once while the boat was on its trailer the trim switch on the outboard went faulty causing the outboard to trim in while the mechanical latch was in place Both times it was Mariner 60 .

Tim

Hi Tim....could be either the control box or engine switch then, thanks...Don

[donmackay 7777]

Originally Posted by martx007

Don
I also have the Clymer Marine Maintenance And Repair Manual for Honda outboards to 2006. If you get desperate, and you don't have it already I can scan in relevant pages if you need to work on any section of it.

Martin

Hi Martin, I do not have the Clymer manual. You kind offer is most welcome. Would you mind scanning in the pages relating to the engine up/down switch and the control box unit, and email them to me at donmackay@tiscali.co.uk .....many thanks...Don

[martx007]

ok will do at the weekend

Martin