need help electric start Honda 7.5HP

Marcel El Koubi

Recruit
Joined
Sep 27, 2009
Messages
3
I was given a 7.5 with electric start BUT the battery cable was cut off and all I have are 2 red leads coming off where they attach to motor.
Looking down on the spot where it attaches there are two phillips head screws, I would like to know where + and - attach ie: + plus on the right screw or is it the left one? Thanks:)
 

cp

Petty Officer 1st Class
Joined
Feb 1, 2004
Messages
367
Re: need help electric start Honda 7.5HP

It seems Honda did not sell an electric start 7.5HP outboard in the USA, which may explain your inquiry not receiving any replies.

That being said, there are standard ways to configure an electric starting motor and that should enable you to determine which polarity to connect where. You will have to do some tracing of wires and a multimeter will be most useful. If you are not competent in use of a multimeter, or do not have one, perhaps it would be best to take the motor to a service shop. An alternative would be to rig up a flashlight bulb with a couple of 1.5volt batteries to use to trace wires (if you have no idea how to do that, then you should have a knowledgeable service technician determine the polarity for you).

If you do wish to try determining which wire is what, you must first look very closely at the two cut off wires. Do they actually go to the starting motor or are they actually connected to a starting relay? It is standard for starting motors to be fed the 12volt power from the battery through a starting relay, not directly from the battery. Also, the actual starting motor usually only has one wire (the positive) going to it, the casing being the return or negative conductor. For those reasons it is likely that the two wires you refer to are actually connected to a starting relay rather than to the starting motor itself.

A starting relay usually has four connections. One goes to the starting motor and this usually is a larger wire, or a direct internal connection (in which case you might see only three connections). One is the input from the battery and this is also usually a larger wire (but may not be given the small size of your outboard, meaning the starter motor may also be small/requiring less current). If you can in fact identify one or two larger wires, then your task is considerably simpler for you will have eliminated having to determine what one or two of the connections at the starting relay are used for.

For the rest of this discussion, let's presume that you have isolated the two larger leads. That leaves two more connections at the starting relay. These will be for energizing the relay coil. You can verify that by measuring continuity (but not zero ohms) between the two. Trace the two wires and you should find that one of them ties to the electric starter switch. That one is most likely the positive. The other wire may show continuity to ground/negative but it may not depending on internal connections in your rectifier/voltage regulator.

Hope this helps; let us know if it did or not. Good luck.
 

ngt

Master Chief Petty Officer
Joined
Feb 26, 2009
Messages
874
Re: need help electric start Honda 7.5HP

i wish my honda 7.5 had an electric start :(
 
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