2001 Merc Optimax 135 Battery Cables

Hi Folks,

I`ve been a member on here for sometime now mainly in the Honda section but decided to have a change for my current renovation project so have got myself a 2001 merc 135 optimax salt water extra long shaft.

When the outboard arrived then it wasn`t supplied with battery cables so I`ll need to replace them but I`m not sure what # AWG rating they should be as I understand that the optimax requires a steady current when starting. I was thinking maybe #2AWG which are 35mm2 but I`m not sure if these will be too thick to go through the outlet from the bottom cowl as I also wasn`t given the inserts either.

Cheers for any help in regards to this.

Matt

Well after much searching about then I`m now able to answer this myself. I thought I`d post up what I found in case anyone is interested.

DFI (optimax) 115hp to 175 hp outboards

Cables upto 12ft (standard length) the cable size needs to be #4 AWG

Cables from 13ft to 21ft need to be #2 AWG and 22ft to 24ft need to be #0 AWG

thanks matt.speedtriple

Install the largest cable you can fit, no matter what the distance. Optimax engines like a large battery (1000 cranking amps) and do not like voltage drop.

I concur bigger is better,less resistance,more current flow, basically no voltage drop from battery to starter. "OHMS LAW"

Cheers guys but I posted this question up to find out what merc fitted and supplied with the optimax as standard.

I've been a bike mechanic for over 30yrs plus done a fully engineering apprenticeship as an electrical mechanical service engineer. I've also been working on both outboard and inboard engines throughout that time gas and diesel so have an idea of what the difference between a left and right handed spanner is by now.

The engines did not come with a rigging power supply cable. The last two I rigged didn't have any.