Fuse on Tohatsu 8hp starter battery cable?

[caverun]

I've installed a Tohatsu 8hp electric start outboard on my H240 (same motor as the 9.8hp). My only battery has a Blue Sea terminal fuse block with 40 amp fuse for the boat circuits. After a few starts the outboard starter blew the 40A fuse. Does the battery cable from the outboard need to be fused at the battery, or should I just increase the fuse size to say 60A (8 gauge battery cables, 8 ft long)? The starter motor is rated at 500 watts, so I understand why the 40A fuse blew. I would prefer not to get a separate start and house battery on a boat this small.
Any advice on the best and safest way to do this is appreciated!

 

[twalker H260]

Based on owners manual it looks like the 8/9.9 hp use a 20amp fuse in the motor for the starter. You might want to check your cables and connections. Our Yamaha is similar.

 

[caverun]

Thanks, I think the 20A fuse (circled in blue on the diagram) protects the charging circuit- not the starting circuit- please correct me if I'm wrong- just wondering if I need to protect the battery cables with the fuse block on the positive terminal?

 

[twalker H260]

Fuse should be within 7” of battery terminal to protect wire. (And your boat in case of dead short etc) From blue seas it looks like you could fuse a single 8g wire at up to 80 amps. 60 should work.

http://assets.bluesea.com/files/resources/reference/20010.pdf

if Original fuse was/is also protecting other circuits you will need to look at the wire size for those circuits. Might need to use more than one fuse at positive terminal.