whats the AMP draw when starting a 1997 Johnson Fast Strike 175 hp outboard

[bob johnson]

I am looking to size the battery cables... I have to run about 20 feet of cable..... does the ground wire have to be as big as the power cable? I know lots of guys say JUST GO BIG!!!, and I did that on my last boat that is running a 115 ocean runner. and guess what.... there isn't much room to run oversize cables into and through that power head!!...it is tight in there, and I had a bear of a time snaking the larger cables through the entry way into the motor and down the side of the block to the starter!!!!!!!!!!!!...so I want to run what I need and not much more


bob

 

[bob johnson]

OK, I found it.... how do you delete a post these days??? we used to be able to go advanced edit as well...and I don't see that option any more

bob

 

[GA_Boater]

Why not post what you found instead of trying to delete the thread. It might help someone in the future.

So - What is the starting current for '97 Johnson 175 Fast Strike?

 

[bob johnson]

I'll trade ya..... tell me how to delete a thread I started and Ill give the info!!!!!

because sometimes it is prudent to remove your own thread!!!

the into I received didn't offer an amp load.....it offered tha min size battery cable required for various lengths. Which is why I was asking for the amp draw in the first place....to size my cable!!

the book says that for16- 20 ft id need 1 guage wire. for 11-15ft Id need 2 gauge, and for 1-10 ft, Id need 4 guage


BOB

 

[Vic.S]

I'll trade ya..... tell me how to delete a thread I started and Ill give the info!!!!!

because sometimes it is prudent to remove your own thread!!!

the into I received didn't offer an amp load.....it offered tha min size battery cable required for various lengths. Which is why I was asking for the amp draw in the first place....to size my cable!!

the book says that for16- 20 ft id need 1 guage wire. for 11-15ft Id need 2 gauge, and for 1-10 ft, Id need 4 guage


BOB

Answering one point in your original post: Yes the negative and positive cables must be the same size!

Be aware that very often tables of cable size vs current and cable length are based on the total positive plus negative lengths.
This would mean that if it is a 20ft cable run to your engine that is a total length positive + negative of 40 ft. many calculators and tables would require you to input this rather than 20ft.
Be sure you know if the book you have consulted uses this basis or not.



ITYWF that the only way to delete a post is to ask Admin to delete it for you.
For a short while ( 1 day??) you can edit a post which means you can delete all the text and just leave a note to say "post deleted" or something similar.

 

[bob johnson]

Answering one point in your original post: Yes the negative and positive cables must be the same size!

Be aware that very often tables of cable size vs current and cable length are based on the total positive plus negative lengths.
This would mean that if it is a 20ft cable run to your engine that is a total length positive + negative of 40 ft. many calculators and tables would require you to input this rather than 20ft.
Be sure you know if the book you have consulted uses this basis or not.



ITYWF that the only way to delete a post is to ask Admin to delete it for you.
For a short while ( 1 day??) you can edit a post which means you can delete all the text and just leave a note to say "post deleted" or something similar.

looks like its just the ONE way:

bob

 

[GA_Boater]

You have 1 hour to edit a post.

 

[Vic.S]

looks like its just the ONE way:

bob

That seems clear enough, 1 AWG it is then.

Looks like they are catering for about 120 amps.

So you only get an hour to edit a post . . . . . . . . . :blue:

 

[bob johnson]

That seems clear enough, 1 AWG it is then.

Looks like they are catering for about 120 amps.

So you only get an hour to edit a post . . . . . . . . . :blue:

I think the 1 guage will be hard pressed to get through the opening into the motor and along the side of the motor....it is feasible to run the thick stuff to the stern and then run maybe a 4 guage from a battery switch at the stern into the motor????

Ill have the batteries up front under my seat... but I want to avoid trying to feed that monster thick cable through the harness opening on the cowl and along the side of the motor and not interfere with the motor cover going back on!!!

bob

 

[Vic.S]

I think the 1 guage will be hard pressed to get through the opening into the motor and along the side of the motor....it is feasible to run the thick stuff to the stern and then run maybe a 4 guage from a battery switch at the stern into the motor????

Ill have the batteries up front under my seat... but I want to avoid trying to feed that monster thick cable through the harness opening on the cowl and along the side of the motor and not interfere with the motor cover going back on!!!

bob

You could do something like that but presumably you already have a battery isolation switch close to the battery so not really necessary to add another, just a suitable junction box at the stern.

Remember though that 4 awg cable has twice the resistance of 1 awg. (0.8 ohms/1000m compared with 0.4 ohms/1000m) It might be worth running from the battery to the stern in 0 awg then to the motor in 4 awg.

 

[jakedaawg]

Just out of curiosity....What type of vessel is this that the batteries need to be 20' from the motor?

 

[bob johnson]

Just out of curiosity....What type of vessel is this that the batteries need to be 20' from the motor?

its a starcraft..., they don't HAVE TO BE 20 feet from the motor, I want them to be! I want to balance out the boat. I want to avoid having the stern so heavy.... so the boat sits low in the back in the water... its 22 feet but aluminum, so it is not heavy.... motors , gasoline and batteries, make the rear heavy!!

and its about 20 feet on cable...not 20' of direct line distance!!! this boat will be used in rough seas in winter... and I don't want my batteries in the rear....

bob

 

[Crosbyman]

well.... have you considered storing the fuel in front and leaving the battery in the rear with smaller wires

it is probably easier to snake a fuel hose front to rear versus snaking 2 fat expensive cables to the back of the boat


btw maybe you can split the amp load on 2 smaller wires ( easier to snake one each side of the boat and rejoin them in the back ..

. each will carry 50% of the needed amps

 

[bob johnson]

traversing the boat isn't the issue, its getting through the opening where all the wires go into the motor. and then down the side of the motor to the starter...its TIGHT!

bob