Starter Current Draw - 99 Johnson 150HP

[Makaboy98]

I have a 1999 Johnson 150HP OB with carbs. I know that these starters require a lot of current to turn them so strong batteries are needed. The factory manual calls for 30A during a no load starter motor test at a specific RPM. Which I'm getting during this test, 30-33A measued with an inductive clamp amp meter. However, like any other electric motor there is the initial inrush of current when you first apply power to it, so does anyone know what that inrush is suppose to be? I'm getting around 550A on my starter, which seems excessive for a starter that only pulls 30A running current. I'm concerned that this may starter going bad but I don't want to buy a new starter and find out that it pull the same amount. The starter on my V6 truck only pulls about 4 times the load current during the starter inrush (765A/160A) but this OB is pulling almost 18 time the load current (550A/30A).

Does anyone have that info?

Thanks

 

[rickdb1boat]

Re: Starter Current Draw - 99 Johnson 150HP

I don't have that particular engine info, but 550 Amps. is high and I believe that 200-300 would be more like it. I know the manual for my 90 HP calls for 65 Amps (No Load) and 200 amps under load. Hope this helps..

 

[angus63]

Re: Starter Current Draw - 99 Johnson 150HP

Two things to keep in mind....
One, your truck is only overcoming half the cylinders in compression stroke each revolution since it is a 4-stroke
Two, your truck uses the battery for ignition current, while your outboard has to spin fast enough to generate it's own current for ignition. That's why a 650 cranking amp minimum battery is recommended for the outboard. The v6 starter turns 10,500 rpm under no load. The v4 starters only turn 6500 rpm. I would expect the inrush to be pretty high relative to your truck and a v4 starter.
Good luck

 

[Makaboy98]

Re: Starter Current Draw - 99 Johnson 150HP

Thanks for you input. Some additional info, the starter draws about 150A under load, therefore when turning the engine over with the sparkplug wires disconnected.

If anyone installs a new starter and can perform a no load starter test, I would be interested to know what initial maximum inrush current is on a new starter.

Thanks

 

[JustJason]

Re: Starter Current Draw - 99 Johnson 150HP

did one the other day, the inrush on any starter is typically double its nominal... so in your case 300A would sound about right. But that's only for a couple of miliseconds. It should settle right down to 150A. If it doesn't, and you have a new starter, check all your cables, connections and solenoid. Also.. it should be 150 with the plugs in, not plugs out.

 

[Texasmark]

Re: Starter Current Draw - 99 Johnson 150HP

My '94 up 75 thru 125 hp (3/4 cyl engines) states 75 amps unloaded and 120/150 amps respectively loaded.

Mark