3.0 johnson cranking RPM

**Gorilla0178** · 09-30-2019, 03:51 PM

Is there a way to test the cranking rpm of a starter? My motor is always hard to start. Even on a fully charged battery. It doesn't sound like its spinning as fast as another motor we have. The other motor is a xp150 evinude. The Rude sounds crisp and zippy when it starts up, and it starts no prob. Mine sounds like its spinning slower. I know it needs a certain amount of RPM to make good spark. It does have spark, ive tested it. But still leaves me wondering if itll start when I want it to. When it starts it runs good, and will start every time after. Its just the cold start that is iffy. Or anything else I might be over looking?

**XstreamVking** · 09-30-2019, 06:14 PM

Check the timing.....

**Gorilla0178** · 09-30-2019, 08:01 PM

Ok. Thats easy. I'll check that next time I have a chance.

**Motv18** · 10-02-2019, 11:55 AM

Spark lead clamp rpm meter. Just need a tach hooked up.

Spark lead clamp lamp is just handy in the shop clip crank done.

**Instigator** · 10-02-2019, 08:58 PM

Common prob on them.

Ck all cables from battery to starter.
if nothing there, it may be the starter.

The brushes ride on top of the armature, just below the bendix.
A common issue is people over oiling the bendix, oil runs down and through dust shield and to top of armature.
That insulates the brushes from the armature and eats the batteries amperage.

Normally you can disassemble, clean, reuse everything and double the cranking speed.
If it needs brushes, Pro Marine has them.

Ive had loopers fail ignition cranking tests, clean up the starter, change nothing else and it passes.

Goid luck!

**Gorilla0178** · 10-05-2019, 04:50 PM

Originally Posted by Instigator

Common prob on them.

Ck all cables from battery to starter.
if nothing there, it may be the starter.

The brushes ride on top of the armature, just below the bendix.
A common issue is people over oiling the bendix, oil runs down and through dust shield and to top of armature.
That insulates the brushes from the armature and eats the batteries amperage.

Normally you can disassemble, clean, reuse everything and double the cranking speed.
If it needs brushes, Pro Marine has them.

Ive had loopers fail ignition cranking tests, clean up the starter, change nothing else and it passes.

Goid luck!

It's been an issue ever since I've had it. I got rid of it for a while and got it back. Different block tbough. The other guy blew it up a couple times when he swapped from 200 to 225 carbs. Fuel restriction on cyl 1. Monty worked it out, so I was told. Has CCMS reeds. I dont recall the comp test numbers off hand. I did one awhile ago, they were all good. I haven't oiled the starter so not sure that's an issue. Not a new issue. Just it's thing. And compared to the xp150 we have, mine cranks slow I think. Even on full charge and jump box connected.

**H2OPERF** · 10-06-2019, 09:14 AM

The xp is a direct drive starter the looper is a geared down starter they don't sound the same. Check the brushes like Gary said if ones stuck or worn out it will run slow but still turn it over.. sounds like its been around for a while. check spark with all sparkplugs in and check all cylinders with a spark tester not plugs hanging on the heads u cant see all the cylinders at one time, everyone pulls the plugs and it will turn way faster..

**Nitro25** · 10-11-2019, 05:30 PM

Used to be 300 RPM minimum. I use this handy guy.

D.

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**Gorilla0178** · 11-08-2019, 07:10 PM

Ok bringing this back up. Haven't had a chance to check anything, but I charged up the battery and tried to start it today, No luck. It seemed to be spinning fast enough, but I'll still look into the starter. I started it a couple weeks ago after a couple tries but it was iffy. So after a couple tries today I checked spark. Nope, no spark on any cyl. Kill switch lanyard was in, that's as far as I got. Can anything go bad without running the boat? I changed the plugs a couple months ago and it started right up, last time I tried it took a couple tries this time no luck. I haven't even taken It out in months. Where should I start first, if it's not cranking rpm?

**Motv18** · 11-08-2019, 09:08 PM

Pump up the bulb good and hard. Check the fuel lever thing if it has it.

Did you unplug anything when stored.

Not running it it would take a critter or such or corrosion for something to go bad. But it can fry just as you turn the key off the last time.

**Merc 2.5** · 11-08-2019, 10:02 PM

Agree with motv. It could had happen when turned off or on last time. The power packs been known kinda just (go out)
Merc kinda does same. Run fine in fall. missin in spring. Just gonna have to go thru normal diagnostics

**Gorilla0178** · 11-09-2019, 07:23 AM

I'll have to look at it some more. As far as fuel and the lever, that's all good. Has a electric fuel pump and I double checked lever.

**Capt.Insane-o** · 11-09-2019, 08:53 AM

360 rpm is the spec called for. The stock battery cables are inadequate for these motors and the gear reduction starters leave some to be desired.. especially for the v8.

**Gorilla0178** · 11-09-2019, 12:00 PM

What size should they be? I'm not sure what gauge they are but about 1/2 inch in diameter. They've always been with the motor. I'm gonna clean all the connections and check them. If it is a progressive issue maybe it's corrosion. Im gonna get a handheld tach and check the cranking rpm too.

**Gorilla0178** · 11-09-2019, 06:15 PM

Ok. I went over and checked the wire size and it's 4 gauge. The battery is pretty much fully charged. I cleaned all the battery and battery switch connections, all the connections on the motor are clean. I put a piece of tape on the flywheel and cranked it over, it's not spinning fast enough. I set a timer and counted the tape rotations and it's only 12-13 revolutions per 5 seconds. Which is only about 150 rpm. So I think the starter needs service or replacement. Any thoughts?