Slow Cranking?

[bustab]

Hi, I have a mid 90's inline 4 115 Merc. It cranks really slow. I changed the starter and solenoid, as well as tried a brand new battery even though I load tested the last one and it checked out fine. With the key off I got twelve volts on the battery side of the solenoid. when i put the voltmeter on the starter side of the solenoid and crank, the voltage drops to 4 then 8 and really just jumps around. I should be getting twelve volts at the starter no? i'm thinking the only think I have left to check is the battery cables or maybe a ground on the starter? It's starting to drive me a little nuts. I tried throwing a few parts at it before I did an actual tests which was kinda stupid. Now I'm a little stumped. Does anyone have any ideas I can look at? Any suggestions would be greatly appreciated.

 

[JB]

Re: Slow Cranking?

Where are you putting the ground lead from your meter when you measure the 4-8volts on the starter?

Put the ground lead on the negative terminal of the battery and do the voltage tests in "Outboard won't start" in Engine FAQs.

Let us know what you find.

Sounds like a bad starter at first, but you gotta do the verifying. One possibility not covered in the troubleshooting is a bad connection from the starter frame to the engine block.

 

[bustab]

Re: Slow Cranking?

I was putting it on the ground side of the starter. I'll go through it tomorrow and connect my meter to battery ground. I'm sure the voltage will be below normal. I'm thinking I got corrosion between my starter and block ground. Thanks for the reply.

 

[bustab]

Re: Slow Cranking?

ok so i'm getting 12.27 volts from the positive to negative battery terminal (non cranking) when i crank it drops to 9.87.

then the negative bat terminal to the solenoid cranking i get 8.43.

negative bat terminal to the starter side of the solenoid 8 volts and it just keeps going down from there.

i cleaned all the grounds on the starter and where the starter connects to the block.

i disconnected the bat cables from the battery and used jumper cables to the the starter still no start.

a few times when i started playing with it today id crank it and it would take a few rotations to get going then it would spin fine. but would feel like it's lagging when i first turn the key.

It has to be another bad starter no? theses start systems arn't that complicated. what else could it be?

even if it is a bad starter shouldn't i be getting close to twelve volts at the starter? thanks!

 

[JB]

Re: Slow Cranking?

If the battery voltage drops to under 10v while cranking there seems to be enough current flowing to operate the starter motor, but voltage at the solenoid and starter should be higher and battery voltage should drop lower.

There is an almost 2v drop from the battery + to the solenoid input. That is too much. I am suspicious of the + battery cable and its connections to the battery and the solenoid. Check that carefully for internal corrosion and clean the connections.

I am also suspicious of the starter motor because it cranked slow when you put the battery to it directly.

However. . . If it intermittently cranks fine that points to a bad connection that it heating up and either getting worse or better.

Do you still have the original starter? If so, put that back in and retest. Sometimes changing parts adds problems.

 

[jimg984]

Re: Slow Cranking?

need large batgtery with high cranking amps

 

[jimg984]

Re: Slow Cranking?

also a deep cycle (trolling battery) has a slow current flow thru it due to thick lead plates, that makes for slow cranking

 

[Chris1956]

Re: Slow Cranking?

Busta, It sounds like the battery cables have corrosion on the terminals or perhaps on the cable itself. Look for a bulge in the cable. That will be the bad spot.

 

[hkeiner]

Re: Slow Cranking?

The below linked thread contains a starter troubleshooting guide. You may find it helpful.


http://forums.iboats.com/showthread.php?t=224094&highlight=starter

 

[bustab]

Re: Slow Cranking?

thanks everyone for your replys...i'll get back at it tomorow. workin overtime i'm beat.

i put the old starter back on yesterday, and the same old thing...starer cranking slow.

i'm going to rip the starter apart tomorrow and snoop around. The one i got was used so i am prepared to buy a brand new one if this doesn't work. might just be stuck brushes or dirty inside. the boat did sit for 14 months without any love. i don't know if i mentioned that.

thanks again

 

[bustab]

Re: Slow Cranking?/Fuel probrem now!

Re: Slow Cranking?/Fuel probrem now!

Twas the starter...two bad ones one good one...

Now she fires up after priming, then just dies after 10 seconds. Runs outa fuel. Can't keep it going with the primer bulb either. won't start back up again without priming. changed the inline fuel filter not because I thought it was the problem just did it because i had a new one.

I took the carbs off before the season to clean...sprayed powertune through all ports. (98% sure I put them back together properly)

The fuel I'm using is pretty old but had stable in it...I'm going to hook up a remote tank tomorrow to eliminate the boat as the problem. Although I'm sure it's not. I just want to run brand new gas through it.

When I prime the bulb the inline filter doesn't fill right up either. Normal?

Thats all I really got today I had to stop and had to spend "quality time" with the girlfriend.

As I'm writing this I'm thinkin I have to take the carbs back off to make sure they are together properly. Someone please write back and tell me it's something else so I don't have to.

 

[jimg984]

Re: Slow Cranking?

have you tried disconecting the fuel line between carbs and fuel pump and cranking engine over to see if fuel pump is working

 

[bustab]

Re: Slow Cranking?

fuel pump was fine...it was a stuck needle in the top carb. no fuel getting in the bowl.

new problem though. I think it's flooding

I prime it up...fires fine runs for a bit then stalls out. took the plugs out and they are soaked and clean...i set the idle to the initial setting. it just doesn't want to stay running. it's also blowing lots of black oil out the mid section. (I took off the gearcase so I didn't have to worry about the water pump). the battery just died so i got it on a charge now. One thing after another with this thing right now