25 hp Power Pack?

laujok

Seaman Apprentice
Joined
Sep 9, 2011
Messages
48
I think I'm having multiple issues with my motor (2000 25hp Johnson). Like I mentioned in my previous posts this motor just won't run properly. I took the lower end of today and it is full of oily grey sludge. I have checked spark few times with a spark tester and 7/16" gap and spark is bright blue on both cylinders. Compression is about 110 psi on both cylinders. Carb is rebuild and clean. Fuel pump is also checked.
I was wondering that is it possible that the power pack is giving low voltage or somehow giving random spark so that it is preventing proper firing and causing the grey sludge to form? I checked the coils for resistance and both gave 0.1 ohm on primary and 245 ohms on secondary side. I have also tried a pack from another motor and it didn't change anything. But when I tried my other motor (88' 20hp Evinrude) with these packs it had same kind of idle problem! And that motor ran great last year. So something very weird is going on...

Any thoughts?
Thanks
 
Last edited:

WA-Newb

Petty Officer 1st Class
Joined
May 27, 2012
Messages
238
Re: 25 hp Power Pack?

The grey sludge is water in your gear case. There are several seals that can go bad and dry out etc. You will need to do a vacuum test and pressure test to find the bad seal (I have no clue how so you will need to search this site).

The motor not running properly is most likely beyond my help but I did just find a bad wire on mine that caused my motor to perform very poorly and cut out. It was the power supply to my power pack.
I couldn't see the wire was bad but did see a little bubbling on the casing of the wire.

I started a thread just now showing the wire and a video of before and after the wire was fixed:
http://forums.iboats.com/showthread.php?t=560580

Also there is an inline spark tester you can get that you hook up to your spark plug wires (or coil) to check for good spark.
This may help you out and I think you can probably make one as well...again search for checking spark, or spark test.

I am totally new to boats so don't take my word for anything though...just trying to give some input for once instead of asking for help...lol

Good luck
 

AlTn

Commander
Joined
Mar 9, 2010
Messages
2,813
Re: 25 hp Power Pack?

I think you've answered your own question if these packs cause the same symptoms on a known to be good engine. With the lower unit off, examine the inner exhaust housing.Is this gray sludge film on the walls? It may be easier to examine with the engine resting on the flywheel with the exhaust housing pointed up.
 

laujok

Seaman Apprentice
Joined
Sep 9, 2011
Messages
48
Re: 25 hp Power Pack?

Yes, the whole lower unit is full of grey sludge. I took exhaust cover off and there was some not much sludge in the baffle plate, so much that it was slippery. I also pulled the head and there was this sludge on the head too + lower part of the crank case (intake) was covered with black juice. I had a little break on working on this motor and on Monday when I first started it ran like a dream on idle (about 10 sec), but as soon as the water pump lifted the water up to the block it started running badly and smoking. I've done both cyl head gasket and exhaust gaskets. I have sanded both surfaces too (exhaust and head). Where could the water get inside the block? I have only had it running in a barrel this year so far..
 

Haffiman

Commander
Joined
Dec 17, 2009
Messages
2,454
Re: 25 hp Power Pack?

'Where could the water get inside the block?'
You may have to make some sealing plates and pressure test the cooling circuit.
Remove the thermostat cover and plug the thermostat hole.
Leave the block on the mid section and attach a water hose straight onto the water tube.
Remove spark plugs and intake/reed-plate and apply pressure.
If lucky you may get an idea where it is coming from.
 
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