[Storm27m]

Here's another question about lower unit leaks. I did a search of this forum and it didn't really answer my question. I'm guessing I may have a bad seal on the prop shaft? I know very little about outboards, but I do have a manual on the way. Unfortunately, it didn't make it in todays mail. Anyways, here is the description and a few pictures.

Background: Motor is a 1993 Evinrude 30hp tiller, electric start. I bought this motor on a jon boat in Feb, ran it briefly (in barrel) before purchase, didn't notice anything, but it was dark out. I've had it running at home once (in barrel) and didn't notice anything.

Today was maintenance day and part of that was changing the lower unit lube. Lube looked very good, almost new, but had the (normal?) smell I've read about. I also changed the screw seals. After changing the lube, I ran the engine a bit (with bunny ears) It took a few good cranks to get it running (electric start), but ran fine once it was going. Then I noticed the milky froth coming out from the prop area. Putting it on my fingers, it was very frothy but only had a slightly oily feel to it. It was much lighter/frothier than I expected by looking at it. I should probably add that there have been no visible leaks on the ground under where the motor is stored (Boat/motor stored in garage)

For all I know, this could just be crap coming from the exhaust but with my luck, I'll assume worst case until it's proven otherwise! If it is a leak in the lower unit, I'd have to assume that the old owner pulled one over on me and tried to hide this (nearly new looking lube):angry:. I hate to think that, but I know how some people are. Any advice on what needs to be done, special tools involved, and parts needed would be greatly appreciated. Here are the pictures. Thanks.

http://farm3.static.flickr.com/2326/2443109333_1ec3ca1013_b.jpg

http://farm4.static.flickr.com/3090/2443935082_1907d972bc_o.jpg

 

[AwShucks]

I would venture to say the seals inside the hub are either shot or non-existant. First time I've seen one leak like this though.

 

[Bubbakat]

That could also be unburned fuel from where the motor not getting up to the righ operating temps. IE like missing t stat or running at idle for a long time. I would make sure the lower unit was full and take it to the water and run it under a load to see if it has water intrusion and to bring that motor up to operating specs.

 

[Storm27m]

Thanks for the advice. If the weather holds out, I'll try to get out tomorrow and see what happens. I just refilled the lower with fresh lube, so I should be good there.

 

[Bobpaul]

Run it again in the barrel. Pull off one plug wire at a time, and be sure you're hitting on both cyl's.

You'll need well insulated pliers to do this

 

[Storm27m]

Thanks Bobpaul, another thing to look into.

 

[Storm27m]

I had the engine running again this morning an I'm pretty sure it is unburnt fuel. I didn't think to smell it yesterday, but it does smell like gas. After I ran it a bit, the sludge went away. I'll still double check the lower unit after I've had it in the water a bit.

I did check the cylinders as Bobpaul suggested and both were firing. I did notice a misfire every so often at idle and higher RPM's. Other than that, everything seemed fine. Any suggestions on what to look at now regarding the misfire? Thanks again.

 

[Bobpaul]

Run it in the dark with the hood off. Look for a spark leak(Arching to ground)

 

[Bubbakat]

Good suggestion bobpaul good minds think alike :wink:
If the arc ain't visible then take each coil off and look for cracks on the under side of them and a croded graound wire from the coil will make one miss also.

 

[Storm27m]

OK, let me see if I got this. I need to run the engine in the dark with the cover off. I need to look for an ark leaking from the plug area to the motor itself (with the plug wires on). If I don't see any arc, then I need to look at the coils and the ground wire from the coils.

Thanks again for the advice.

 

[Bobpaul]

I've also ran it in the daylight and lightly spayed the engine with water. That'll show you any ignition leaks also.

could be that you just need to run it.

A plug could have a cracked insulator.

There's a few other variables also. It's kinda like giving someone a hair cut over the internet.:wink:

 

[Storm27m]

Well, you've certainly given me plenty of places to start looking and I appreciate that. If I can't get it resolved, I'll try to post a video or something. In the meantime, you guys have given me plenty stuff to check out. Thanks again.

 

[Storm27m]

OK, put new plugs in it tonight. Old plugs were both black. One looked dry, the other looked oily/wet. Motor still had the intermittent misfire. Did not see any leaking spark. I looked over the coils and they seemed to be in good shape. No cracks or anything that I noticed. Wiring also looked good. While the engine was running I moved over to the left side of the motor (as looking at motor from rear). In an irregular pattern, I could hear a knock coming from the block area. With each knock, I noticed a bit of of jerk to the motor. Couldn't really hear it from the right side. Bad cylinder?

Other stuff I noticed...

Water coming from engine never got really warm. It was warmer than the hose water, but still cool to touch. When revving the engine to higher rpm, water got noticeably warmer, but still only luke warm.

Where is water supposed to come from on an outboard. I have water coming from numerous holes in lower unit, the "pee-hole", around the prop exhaust area, two square holes on the back of the motor mid-section, and one small hole on the mid-section between the motor and the mount.

I'm starting to get that "I'm screwed" feeling. Any advice or should I just run to the local dealer and have them check it out. If so, any idea on what it will cost to have them check it out? Thanks again.

 

[Storm27m]

Or could the knock possibly just be fuel knock?

 

[Storm27m]

Well, I was able to check the compression this evening. Both cylinders were very close to 100psi. I also bought a spark tester and both sparks would jump nearly 1/2" with a bright blue spark. After removing the new plugs that I put in earlier in the week, the top plug was wet/oily with no carbon deposits. The bottom plug was dry with a light coat of carbon. After all procedures, I cleaned and replaced the plugs.

On another note, the misfire and click/knock didn't begin until after a few minutes of running. It seemed like it started when the engine was warmed up.\

Any thoughts?

 

[Bobpaul]

Water's coming out where it's supposed to., and the temperature seems right.

About the knock, take it in and get it checked out. If in fact, it is an engine knock, that's not good.

Did we cover the option that it could be a little water in your gas, causing this knock/engine jerk?

 

[Storm27m]

I don't think we covered the water in gas, but it did this with the old gas mixture and with the new gas mixture I put in the other day. If the knock was a true engine knock, would the knock being consistent or irregular mean anything because it is definitely irregular and doesn't begin until the engine is warm. Thanks again.

 

[Don Wessling]

You have a lean mixture knock if it is irregular and engine jerks at the same time. This means the carb jets are partially clogged, or you have an air leak. do not take it to the lake in this condition, you could sieze a piston. If you want to try a quick carb clean in your barrel, get a can of Power Tune from a Mercury dealer, disconnect the fuel line going to the carbs, remove drain screws from bottom of float bowls, spray Power Tune through gas line until it comes out float bowl drains, install drain screws, spray more Power Tune into gas line. Reinstall gas line. Now if you have a portable gas tank, pour out gas into a clean container leaving about one gallon in tank. Now spray the rest of the Power Tune into the gas tank and shake well. Pump up the ball until fuel system is full. With the hood off, start engine and let it run. Run for a while at partial throttle, idle and full throttle to clean different circuits in carbs. While the engine is running at idle and partial throttle start spraying WD40 around area between carbs and engine, also along crankcase joint. If it revs up you found an air leak. It is easy for the WD40 to get sucked into the air intake for the carbs causing the engine to rev so take that into consideration. If you found no air leak and it still won't run smooth take it to a pro boat mechanic.

 

[Bobpaul]

Love that power tune. Use it as suggested, and you'll also decarbon your engine.

 

[Storm27m]

Thanks for the advice. I'll give that a try when I get the time.