Gas Leaking From Outboard Motor

[kshays]

Took the boat on the lake a few days ago and on the way back had to use the trolling motor for about 1.5 miles to get to the dock.  Motor started to lose power and then would not start at all.  Got it home and only thing I have done so far is a visual inspection and this is what I saw.

 

 

I have not taken anything out yet and was wanting to see opinions if any from what the video shows perhaps.  I've been told the block is more than likely cracked, but hopefully it isn't.  The carbs have all been rebuilt last summer and all new fuel lines, fuel pump, fuel filter also.  Trying to decide if it's worth checking myself or taking it to a marine service center or not.

 

Thanks!

[Way2slow]

Sorry, but there's nothing about the block that can cause that.  I would check a little better, my first assumption would be it's coming out the carburetor.

 

[MN Fisher]

Just now, Way2slow said:

Sorry, but there's nothing about the block that can cause that.  I would check a little better, my first assumption would be it's coming out the carburetor.

 

My first thought is an failed gasket seal...which can happen hours/days/weeks after installation.

[Way2slow]

Actually, I think it's a stuck float needle in the carb. That would cause it to flood the engine and not restart.  Also, there is carb bowl vent hole in the top of the carb.  A stuck needle would cause it to squirt out of that vent hole onto the tab above it, making it look like it's coming out block.

Stickley my personal thought. 

[kshays]

Thanks guys for the input.  I hope to start looking at it in the next day or two.  I did not think a cracked head would do that either, but i'm not an expert on outdoor motors so i wanted to ask you guys for some input first

 

ty,

 

Kevin

[kshays]

Finally got around to checking on the motor this weekend.  Last fall when I did a compression test the results were 131/131/130, however since I am not able to get the motor running at this moment I decided to just do a compression test with the motor cold to see what type of results showed.  This time around they were 101/65/80 which I thought the rings were probably shot then.  I am assuming even on a cold engine the differences between them should not be that bad.

 

 

[kshays]

Update:  Carbs looked fine.  Replaced water pump and gear oil last night just because I already had it ordered before this happened.  Gas is no longer leaking out (not sure why), however the top and middle is not sparking.  Will try to test all the coils and wires out tonight if possible.

[kshays]

Update:  All coils look good, spark plug wires look good.  The top two wires coming from the power pack to the top 2 coils are not sparking though.  Checked coils with DMM and swapping them around as well.  So it looks like the top and middle wire going to the pack is messed up or perhaps the stator?  Is there anyway to check those wire plugs that connect to the coil besides just replacing the pack?

 

ty,

Kevin

[kshays]

Just replaced power pack, still no spark on top two.

[Way2slow]

Not sure what model or year you are working and if it has points or timer base.

Assuming it's late enough to have a timer base, you really need a Peak Voltmeter or something that converts RMS voltage to Peak to check it,  Also, not likely anything to do with stator, it does not control the spark

You should see a linkage go from the throttle arm to back underneath the flywheel that moves when you move the throttle linkage.  This linkage is connected to the timer base under the flywheel, this is what generates the initial spark and controls timing.  There are pickup coils molded into a doughnut ring around the crankshaft.  The flywheel has a magnetic ring on the inside, around the crankshaft hole.  As the flywheel spins, these magnets make the pickup coils produce a voltage signal that goes to the power pack.  The power pack amplifies that voltage and sends it to the coil.  The coil then amplifies it enough to fire the spark plugs.  You will need a manual on the ignition system to trouble shoot.  There is a procedure the check the timer base with an ohm meter but sometimes that's not accurate and the more reliable way is with a Peak reading meter.  Not a meter that stores it's peak voltage, that's not the same animal.  That just means it stores the highest RMS voltage it saw.

Shotgun trouble shooting, just throwing parts at it, can get very expensive on outboard motors.

 

[kshays]

Hey Keith,

It is a 1986 Johnson 70hp.  I do have the manual on cd as well now.  I am not sure how long ago some of the parts were replaced so I have been replacing some parts that appear bad just in case   I really did not want to replace the stator unless I had to.  It sure can get expensive by just throwing parts at it, which I really do not want to do without knowing if it's bad or not.

 

I'm pretty sure my dmm just stores the peak voltage.  I may also see how much it would cost a marine shop to take a look at it if I cannot find what's causing the issue.  

 

ty!

[Way2slow]

Like I said, it's not the stator, some models do have one coil on the stator that's used for cold start advance but I've never know of that causing one to loose ignition.  The time base is a separate animal from the stator.  

A little word of warning, most so called outboard mechanics don't know how or have to equipment to trouble ignition problems.  There is also the issue of it can be very time consuming and at $100 or so per hour it's easier for them to just replace it.  Plus, sometimes about the only way to be sure it's a certain part is to put another one on.   The problem there is, if that wasn't the problem you bought it anyway.  That turns into one of the parts that caused the part they finally replaced that fixed it to go bad.

You can easily make you a digital voltage adapter (DVA) module for a couple of bucks to measure peak voltage.  It's nothing but one diode, a capacitor and small resistor.  The diode rectifies it, the capacitor stores it and the resistor prevents rapid bleed off from the capacitor.  Take an old set of test leads cut them into for one end to plug into the meter and solder to the parts and the other end to measuring and it's soldered to the parts.  If you shop around, you can also buy them.

By the way, I have had several bad timer bases, it's not an uncommon part to fail, but they can get kind of proud of them.  Also, don't buy used parts, too many AH's will stick bad ones on ebay after they replace them.  The only time I will use used ignition parts is if I take them off a known good running motor myself, and I know for a fact that motor ran good.

 

[kshays]

That is good news on the stator. I've learned a lot since last year on outboards, but there is just so much more I am lacking.  Youtube videos only go so far and cannot replace real world experience someone has.  If this was a server/pc I would be in my comfort zone as I've been doing IT for almost 30 years now, but it's not and it's something I would like to learn.

 

That is what was in the back of my mind taking it to a marine dealer, they would just replace parts at random.  The DVA looks simple enough to make.

 

I have been looking at the model # of the engine and either buying OMC/Johnson or CDI parts.  I won't buy anything used to replace as I do not know the history of it for the motor.

 

Thanks for the info Keith.

 

Kevin