mercury outboard has rabies and the vaccine isnt working :( (with video) -help

[walleye_hunting]

Hi there guys,
New to the forums here,
I have searched through forums for 4 days and still cant find anybody with this issue.
My engine is a 1980 mercury 115hp inline 6.
I purchased the motor and it needed a bit of work.
I replaced carbs and everything in the top end of the motor, Finally got it fired up and bam my engine started frothing at the mouth.

So I assume, Ok gaskets are gone in the lower end. (**Note** motor has only been run on muffs)
Dropped the lower end and changed all the gaskets, Waterpump housing, orings and impeller
Here is the internals
The old internals immediately after dropping lower end

Bad gaskets I was assuming this was a huge problem for sure

Old impeller, Seemed not too bad (Water tube removed in this picture by me)

ordered the kit online and replaced everything i could find to replace. all the way down to the bearings.


After getting the engine(lower end) back together, I refilled the gear oil and fired it up on the muffs,

Withing 30 seconds --->


Perfect stream coming from the pee hole but I cant understand where this foam is coming from or how to fix it,
I am very mechanically inclined but by no means a mechanic.
I hope my post is detailed enough to receive some insight.

I look forward to being a part of this online community, Many of the posts I have found on here have been very useful to me and I hope to be able to contribute just the same.

Safe boating everyone

 

[Chris1956]

When 2 cycle oil is mixed with water it can get foamy. Also, maybe the motor was winterized, by spraying lots of fogging oil into the carbs to lubricate the innerds for the lay-off. When you run the motor all that fogging oil has to come out and will mix with the cooling water.

I really cannot see the foam, as the picture is not clear enough.

 

[iggyw1]

I can see the foam in the video. That foam is definitely from your 2-cycle oil mixing with the exhaust gases. It is discharging from the port in the rear of the motor (and probably thru the hub in the prop as well). #1- There looks like way too much oil in the gas mix (should be 50:1 mix) #2- the thermostat would have nothing to do with this discharge out of the exhaust ports at the rear of the motor above the water line just under your motor power head, but the poppit pressure valve does and that may have stuck open or is missing!

If an adjustment of the correct oil mix does not help the situation, I would change the poppit valve And the thermostat while you are in the thermostat housing. Easy fix! Like Chris stated too, there may have been a lot of fogging oil in the head too. The problem is definitely from the oil in the power head.

 

[walleye_hunting]

First of all,
Thank you very much for the input, All fantastic suggestions.
I am not too familiar with this poppit pressure valve however i will do some research and look into that
A quick update,
yesterday I took all the new gaskets out and redid them all with form a gasket, just incase the mating surfaces were not perfect as there was water in the gear oil again.(motor is 35 yrs old after all)
I was almost positive this was gear oil being mixed and creating foam but now you have definately pushed me towards thinking the foam is not from the lower end at all and I was skeptical as to how it was making its way up the motor, however there are spurts of water coming out of these ports as well. the motor is not subnerged but just muffs so I dont know how the water would be getting up there either except for the water tube.
I am not sure at all if the engine was fogged or not but there has been an awful lot of foam I would almost think it would have been cleared out by now.
So Also yesterday I emptied all the gas out of the tank the lines and the carbs, Reassembled and refilled with 91 octane mixed 50:1 with mixing bottle.

Here is the result after 15 minutes,
Ran perfect for 5 minutes no foam and then bam an avalanche of it
here is a picture from todays foam catastrophy

 

[rookie456]

I have a 1980 80hp Mercury, inline 4cylinder. I believe the 115 and the 80 are about the same design. I know my engine does not have a thermostat or a pop it valve. I also have foam from my motor I just rebuilt, but the foam I have doesn't show up while running, it drips from the prop after running. On my thread, I'm being told it is a water leak on the exhaust side of the engine, or a power head base gasket leak. I would think you might have the same issue.

 

[Faztbullet]

Pull bottom plug and see if its milky also, if it is it the lower crankshaft seals....

 

[Chris1956]

No poppet or thermostat on inline six motors.

If you see water in the gear oil, replace the water pump base driveshaft seal. I saw where you already replaced the water pump base oring and gasket.

 

[walleye_hunting]

could you please point me in the right direction. there is water in the gear oil after only 15 minutes, I thought i replaced all the seals but I feel like there should be something above the bearings but below the water pump base
Drive shaft seal --->http://www.crowleymarine.com/mercury-outboard/parts/683_190.cfm?mdl=7YFVS0


Thanks

 

[walleye_hunting]

Is it possible the number 15 could cause this?
I do not remember replacing this oring or even seeing it,
I did replace the seals on the waterpump base though
thanks

 

[gm280]

Oh I do like that inline six Mercury 115. I had one on a Bass Boat and loved it. Sounds great as well. I never had any problems with mine in all the years I owned it. It would crank so quickly, that I couldn't get the key back to run position quick enough before it was sounding mean! I have to agree with 2 cycle oil mixture being the foam issue. Seem oil mixed with water is what you are experiencing. But make sure you have a sealed lower unit and if so, happy boating... :thumb:

 

[Chris1956]

Obviously the oring (#15) could cause water leakage. However, I vote for the driveshaft seal in the base of the waterpump. Your diaghram is confusing, as normally #17 is the only seal. Not sure what #18 is. Maybe they are for different serial groups?

Anyway, take your serial number to a dealer (or order online) and get the correct water pump base. Remove the old base, and clean the driveshaft with fine sandpaper and paint thinner to ger her clean. Now oil it up and oil the new water pump base seal. Install the base with a new base gasket (grease both sides) and a new Oring (grease it as well).

 

[walleye_hunting]

#17 and #18 are actually attached to the inside of the waterpump base

 

[walleye_hunting]

So i have ordered a new waterpump base which includes new seals around the drive shaft(orings) I am going to swap that out and let it run since i do still have water in the lower end after letting it run.(Milky oil) I think that is why i was associating the foam with the lower end but cant imagine how it would push up past the exhaust gasses and out the ports below the cowling

I dont understand where any water could be getting in.
i have a 60 litre gas tank which is completely sealed inside the floor of the boat with no way for water to get in all my hoses fuel lines and fuel filters were changed when i did the carbs last week
and the tank was drained before ever running the motor.
Thank you for all your help and input guys i will update the post once i do thos work and see if there is any change
the amount of foam coming out of the exhaust port is rediculous foaming out and all over the driveway.
I am afraid if i just let it run something os going to break on me.
There is alot of money put into this motor and i cant imagine taking it to a mechanic ar this point.

Hoping to resolve this issue via these forums and help someone else as well having the same problem as this really is a great motor!

 

[rookie456]

When you take the lower unit off to change the pump housing, I would take a garden house and hook it up to the water tube and run the engine without the lower unit on. If it foams without the lower unit on then you eliminate the leak being in the lower. Maybe the water jacket cover is leaking inside the exhaust cover.

 

[walleye_hunting]

**UPDATE**
Motor is finally fixed.
Turns out it was actually a lower unit leak.
Removed the shift shaft bushing and cleaned up the threads,
When I had the lower unit off I accidentally moved the shift shaft, The only way I could get it back to position was with a pair of vicegrips. Problem is when I turned it I burred the shift shaft a little bit and it must have damaged the seal in the new bushing.(wont do that again)
Sanded down the shaft a little put a new bushing in and put a pressure test on it.
Pressure test didn't move after an hour of being on.
put it all back together and ran flawless.
Took it out on the water and it ran like a gem.

Thank you for all your help and input, Your advice truly helped me solve the problem