Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 1984 Johnson leak - lower unit

Posted by Sebastian on 01/17/12 - 8:32 AM
#1

Hi all,

I have a slow leak out of my lower unit Gear housing. It is coming out of one of the 4 bolts above the lower unit. It looks like unburnt fuel/oil mix.

1984 Johnson, 75 hp.

Is this anything to be concerned about? I have attached 2 pics on my personal page.

Thanks in advance!

Posted by Gamalot on 01/18/12 - 5:12 AM
#2

I am NO expert on this but that looks pretty normal to me. That section of the motor is the exhaust housing and there could be a rubber seal or gasket not fitting just right or worn that is allowing some of the unburnt fuel/oil to get by. The fix might be in the removal of the lower unit to see what is going on but other here should have a better grasp of your motor and it's design. I have seen what your pictures show on quite a few 2 stroke motors.

Posted by CES on 01/18/12 - 5:52 AM
#3

Sebastian wrote:
Hi all,

I have a slow leak out of my lower unit Gear housing. It is coming out of one of the 4 bolts above the lower unit. It looks like unburnt fuel/oil mix.

1984 Johnson, 75 hp.

Is this anything to be concerned about? I have attached 2 pics on my personal page.

Thanks in advance!


My comments mirror Gamalots......that looks like unburnt oil/exhaust residue to me too. I don't think it's a major problem at all.

Edited by CES on 01/18/12 - 5:53 AM

Posted by Sebastian on 01/18/12 - 7:01 AM
#4

Thanks guys. What I think it is, is gas oil mix that drips out of the carbs when I have the motor tilted up for transport. Thanks again!

Posted by cwk6 on 01/18/12 - 12:42 PM
#5

These old engines all gather oil or residue in one place or another. If it is very slow (as it appears to be) I 3rd the "dont worry about it"

Posted by Gamalot on 01/18/12 - 4:49 PM
#6

Sebastian wrote:
Thanks guys. What I think it is, is gas oil mix that drips out of the carbs when I have the motor tilted up for transport. Thanks again!


That seems like a real possibility Sebastian. The fix for that is to disconnect the fuel line and run the motor until it drains the carbs dry before you tilt for travel. Do this while the engine is still in the water and getting cooled.

All of these two cycle motors have a tendency to leak un-burnt fuel/oil mixtures because many are not metering the oil to fuel ratios. I see it much more in motors that do a lot of slow idling as in trolling. This is a very tricky subject but engines that run at higher RPMs require more oil in the mix than engines that run on low RPMs. The mix burns much more efficiently when the spark plugs are getting juiced. The engines with VRO (Variable ratio oiling) are designed to adjust the mixture and prevent this leaking or un-burnt exhaust if working properly.

Posted by Sebastian on 01/19/12 - 7:06 AM
#7

Thanks Gamalot. My motor doesn't have VRO so I mix. I have thought about drainining the carbs when I run fresh water through the motor at the end of a day.

How is your boat coming along - any new pictures?

Posted by Gamalot on 01/19/12 - 8:49 AM
#8

Try running the fuel out and let us know if this helps. You could also be running too rich of a mix but that gets rather technical.

Thanks for asking about my project. She is safely parked in the barn at present and with temps in the sub zero range I am drilling holes in the water to fish. Pics to follow when I get finished and try to set up a project page.

Posted by zappaddles on 01/19/12 - 12:55 PM
#9

Sub zero temps. B-r-r-r-r-r-r-r
Zap

Posted by Gamalot on 01/19/12 - 1:28 PM
#10

zappaddles wrote:
Sub zero temps. B-r-r-r-r-r-r-r
Zap


Minus 3 this morning and a high of 21 today.

I guess you won't be going ice fishing with me then?

One of my brothers lives in Atlanta and while visiting home he came ice fishing with me. Not a good idea and I do believe the blood gets thinner and you southeners are not able to deal with cold as well.

Back when I first retired we moved to Florida in April and moved back home in November. We just could not stand the heat and humidity. On beautiful days I felt like a hermit hiding in the house with AC.