Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Johnson 115 Problem
Posted by gerobertson1 on 07/02/08 - 6:53 AM
#1
It seems like my engine is not burning all of it's fuel. Upon running I could see a small bit of oil in the water. I am really concerned about the environment, so for me this is unacceptable. It seems to be firing on all four cylinders, so I am wondering where the problem is. My only guess is the carburetor needs an adjustment.
I can provide more details if anyone needs more info to diagnose what is happening. The engine is an older 115, probably like and 84'.
Posted by Derwd24 on 07/02/08 - 7:00 AM
#2
Well the older two strokes are pretty inefficient by design... When the piston moves down the cylinder to the bottom, both the intake and exhaust port are open at the same time for an instant and some of the unburned intake charge does pass right through the cylinder into the exhaust. My guess is this is what you're seeing if you haven't noticed a change in the performance of the engine...
I feel the same as you and that's why I've limited my search for a replacement engine to a DI model as the direct inject eliminates the intake port being open at the same time as the exhaust, and is one of the reasons those engines get such clean emissions ratings.
Posted by CES on 07/02/08 - 7:13 AM
#3
gerobertson1. I echo what Derwd24 said. For an engine as old as yours, fuel/oil in the water is normal....my 1986 40hp yamaha does the same thing. There isn't a whole lot you can do about it except buy a newer, more efficient motor.
Posted by gerobertson1 on 07/02/08 - 7:29 AM
#4
I guess that would make sense. To bad a newer engine cost so much. I mean this one is running pretty fantastic for its age and certainly gets the boat moving like hell. It is just with all the knowledge that we have about our impact on the environment it really makes you want to be doing the right thing. Then again, me dropping $8000 on a new engine might severely impact the environment in my home life! HA.
Posted by egerrity on 07/02/08 - 7:41 AM
#5
I would imagine that most of that fuel on the water evaporates in a couple of minutes?
Posted by MW on 07/02/08 - 9:07 AM
#6
I feel the same way, I won't even use soap to rinse down at the dock, I'm always pulling plastic bags out of the water when they go by, I've been bit by many "Herring Gull's" while unraveling someone else's monofilament line off them. We do what ever we can to help.
mw
Posted by ioptfm on 07/02/08 - 12:54 PM
#7
It is a concern that oil and fuel are spilling into the water but as stated above, there is very little that can be done about it. The one consolation is that as the boat is running, it is introducing less waste into the water and also what does go in is pretty much disapated while you are running.