1974 85HP Johnson excessive 2 cycle drip help

[skier167]

My 85hp outboard has an excessive 2 cycle drip problem and I'm trying to find a way to make it not do it as much or stop it all together. I have searched the internet and see that some excessive fuel drip is ok but I think my motor is excessive. When I come home from running around on the lake I have to put a piece of cardboard under it to catch all of the unburt fuel. There is so much of it that comes out that I have to wipe off the lower unit a few times to get it all off the motor itself.

The stator was replaced at the beginning of the year and I'm not sure if a coil is bad or not. I checked the spark plugs and all of them have carbon on them from burning. I did see online that one of the coils isn't putting out enough power the spark on the plug will not be enough to ignite all of the fuel in the cylinder.

What is the best way to check coils to see if they are putting out the right amount of electricity? I do have a volt meter to test with just not sure how to go about doing it.

Also I looked at the carbs and they seem to have been rebuilt not that long ago since the gaskets look new. Could it be caused by the carbs not being synced up?

I had this issue with Pennzoil 2 cycle oil and switched during the middle of last summer to quicksilver and still having the same issue.

Is there anything else I should be looking at as a culprit?

I do want to decarb the engine to get the gunk out but do not want to do that till I've figured out the problem.

any feedback is greatly appreciated!!!!!!!!

 

[boobie]

Re: 1974 85HP Johnson excessive 2 cycle drip help

Do a cyl drop test on it to make sure it's running on all 4 cyl's. If it is do a good decarb on it and then see what happens.

 

[emdsapmgr]

Re: 1974 85HP Johnson excessive 2 cycle drip help

Hard to tell what you exhaust leak issue is, without a picture. If the mechanic that last replaced the water pump impeller did not re-install the gearcase to exhaust housing seal, you will get a lot of black, tarry exhaust residue at the mating joint of the gearcase and midsection.

 

[skier167]

Re: 1974 85HP Johnson excessive 2 cycle drip help

Attached are photos of the motor and the floor where it sits. It was last run on Memorial day.

 

[emdsapmgr]

Re: 1974 85HP Johnson excessive 2 cycle drip help

I'd pull the lower unit down and check to see if the rubber grommet is still in place between the top of the gearcase and the underside of the exhaust tube. Should be a 5-sided large rubber grommet in that joint. Original part number: 314937. It's job is two fold: direct the unburned tarry exhaust out the exhaust by the prop 2. keep exhaust heat from getting in contact with the plastic impeller housing and possibly deforming it over time.

 

[skier167]

Re: 1974 85HP Johnson excessive 2 cycle drip help

I'd pull the lower unit down and check to see if the rubber grommet is still in place between the top of the gearcase and the underside of the exhaust tube. Should be a 5-sided large rubber grommet in that joint. Original part number: 314937. It's job is two fold: direct the unburned tarry exhaust out the exhaust by the prop 2. keep exhaust heat from getting in contact with the plastic impeller housing and possibly deforming it over time.

emdsapmgr I replaced that rubber grommet over the winter when I dropped the lower unit to reseal it. What about exhaust port being clogged? I am going to take the boat out to the lake hopefully in the next few days to decarb it. I have not decarbed it in the year that i've owned it and pretty sure it's due for one.

 

[emdsapmgr]

Re: 1974 85HP Johnson excessive 2 cycle drip help

It is normal to get some black, tarry exhaust residue out of the prop area. Very unusual to get it at the bottom of the midsection. The factory design of midsection seals and grommets are to prevent the problem you are experiencing. That's a lot of leakage. Some other thoughts. 1. not unusual for that exhaust grommet to become misaligned during installation of the lower unit. 2. Possible that the gasket at the top of the exhaust tube (underside of the exhaust adapter has failed. (you might have noticed if that tube appeared loose, when you put the new gromment on it.) A pretty rare type of failure. 3. Possible that part of the powerhead base gasket has failed. If the front part of that exhaust chamber gasket fails, exhaust will (leak) go down around the driveshaft. It's an unusual failure, as you usually notice exhaust gas exiting from just under the powerhead as it runs-the more common failure. Any chance this engine was in saltwater at some point? Decarbing is a really good thing every year or two. Helps clean the combustion chambers and ringsets. Probably won't do much for this problem, however.

 

[skier167]

Re: 1974 85HP Johnson excessive 2 cycle drip help

It is normal to get some black, tarry exhaust residue out of the prop area. Very unusual to get it at the bottom of the midsection. The factory design of midsection seals and grommets are to prevent the problem you are experiencing. That's a lot of leakage. Some other thoughts. 1. not unusual for that exhaust grommet to become misaligned during installation of the lower unit. 2. Possible that the gasket at the top of the exhaust tube (underside of the exhaust adapter has failed. (you might have noticed if that tube appeared loose, when you put the new gromment on it.) A pretty rare type of failure. 3. Possible that part of the powerhead base gasket has failed. If the front part of that exhaust chamber gasket fails, exhaust will (leak) go down around the driveshaft. It's an unusual failure, as you usually notice exhaust gas exiting from just under the powerhead as it runs-the more common failure. Any chance this engine was in saltwater at some point? Decarbing is a really good thing every year or two. Helps clean the combustion chambers and ringsets. Probably won't do much for this problem, however.

I will pull lower unit hopefully this weekend to check on that gromit. I decarbed the engine today with the 16oz of seafom to 1 gal of gas method. I ran for 15 mins then let it sit for 15 mins and repeated. The amount of drip is what made me think that a pwr pack went bad or is on its way out and the excess unburtn fuel is being spent out of the exhaust. I do not have exhaust coming out from below the power head. To the best of my knowledge this motor has never been in salt water. I live in ohio and the motor was titled in ohio from the previous owner. I am thinking that pulling the power head is going to be in my near future.....insert cheers of joy lol.

What about dirty or unsynced carb?

 

[emdsapmgr]

Re: 1974 85HP Johnson excessive 2 cycle drip help

I was assuming that the engine was a good runner when the boat is on the water. If it does not run on all cyls when in the water, it is possible that it's not firing on all 4 cyls. That certainly can aggravate the oil problem-extra unburned fuel/oil going down the exhaust. It does not explain the excessive leak, however.

 

[skier167]

Re: 1974 85HP Johnson excessive 2 cycle drip help

I decabed engine yesterday afternoon out on the lake and much to my suprise there is not oil leaking out this morning. Going to give it a day or so to make sure that it's taken care of but I would have had the oil mix coming out by now. I will still pull the l/u to check that gasket from the l/u to the exhaust housing. I also think I might run another decarb on it just to make sure it's good and clean

 

[boobie]

Re: 1974 85HP Johnson excessive 2 cycle drip help

Not a bad idea to run another decarb. If it helps it more, do another one. Yrs back I had to do one four times to get the mtr to run right.