77 Evinrude back to life. Help please

Hello everyone, we just got a 77 evinrude 4 cyl. model 115793 115HP motor running after about a 4 year rest. It was running when last put to rest. We changed the plugs oiled the cylinders, put in some new fuel mix and she started right up. We changed all the fuel lines, as we thought there was a leak. Still some fuel donw on the adapter plate.

I've done a searxh an could not find a similar poblem listed.

Looking at the carb end, the lower right side of the power head there is a port that is puffing out a oily gas mix. (looks unburnt) This is not the air silencer drain connecion, as that is intact. (A hose from the bottom right of the silencer to the bottom middle of the intake manifold)

The service manual I have does not show or mention this port. It is not a lot of fluid, but you can see the air puffs moving it along the the bottom of the adapter plate.

Is this normal? Should this be plumbed to the carbs? If I add a hose to the port, the engine will backfire a good amount (wet my whole hand) through the port.

The engine misses as I run up the RPM in neutral. I will be going over the ignition system with the help on the new service manual.

TIA, Mike

Re: 77 Evinrude back to life. Help please

Could you provide a picture of the area you are describing?

I have nearly the same engine and have done extensive work on it, maybe I can help if I can picture where you are talking about.

After sitting for 4 years, you need to completely disassemble the carbs, take out the jets, clean them thoroughly, and rebuild the carbs with OEM carb rebuild kits. For my engine they were $29.10 each, and with the manual and help on this website I rebuilt them without ever having done it before. It's pretty straightforward work.

Do this before you start troubleshooting ignition. If the carbs aren't working properly you won't be able to diagnose anything else. After I got mine rebuilt I was able to troubleshoot the ignition problems I had, and not the engine runs like a top.

Get that picture if you can, and I'll see what I can dig up.

Re: 77 Evinrude back to life. Help please

I ordered a OEM carb kit but it is only for one carb so I need to get another one.

I've rebuilt many car carbs so I'll do the carb rebuilds as soon as I get the other kit in. I was surprised it started without rebuilding them.

I'll get a picture in the next couple of days. It's not at my house.

Thanks!

Re: 77 Evinrude back to life. Help please

http://www.youtube.com/watch?v=o5cxBMDezuU&feature=PlayList&p=927682907A9BA566&playnext_from=PL&playnext=1&index=2

Give this a couple of views. It gives a good way to pull the welch plugs and replace them. It's very important to clean the intermediate orifices and the area below the welch plug.

Here's a great reference thread:
http://forums.iboats.com/showthread.php?t=244013

If you don't have an orifice removal tool use the intstructions to make one. I just happened to have a screw driver with multiple heads that just happened to fit. I soaked my bowls in carb cleaner overnight and blew everything out with compressed air, and when I took the jets out they were still gummed up. Then I used pipe cleaners (The kind in the craft aisle) to clean the orifices.

I'll keep checking back, let me know if you need anything else! Good luck!

Re: 77 Evinrude back to life. Help please

Thanks for the references.

Re: 77 Evinrude back to life. Help please

Any chance that the powerhead base gasket is failing?. It's not unusual for these engines to leak some exhaust into the cowling when that base gasket starts to fail.

Re: 77 Evinrude back to life. Help please

We cleaned up the complete adapter plate to look for any possible leak sites. The powerhead gasket seams intact, the only place we get the oil/gas out of is this mystery port on the powerhead at the lower right corner when looking at the carb end. I will get a picture tomorrw and post it late tomorrow night or early Thursday morning.

Thanks

Re: 77 Evinrude back to life. Help please

Here are the pictures. The highlighter is pointing at the port. You can see the silencer vent hose to the left. It puffs the gas/oil mix to the adapter plate directly below the carbs.





I 've had one person say it may just be a crankcase vent.
It seams that would make a heck of an oil slick. Then again I guess old school cars just vented the crankcase to the road.

I will be disassemnling the carbs today for soaking.

Thanks for your help.

Re: 77 Evinrude back to life. Help please

Well I'm stumped. I looked at my motor and I'm just not seeing it. I looked up the Evinrude parts diagram and couldn't find it either.

Hopefully someone with a lot more experience will chime in.

Re: 77 Evinrude back to life. Help please

Is that the fitting for the pulse hose for the fuel pump?

Re: 77 Evinrude back to life. Help please

Thats what it feels like but on the 115HP engine the fuel pump is mounted directly the the powerhead with the gasket shown. I assume the pulses go directly into the back of the pump. There are no extra fittings left open on the fuel pump.

Now you have me thinking...

The 85HP uses a pulse hose. Could this be an 85HP power head?

Re: 77 Evinrude back to life. Help please

Plug it off and call it good.

Re: 77 Evinrude back to life. Help please

I have a 1974 115HP Johnson. My motor appears to be very similar to yours and on my motor that nipple you are pointing out is connected to my fuel pump with a hose. Definetly appears to be the air/pulse hose that makes the fuel pump work. It is a much smaller hose than the other fuel line hoses. I can post pics of mine if you'd like but I cannot guarantee yours is the exact same as mine. If yours is the same as mine I cannot see how your motor could run without the hose connected.

Re: 77 Evinrude back to life. Help please

Wishiniwuzfishin said:

I have a 1974 115HP Johnson. My motor appears to be very similar to yours and on my motor that nipple you are pointing out is connected to my fuel pump with a hose. Definetly appears to be the air/pulse hose that makes the fuel pump work. It is a much smaller hose than the other fuel line hoses. I can post pics of mine if you'd like but I cannot guarantee yours is the exact same as mine. If yours is the same as mine I cannot see how your motor could run without the hose connected.

Click to expand...

That was the same on my 1976 115. It is the pulse line for the fuel pump. The 140 from 1977 up has the fuel pump mounted directly on the engine, but not all 1977 115s - just the extra long shaft ones.

Re: 77 Evinrude back to life. Help please

Here's mine. 1974 115HP Johnson 20" shaft.

Re: 77 Evinrude back to life. Help please

Wishiniwuzfishin said:

I have a 1974 115HP Johnson. My motor appears to be very similar to yours and on my motor that nipple you are pointing out is connected to my fuel pump with a hose. Definetly appears to be the air/pulse hose that makes the fuel pump work. It is a much smaller hose than the other fuel line hoses. I can post pics of mine if you'd like but I cannot guarantee yours is the exact same as mine. If yours is the same as mine I cannot see how your motor could run without the hose connected.

Click to expand...

Agreed, that's where mine connects as well.

Re: 77 Evinrude back to life. Help please

It looks as though the newer intake manifold with port built in is on the engine, so I would use it and cap the nipple. Make sure it's airtight; use a clamp.

Re: 77 Evinrude back to life. Help please

The carbs are done, that was really easy. No adjustments.

OK, this is either a crossover assembly from the factory and the port cap is missing, or previous owners swapped parts during a rebuild. I will be installing the carbs on Wednesday and plug up the port, then give it another test run on the stand.

Thanks everyone for your input!

Re: 77 Evinrude back to life. Help please

WooHooo! Engine is running very well.

The fuel pump cover was sucking air. This caused the engine to run about 5 sec then idle down and stall. Uh-oh...

We fixed that and it started up and idled real smooth. No more misses at higher RPMs.

We need to get 2 new tires, registration and a tach for the maiden test voyage.

Thanks again for a the help!

Re: 77 Evinrude back to life. Help please

I hope that fixes it! Good luck.