1979 Johnson 115 - a few issues

I have a quick question for you guru's out there. I've been lurking here reading and studying and searching the forums. A LOT of good information here and for that I thank you! here it is:

I recently traded for a 1988 Procraft 1600 V bassboat. I traded a truck I'd had sitting around the yard. Anyway, listened to it run when I went to look at it, but didn't put it in the water. It started pretty good actually, though he could have went out an hour before I got there and warmed it up. Anway, I put it in the water and it ran ok. He had told me he had put seafoam in the gas before storing it for the winter. I am very much a fan of seafoam BTW..... Ok so I filled the tank, put it in the water and ran it about 3 or 4 miles to my favorite fishing spot. It ran good, but occasionally would bog down. It would pick right back up again though. But I smelled gas awful. When I got back in and trailered it, I noticed gas running down the leg. Further inspection showed dry rotted gas lines. Ok, not a real big problem to replace. This isn't my first boat, so I'm ok with doing minor repairs myself.

Replaced the gas lines, went back to the lake yesterday to run it, it wouldn't start. went through the cold cranking procedures, nothing, nada....turn over good would not start. Thought maybe I'd gotten the choke solenoid out of postion, pulled the breather silencer and it appeared to be working well. The battery is 4 years old, and would drop to about 8 on the volt meter when trying to start. So I'm thinking maybe that's it......so anyway, I use the trolling motor to fish some tree tops around the boat ramp, the spots are hitting just about anything on Lake Allatoona here in NW GA btw.....let the motor rest while fishing and tried again. I did finally get it to start, but it wouldn't pick up at all. The fast idle lever made it run, but it was one of those quick hands maneuvers to get from fast idle, to low idle in gear before it died. And it wouldn't pick up at all. Brought it home, charged the battery. Noticed some wires loose, which might explain why the TT didn't seem to be working right. Anyway, put it on the muffs and it starts right up, runs great sitting here in the yard. My question is, was it the battery all along? or am I going to run into problems when I put it back in the water, maybe the back pressure from being in the water vs on the muffs was too much? I'd like some opinions before I drive 40 minutes back to the nearest water to test.

Sorry for the long first post, I know from being on a couple other forums, there's not really such a thing as too much info in the description (as long as it's relevant) Thanks Chaz

Re: 1979 Johnson 115 - a few issues

My crystal ball is broke. Don't know if you will have problems.

The motor shouldn't need a good battery (or a battery at all) to run properly. So you likely haven't fixed anything. It does need a good battery to spin the starter and start the motor.

I have a similar motor to yours, a '88 Johnson 90hp. These motors idle fine (but exhibits your symptoms) on 3 cylinders. My carbs are bad, I will foul a plug in 20 minutes or so of cruzing at 4500 rpm. When the plug starts to foul, it acts like someone has a switch and reduces the engine power. I compensate by going WOT and manage to hold 4500 rpm. The 'switch' gets flipped again and it slams up to 5600 rpm. If I put the controls into neutral, the engine will idle. I can remove the plug wires one at a time to determine the fouled plug. On the good plugs, the engine will die when removed. On the bad there will be no change.

Re: 1979 Johnson 115 - a few issues

Oh ya, welcome aboard cadet.

Re: 1979 Johnson 115 - a few issues

Thanks for the suggestions Charlie. Guess I'll check back for someone with a working crystal ball........

I thought the same thing about not really needing a battery, why would they put the ability to pull crank it if you needed a battery to charge the coils or power packs?

Its just strange that it ran even with the splits in the fuel lines, then wouldn't run at all when actually in the water, but now at home it starts and runs great. Guess I'll know next time I put it in the lake

Re: 1979 Johnson 115 - a few issues

a motor running on muffs has no back pressure so it will run on 2 plugs. the fact it runs better on land is not going to mean it will run any better in the water. It a few year i guess since its been serviced so start with the basics like drainning the carbs and a new set of plugs if that doesnt help then the carbs will proberly need stripping and servicing as i bet not all of the rotten fuel pipe got blown out some proberly went in the carbs and if the fuel pipe rotted the gaskets in the carbs are proberly not doing much better.

p.s a new water impellor would be a good idea as well

Re: 1979 Johnson 115 - a few issues

Thanks Glenn. I have a service manual ordered, so I know that will help. I should have rebuilt the carbs while I had them off, but didn't have time to make the 40 mile trip to the nearest marina for parts. I really didn't want to do that before the manual gets here either. I will also at that time get the water pump kit. I know it wasn't replaced last year because I specifially asked that question. It is peeing a pretty good stream out of the tell tale, but even so I will feel better about it when I get that done.

I was mostly curious about the difference in running it on the muffs vs running it in the lake, and that was what I was looking for. I do plan on putting it in the water at my closest boat dock for making whatever adjustments, and I really already know it needs a link and sync done, just purely because I have to push the throttle so far forward just to get it to start moving.

thanks for the help! this is my first Johnson in several years, my last four boats were all various mercury engines. there are some differences, no doubt about that!

Re: 1979 Johnson 115 - a few issues

glenn property of pam said:

a motor running on muffs has no back pressure so it will run on 2 plugs. the fact it runs better on land is not going to mean it will run any better in the water. It a few year i guess since its been serviced so start with the basics like drainning the carbs and a new set of plugs if that doesnt help then the carbs will proberly need stripping and servicing as i bet not all of the rotten fuel pipe got blown out some proberly went in the carbs and if the fuel pipe rotted the gaskets in the carbs are proberly not doing much better.

p.s a new water impellor would be a good idea as well

Click to expand...

Agree with all of the above. These things'll fool ya sometimes. Sure they'll sound just great on muffs but once ya get em in the water? Pfft!

Here's something I've witnessed a few times but rarely see mentioned. If you think you have the problem narrowed down to one cylinder bank or the other, try swapping the coil trigger wires on the suspect side.

Later motors had a blue stripe on the top wire & green stripe on the bottom. Get it? "Sky blue grass green."

Re: 1979 Johnson 115 - a few issues

before you go 40 miles for the parts. Get a idea of what parts cost so you will know if you are getting value for money. (im willing to pay extra for parts service from a marina but there is a limit to how much extra)

1979 Johnson Evinrude 115 hp Outboard Parts by Model Number

Re: 1979 Johnson 115 - a few issues

wow Glenn, that link is awesome! saved it to my favorites. At $3.50 + for gas, it might be worthwhile just to order the parts from them. I'm looking forward to getting the service manual, it should be here by the first of next week. Being retired gives me all the time I need to work on it, it's just cutting into my fishing time right now, HA. I've never seen such a mess of wires as this thing has stuffed into the back compartment. It's as if some previous owner just ran a bunch of new wires instead of tracking anything down. the only gauges that work are the volt meter and the fuel gauge. I have GOT to get the tach working before I can do to much adjusting, besides the fact that a working tach is a necessity on a boat. studying the wiring stickies gives me the notion maybe just cut out everything and start from scratch. I'd like to add a TNT switch at the motor too.

Anyway thanks for the help! may ride over and put her in the lake tomorrow just to see what happens.....I will post the results if I do.

Re: 1979 Johnson 115 - a few issues

Your battery needs to crank the engne at least 200-250 rpm's in order to fire that ignition system. Once started, the engine runs on it's own internal electrical power. (it does need the battery for operating the power trim.) As glenn mentioned, that engine will seem to run fine on 2 or 3 cyls when sitting on the trailer. You need all 4 firing when the prop is 20" underwater. So-check for spark. You may have spark when the engine is cold. Once it warms up, weak ignition components tend to fail. Once warmed up, put a timing light on each plugwire. The flashes in the gun will show the quality of spark to each spark plug. Will show misfires, no fires, etc. The coils on that engine are pretty reliable. If you find no spark on one head or the other, you cans swap power packs for testing purposes. (2 on that engine.) Each pack controls the spark to one head. If a nospark condition moves when the packs are swapped, you've found the problem. Great ignition troubleshooting info in the orignal factory manual, or this website: cdielectronics.com If you find the ignition system check out ok, then it's a fuel problem.

Re: 1979 Johnson 115 - a few issues

thanks Emdsapmgr. I have one of those testers I can put on the plug wires, I need to do that. The thing is it was running good before I took the carbs off and changed the fuel lines. I still need to do some basic tests on it though. I have managed to get the tach working following Joe Reeves' quick test post. On the muffs I have it idling @ 1200. I wanted to take it to the lake this morning, but we have storms moving in so it will have to wait. In working on the tach, I laid down and crawled under the dash to check the wires on that end, and found a wasp nest that made me almost hurt myself getting out of there, HAHA. I got em tho before they got me!

thanks for all the help, will keep posted on results

Re: 1979 Johnson 115 - a few issues

back again. The storms held off till this afternoon, so I took her over and put her in the lake. Before I left, I started her up on the muffs, let her sit there and run and get good and warmed up. 30 minute drive to the lake, put her in she started up sitting at the dock, but when I pushed away and tried to get her to go, she went dead and wouldn't start back. Again, she was running fine last week, until I took the carbs off and replaced the fuel lines. Going to pull the carbs tomorrow, soak them and put the kits in them, change the impeller while I got the carbs off. Will be checking the plugs and the strength of the sparks while I'm working on it. Will update as I go along. Any other suggestions while I have it 'in repair' will be greatly appreciated. Chaz

Re: 1979 Johnson 115 - a few issues

I picked up my carb kits and water pump kit. My service manual came in the mail today, YAY. I have the carbs off, disassembled and soaking overnight. While they're off tomorrow afternoon before I put them back on I plan on rebuilding the water pump, so it's easier to get to the shift lever to take off and put on. I can't find anything in the manual that tells me if I should have it in forward, reverse or neutral before I drop the lower unit. Am I overlooking it, or does it not matter? I always left the mercs in neutral, but I'm thinking I read somewhere to put this Johnson in reverse? This is my first Johnson is several years, any help is greatly appreciated! thanks Chaz