71 Johnson 100 HP Hydro-Electric running too rich

[MichelleBedore]

The motor is still running super-duper rich, no matter what we do, it seems. The spark plugs were so fouled we had to be towed in when it wouldn't restart on the Lake on Sunday. We've been tinkering ever since. The brand new champion marine spark plugs totally wet with oily gas with the choke open.

Is that normal?? (lol) Can this be remedied with "low idle jet" adjustment?

How do you arrive at the *proper* low idle speed, when no adjustment seems to make any difference?

Speaking of idling,

The RPMs seem too high (to me) but we don't have a tach hooked up...even though there IS a tach....no wires coming from the tach under the dash, and nowhere obvious to hook it up at the motor. My husband has a dwell meter, (and a timimg light) but it's for cars, but he's afraid to hook it up to the outboard for fear of frying something....anyone know about the use of a car dwell meter for outboards? And where is the coil you'd hook it up to???

So we're scratching out heads...I'm reading online and trying to garner more insight and info.

Quick recap of facts:

*Fuel pump working fine

*Newly rebuilt carbs

*Fuel lines all clear, pump screen diaphram clean and intact

*Correct fuel mix

*Throttle linkage and choke linkage synchronized

* Low Idle needle turned 7/8th turn

*2-phase choke solenoid bypassed/disconnected, so we know THAT'S not the problem. (we diconnected it because we blew about 10 main line fuses in one day at a lake, and were informed of the choke solenoids in those often cause that problem.

We are wondering if the leaves inside the intake manifold could be all gummed up...after all, we DID run old gas in it which gummed up the carbs and caused a needle float to jam....which is why Nick ended up rebuilding the carbs and putting in new needle floats/seats last month. The floats we installed properly.

It has been running too rich ever since--and was even before the carbs were rebuilt. If we try to slow the idle down, the engine dies.

And yes, we now know (hehe) outboard gas cannot be used if it's been sitting more than a few months--unless it has that outboard fuel stabilizing additive. We have it in the new gas right now, but in the amount directed for "operational use".

Here's a link to a quick video of it running today.

http://www.youtube.com/watch?v=pNAQX95jumg

Thanks to all who have input!!

 

[bigpoppakdog]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

your low idle screws are in the front. You should have 4 of them. Mine had that funny linkage. Took that off and installed bushing replacements that hold each mixture screw in place. Makes it much easier to adjust.

Idle adjustment should be as follows.

Seat each mixture screw lightly then turn them 7/8 out. Adjust them from there while the lower unit is in water or a barrel. Doing this with muffs will not work.

 

[MichelleBedore]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

Thanks for your response. Nick knows about the 7/8 turn...but we DID do this on muffs. Can you explain why doing it in the lake (or a barrel) would make a difference?

My husband is interested to know more about your customizing of those screws with bushings, if you don't mind.

 

[F_R]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

My gut feeling is the problem may not be running too rich, but an igniton problem not igniting the fuel. A dwell meter is useless on that motor. Set the breaker points .009"-.010".

Muffs provide no back pressure on the exhaust. The only real way to do it is in the lake.

There are plastic key-hole shaped friction pieces where the needles enter the carburetor. The correct ones are a fairly light friction so you can turn all four at once. If you want the tighter ones, get some for a 25hp, or other twin cylinder motors.

It ain't the leaf valves, unless you are one in a million.

 

[bigpoppakdog]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

Thanks for your response. Nick knows about the 7/8 turn...but we DID do this on muffs. Can you explain why doing it in the lake (or a barrel) would make a difference?

My husband is interested to know more about your customizing of those screws with bushings, if you don't mind.

don't know the part number off hand, but my idle screws had this funny linkage that connected to the ends of each idle screw. With the new part, you unscrew your screws all the way out and then push these bushings in the opening. You then put the idle screws back in. The screws won't move freely anymore. Makes it easy to adjust from here on out.

If you adjusted your idle while on muffs, when you get it in the water it the motor will not run unless you are lucky to get it started and get the throttle up fast enough. Believe me, I've been there done that quite a bit the past few years trying to get mine set right(ended up having a bad head gasket that finally blew out this year, which was the reason why I had troubles).

 

[Daviet]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

What is the compression readings?
Will the spark jump 7/16" and bright blue?
Is the thermostat installed and working properly?

 

[MichelleBedore]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

Wow, thank you all for your comments and suggestions!

Yes, we have that funny "linkage" thing that adjusts the 4 idle screws...and part of the plastic linkage that is attatched to the push rod is broken where they link up. It's just a small area where the metal push rod rubs on the black plastic part of the linkage. Nick says it "shouldn't matter"...but now I'm thinking it DOES!

Great idea on the use of bypassing that linkage and incorporating bushings to allow more individual and fine tuning of those 4 screws. Thanks for explaining this.

Our next step was going to be to pull the carbs and reinspect. Then if all checked out, we were planning on pulling the intake manifold to inspect the leaves....just in case. As I mentioned, we ran old gas (because we didn't really know any better!) and gummed up the carbs, and one of the needle float got stuck. This occured when we were out for a day of boating at 5 mph in Long Beach Harbor...so we saw a LOT of carbonized shiny black goop coming from the weep holes later when we got home. I'm throwing this out there for the sake of "history"...just in case this has any connection to our current issue.

I will show my husband the other suggestions about the spark and the thermostat. We will also do a compression check as well.

We are fairly new to motorboating. I may be a lady boater, but I am my hubby's "mechanical assistant". We have been learninng all this together side by side. Since medicine has been my profession for many years, mechanical workings seem to come easy to me. All the systems of a boat or car are actually pretty similar to the human body, (only easier!) since they don't have a mind to muddle the symptoms up! haha

Again, we really appreciate all the help and advice offered!

 

[MichelleBedore]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

My husband did a compression check after work last night. The compression readings are:
#1 120
#2 120
#3 118
#4 117-118
We don't own a spark checker yet. Our manual calls for a needle-type spark checker. As far as the thermostats go, we haven't checked it out since we haven't had any overheating issues. I understand it could be running too cold though. I read up in our service manual how to check it by submerging it in hot oil, and how to check to see if the hot horn is working as well.
There is a thermostat inside the choke solenoid circuit, but that was disconnected after it was suspected as the culprit for our problem.
So we will be shopping for those temp. crayons and a needle-type spark checker as the manual calls for. BTW, The manual calls for 100 degree and 130 degree temp. crayons too, and the ones I've seen online were for higher values.....must be because it's that vintage, huh?
We have the Seloc Service manual, but I was fortunate enough to very recently purchase a mint condition Johnson service manual for our exact outboard. It has helped us quite a bit, especially being so new to boating and outboards. Our boat is a very pretty little vintage runabout; a 1964 Glasspar Avalon powered by a 1971 Johnson 100 HP hydro-electric outboard.
We are fond of it, and prefer to learn to work on it ourselves rather than be completely ignorant of how it should operate and troubleshooting.
Again, we feel grateful to everyone on these forums for giving their time & help...especially having the patience and willingness to help the very "new" do-it-yourselfers!

 

[Daviet]

Check around and find a cheap infrared thermomiter, I think harbor freight has them for about 20 bucks.

 

[basbalj288]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

Hey Michelle,
Its a good thing yall are willing to learn to work on them because I had a 71 Evinrude hydro-electric and at least here in Memphis, TN no mechanic it seemed was willing to work on them because they are a different kind of beast they aren't familiar with. And if I did take it to them to say service to the water pump they would say its normally say 100 but since this is a hydroelectric it will be 200 because of the added labor.
Sooo learn all you can and do all you can on that motor is my piece of advice

 

[bigpoppakdog]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

The deal with that stupid linkage is that it connects to each screw and all of them are then controlled at once. I would say without a doubt, get those inserts. It will make your life a lot easier when dealing with idle settings. It sure made mine a lot easier. Now if I need to tweak something, I take the cowl cover off, grab my flat head screwdriver, put it in gear, have someone steer and I can adjust right there on the lake.

 

[MichelleBedore]

Re: 71 Johnson 100 HP Hydro-Electric running too rich

Hi...just wanted to say we are waiting on our infrared laser thermometer and our thexton adjustable spark tester to arrive in the mail. Should both arrive between monday and wednesday. We're chomping the bit to get the ball rolling again. We can hardly wait to throw it in the lake to test and do final adjustments, since all we have are the muffs. What do you all use for a tank? How much room do you need to provide adequate exhaust back pressure for testing?

I've been reading threads on here and found some very useful topics that I printed up to add to our "Repair Binder". Also found the article by joe reeves on how to do away with the linkage that connects all for idles screws and adjust each one. THANK you...my husband was delighted to read all that. Individual adjustment of each screw makes more sense.
You guys are right; NO ONE at any of the local boat repair shops work on these old outboards. Luckily, I find working on them ourselves kind of fun in a way. Sometimes ya just want a simple, quick answer though. But then again, anything worthwhile is never really easy, and always takes time, right? It is very empowering to be ABLE to work on your own motor.