1983 Johnson 70 horsepower outboard idle?

Big Bubba

Senior Chief Petty Officer
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Apr 11, 2007
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746
Good day to everyone,
I have a question for all of you. I just bought a 70 horsepower model# J70ELCTE Johnson outboard yesterday for $700.00. I mounted it on my Lowes 20 foot pontoon boat and I did a great job I think after replacing the rotten wooden tansom wood piece that the motor connects to. Had about 4 guys in the neighborhood help me lift it out the back of my pickup truck and place it on the back of the pontoon boat and bolted her on snuugly. Anyway, to make a long story short I hooked all of the cables up and electrical wires up and cranked her over she seems to be running at 2,500 rpms until I go back to the engine and manually move the main throttlle plate that pushes on the roller for the three carbs back with my finger and she will idle down to about 1100 or 1200 rpms. I have adjusted the trunion nut on the throttle cable but am maxed out to shorten the cable to pull the throttle linkage back to get the motor to idle right. Basically what I did is use the remote control that was already in my pontoon boat that operated the 25 horsepower Johnson that was previously on it to operate the 70 horsepower and it did come with the remote with cables and wiring and I have that sitting in my garage floor. How can I fix this idle issue? Should I remove the throttle riding linkages and clean them up and see if there kinda binding up or what do you think? It seems to crank very easily and run great if I can get that idle to idle on its own without me having to manually get the idle down on her.
 

Big Bubba

Senior Chief Petty Officer
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Apr 11, 2007
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746
Re: 1983 Johnson 70 horsepower outboard idle?

OOPs! I forgot one more thing. I had this running with the muffs on and out of water and it idles at 2500 rpms and it will get down to 1200 rpms with my fingers.
 

5150abf

Vice Admiral
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Aug 12, 2007
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5,808
Re: 1983 Johnson 70 horsepower outboard idle?

the trunion is for fine adjustment you may need to use the adjustment on the throttle linkage, there should be a nylon clevis on the linkage before it gets to the carb, pull the cotter pin(super fun) and main pin and turn that which ever way you need to go, I would center the trunion first though so you have some fine adjustment to work with.

I would check timing when done too as the to systems are linked, if you change one you change the other.
 

Big Bubba

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Apr 11, 2007
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746
Re: 1983 Johnson 70 horsepower outboard idle?

Hello to you again,
Yes, after reading your reply I think my timing is way out and that is why it is idling high becuase when I went to move the timing adavance under the flywheel it sounded great and that is with the main throttle linkage away from the roller almost and 1/8 of an inch so I am thinking I need to lenghthen the rod to push the timing back some. Do you guys have a step by step copy of the procedure to do this so I can do it myself and save me some money. I will get a manual but I don't think I will get it in until week after next. My wife is driving me crazy to take her out on the pontoon boat I just bought and I want is to be right before I take her out and I am willing to do this work myself to save money. So if you can send me the procedure for adjusting the timing and the idle on her that would be great. Can you PM me with the info? Thanks again for your time and patience. You Guys ROCK!!!! on this site. Bob:)
 

Big Bubba

Senior Chief Petty Officer
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Apr 11, 2007
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746
Re: 1983 Johnson 70 horsepower outboard idle?

Hello to you again,
I forgot the procedure is for model# J70ELCTE which is a 1983 model year motor 70 horsepower. Can I get the procedure in pictures as many as you can get to make it as "Clear as Mud", LOL. Thanks Bob:)
 

Big Bubba

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Apr 11, 2007
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746
Re: 1983 Johnson 70 horsepower outboard idle?

O.K. guys I went out to my boat and tried to get this thing to idle on its own without any assist by me. Basically what it is doing is the timing isn't comming back for enough when I go forward with the throttle and come back. Me and my buddy adjusted the idle screw and the line on the master throttle plate to just touch the roller to advance the carb throttles on the three carbs. But the problem is the timing will not come back all the way and I thionk it is on that white peice that connects to the throttle plate. What can I do to fix the problem. I heard tha the piece that moves the timing advance forward and back has a spring within it. Let me know becuase my wife really wnats us to go out and I don't yet have a manual for this motor. Please help me out with step by step procedures to fix this. Is Joe Reeves out there tonight?
 

Big Bubba

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Apr 11, 2007
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746
Re: !!!UPDATE!!!1983 Johnson 70 horsepower outboard idle?

Re: !!!UPDATE!!!1983 Johnson 70 horsepower outboard idle?

Good afternoon everyone,
How are you this evening? I am doing better now that my motor is running somewhat btter now. Anyway what I did was remove the cables both shift and throttle and used my hands to check for binds in the linkages on the motor and they were free as can be and I also cehecked the cables and made sure they were not bound up by pushing the remote control forward and and reverse and they were not bound up. So what I did is started from scratch and redid everything. Basically I had to adjust the rod in between the main throttle plate that pushes on the small roller to give throttle to the 3 carbs and the timing advance under the flywheel. The individual that had the boat had the timing adavnced to far forward toward the front of the motor basically it was halfway between the up rubber stop and the opposite end. Basically in between full forward and full reverse travel. So what I did is adjusted the threaded rod end and moved the timing advance to the rear again. Then I put the motor in neutral and put the cables on by slip fitting them. Then I pushed the throttle on the remote control to full forward position and looked at the butterflies and they were exactly horizontal and aprallel across all 3 carbs and the timing adavnce under the flywheel was against the rubber up stop so that looked good. Then I moved the throttle back to neutral position and the carb butterflies were fully closed and the shift in neutral and the linkage was aginst the idle stop which it wasn't before. It was probably between 1/8 to 1/4 inch of a gap between the linkage and the idle stop in neutral position. Then I cranked the motor over with the water hooked up with the muffs and it is peeing great and it idled nicely about 1300 rpms in neutral. Then I pushed the throttle somewhat in forward and it reved up nicely and went into gear with a slight clicking noise and the propeller turned and then reverse same thing and nuetral but the proppeler turned slowly and I grabbed the propeller with my hand and it stopped with no problem so I guess that is normal in Neutral position. Then I reved it up with the warmup lever and it reved up nicely and returned to 1200 to 1300 rpms in neutral. The motor actaully ran up to 2500 rpms before I did the adjustments. What do you guys think. Am I good to go and did it right the idle timing adjustment that is? Thanks Bob
 

Big Bubba

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746
Re: 1983 Johnson 70 horsepower outboard idle?

Can someone help me out and let me know if I wil be good on my motor or not? Thanks Bob
 

Big Bubba

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746
Re: 1983 Johnson 70 horsepower outboard idle?

O.K., guys I filled a trash can full of water and the water line went past the cavitation plate on the lower leg unit. I raised the warmup lever about a good half of and inch but not all the way up and cranked the motor up very easily and let it run for at least 20 minutes tonight and she seems to be running good and running 1000 rpms in that trash can full of water. I also reved the engine up a little and she ran great and the thermostats did open a few times becuase warm water/mist came out of the 2 exhaust holes at the back of the motor a few times. After that I did remove the spark plugs and looked at them and I definietly need to replace them because the electrode is worn somewhat basically dished above the center electrode so I will replace those plugs since I have a brand new set QL77JC4 Champions already. What do you guys think am I all right and is the trash can full of water a good way to check it. Is the trash can method about the same as being in the water of a lake. Thanks again, Bob
 

reeldutch

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Feb 2, 2004
Messages
1,340
Re: 1983 Johnson 70 horsepower outboard idle?

its almost the same exept for that you cant put a load on it by putting it in gear.

i think you should be fine.

because you changed the timing you should verify it in the lake with a timing light.
check idle timing and wide open/maximum advance.
if your timing is not set correctly you will kill the motor.
after you are 100% sure its good paint all the settings.



as soon as you put it in gear it wil come from 1000 rpm in neutral to 700/800 in gear.

if your idle rpm where to high you might slowly kill your gears in the LU.
but 1000 rpm is no problem.
 

beeston86

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Joined
Nov 25, 2009
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Re: 1983 Johnson 70 horsepower outboard idle?

Hey, this is my first post...

Straight to the point, I went to look at a boat today with a Johnson 70 (Model E70TLCNB, 1983 I think) and the guy showed us it running using a trash can like 'Big Bubba' used above. However in his thread he said "warm water/mist came out of the 2 exhaust holes at the back of the motor a few times", on the motor in question water was gushing out of two holes approximately 1cm in diameter and 3cm apart at the top of the leg, I can only assume these are the "exhaust holes" described by 'Big Bubba'. These holes can be seen on the motor in this video "http://video.yahoo.com/watch/248161/1950220", however no water can be seen, I can only assume this is because the motor is not in the trash can but only been fed by a hose pipe.

My question is: What is the normal behaviour and am I describing the exhaust holes correctly. Also any ideas on the problem if this is not the case?
 

ezmobee

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Mar 26, 2007
Messages
23,767
Re: 1983 Johnson 70 horsepower outboard idle?

Welcome to iboats beeston86. It is best to start a new thread with your question instead of digging up and old one. The trash can versus muffs situation has nothing to do with your cooling. You've got a good pee stream so your water pump appears to be working. As I understand it, water won't start coming out of those exhaust relief holes until the thermostats open. So maybe you didn't run it long enough. Even so it really only spits out of those holes. I don't think you have a problem.
 

Fisher2061

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May 1, 2011
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Re: 1983 Johnson 70 horsepower outboard idle?

I know you had a couple friends help you lift your motor.What if you lift the motor yourself.Does anyone know where the lift point is on a 1998 70 hp Johnson.
Thanks for your HELP!!!!!
 
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