Multiple problems

[TNfishing]

Have a 1983 70hp Johnson Seahorse. Ran great when I bought the boat. There seems to be a linkage problem on the motor. Took in out, idles great then dies when put in forward or reverse. Checked the fuel tank and adjusted the idle linkage. The attached pictures will show the part I am not quite sure of. Is this spring loaded? Is it supposed to engage/advance the linkage on the carb? It stays in whatever position I manually put it in and doesnt release back. Trying to find a manual on this motor....but no luck. Any help/advice appreciated. Can upload more pics if needed. Thanks in advance !!

 

[jtexas]

Re: Multiple problems

ok, I marked the part that is disconnected. The other pic I believe might be a later model that yours, but see if it doesn't help.

you can view schematics of your motor at www.shop.evinrude.com click on "electronic parts catalogue" select "johnson" in the drop-down box at the top, drill down to your year/hp/model #.

factory shop manuals are available at kencook.com or marineengine.com

 

[TNfishing]

Re: Multiple problems

thanks jtexas.....this pic shows where you have circled the part that is disconnected. What is this part that it hooks to? It seems to be frozen and will not return to correct position. Let me know if I need to submit more pics.
Thanks in advance

 

[patrick4266]

Re: Multiple problems

It looks like some one made that arm. Might be your problem. I have the manual for that. On that year they don't make a 70hp manual by it's self, it includes all kinds of other hp's. It cost me 78 bucks from ken cook.

 

[ezeke]

Re: Multiple problems

Here's a 1981 someone posted - it's probably what it should look like: http://forums.iboats.com/attachment.php?attachmentid=52832&d=1273726026

Parts diagram here: http://www.boats.net/images/diagrams/brp/IMAGES/393586/20.png

 

[jtexas]

Re: Multiple problems

It does look like a self-engineered part. Been like this since you got it?

You said "ran great when I bought the boat" -- Did you test it on the water, or on the trailer?


Are you saying the circled part won't move? that's the throttle cable.

I believe it attaches here....

 

[TNfishing]

Re: Multiple problems

Ran it on the water for 20 to 30 minutes before we bought it. Just dont know the function of the arm ( would be part # 51 on diagram ) . Does the spring behind the arm suppose to return the arm back to a neutral position? It sticks and is hard to move either backwards or forwards. The motor (parts and all ) were like this when we bought it....and it ran great. The guy said he had replaced the bottom end .....he let it freeze last winter. Put the muffs on it and attach water hose and it starts and runs great. Put in water and can idle around but would never gain any speed. Just cant figure it out. The "arm" doesnt move and doesnt allow the carb linkage to engage. I can move the throttle cable in and out when disconnected from the "arm" piece. When connected...it wont move........Thanks in advance.

 

[jtexas]

Re: Multiple problems

#51 ("throttle lever") is moved by the throttle cable, the circled part pictured above.

#43 ("spark advance lever") is also moved when the throttle control is advanced, but it does not travel as far; the spring moves the spark lever and holds it in fully advanced position until the throttle is lowered back down.

A couple pics of my '79, all those part numbers are the same...
Here you can see where the throttle cable is connected to the throttle lever, with the control in the neutral position:

And here it is with the throttle control fully advanced:

 

[jtexas]

Re: Multiple problems

With the throttle control all the way forward, cable should line up with the lever to let you reconnect.

 

[TNfishing]

Re: Multiple problems

Ok...had carbs rebuilt, changed plugs and mechanic changed the "home made'" linkage back to original. Took to water this morning and when I put it in forward...it went in reverse. Reverse went forward. Cant see how or where the linkage could have been reversed. Has OMC shifter. See the before and after pictures. Any suggestions / help??? thanks in advance

 

[ezeke]

Re: Multiple problems

You probably have a 1970s hydraulically assisted mechanical gearcase on there which shifts the reverse of the strictly mechanical gearcase. You will need to either find the older shift linkage for the engine, find the correct gearcase, or put it back the way it was.

 

[jtexas]

Re: Multiple problems

What kind of mechanic did you take it to, that would let it out his shop with the shift control working backwards?

when you move the throttle/shift control forward, which direction does the shift lever go (see below).

was that 3rd pic taken in neutral? here's another problem -- see the part I circled in red...it looks like your throttle cam is butted up against the roller.

Comparing your 2nd pic with the 3rd, Looks like you moved the yoke out to the end of the rod. That's not going to work. When you get a load on the engine, the throttle valves are going to open too soon, before the spark timing is advanced. The motor is going to die when you try to accelerate.