1976 Johnson 85 HP Idles too fast and slams in gear?

[nsejaw]

New to outboards; just bought a boat with 1976 85 HP that starts and runs beautifully, but idles too fast at the ramp and slams in to gear (forward and reverse) making it impossible to control at low speeds. I've read various threads...is this a simple adjustment at the controls or motor? A carb issue? Any help will be much appreciated. Thanks,

Jim

 

[Joe Reeves]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

Look at the vertical throttle arm that leads from the throttle cable up to the timer base under the flywheel. Approximately half way up that arm is a mechanical idle set screw, back it away from the block temporarily.

Now, loosed the clamp that retains the throttle cable to the engine and adjust the threaded trunion so that it retards the vertical throttle arm to the idle desired.

The above will solve the problem "IF" everything else (carb linkages, sync, etc) is as it should be.

 

[stylesabu]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

everything is simple when you know what to do. sounds like throttle plates are staying open a little. do you have a working tach on the boat? it could be throtl cable adjustment . cable it self could be worn or binding, idle screw out of adjustment. fast idle sticking, choke soliniod. many thgings could cause b this, shouldn't be to hard to fix. but don't continue to operate this way as it will damage the clutch dog in lower unit. 1st get to carbs and linkage. it will help to removeairbox on carbs so you can see throtlle plates they should be closed. then pop linkage off throttle cable,did this cause plates to close? you can do this on muffs in drive way, if close to water ,thats better. but you need to find whats causing plate to hang open. if this lower idle, disconnecting throttle cable from card linkage then its a cable adjustment. hope this help, need more info on what to do if it doesn't help

 

[JSGOLD]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

Just a thought here....I have a 55HP evinrude, same year as yours, and it has a warm up handle on the control. It will idle fast until warmed up then you shove it down and idle drops to normal. Maybe your control is a problem? What kind is it?

 

[nsejaw]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

Mine has the same controls with the 'warm up' lever which I use for cold starts and then depress when the engine starts; honestly I haven't noticed if it drops the idle; we've only had the boat 1 week, and out to lake twice. Ah, the fun of old boats. Right after I bought it the steering arm froze in the engine mount (4 hrs with a hammer and steel rods to get it out). And yesterday we took it out and lost the prop right off the ramp (I don't know if the cotter pin was missing or if it sheared off from the way it jams into reverse)! Got the prop replaced and now I'm just afraid we'll lose another or ruin the clutch if we don't get the idle adjusted.

Thanks for everyone's post! I've ordered a manual for this motor and will get it tubbed and play around with it...

 

[JSGOLD]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

It should drop some. Mine kind of "jerks" when it goes into gear too....But nothing bad. It will idle faster out of the water FYI, don't adjust it down too much or it won't idle in the water very well. I don't run the 55 often as we use it in <10hp lakes 90% of the time, but the warm up lever shouldn't let you shift if in the up position. And if the idle does not drop I suspect your linkage or shifter is off then. If you disasemble that control box read the manual carefully. There is a certain order it goes back together in or it will drive you crazy. I replaced the ignition switch in mine and lubed it up last year, tried to assemble it on my own without reading it. Bad idea!

 

[nsejaw]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

Hmmm...when we replaced the prop, we obviously did not have the original to compare (bottom of lake) so a 13 3/4 X 15 was found that fit okay; but researching posts, it seems a 13 1/4 X 17P was common for this motor. Could this be effecting idle speed?

 

[boobie]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

No , back up and read what was already suggested. There's some good knowledge up there.

 

[stylesabu]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

you need to get that idle figured out.don't open that control box without a manual and a camera.there should be any need to open it adjustments can be made from outside up at motor. things rarely "go out of adjustment" unless someone screws with it. i would look for something hanging up or not working correctly. and you still need to know rpm,to know how fast is "too fast"

 

[laotou]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

This thread talked about the warm-up lever.

http://forums.iboats.com/showthread.php?t=521155

My engine is 76 Johnson 85HP. When the warm-up lever is down, the speed changes from 4000 rpm to 1200 rpm which is still "too fast".

 

[nsejaw]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

I have found the problem....but how to fix? I can manually move the plate at the motor as shown in photo 1; but if the warm up lever is raised, it move it to fast idle position (photo 2), but will not move the plate back into original position when depressed ( I can only do this manually); So I assume it is a connection problem with the throttle cable, but how should I proceed? Thanks,
Jim

 

[stylesabu]

Re: 1976 Johnson 85 HP Idles too fast and slams in gear?

ok i think i understand what you are talking about,you will need 2 people 1 to move controls and you to watch carbs and linkage. it almost sounds like you fast idle cable is broken inside.it pushes it open for fast idle,but when you push it down for idle it should move,if cable doesn't move both ways. find out why