Outboard idling at 3000RPM

Ugh.

So I dewinterized my boat ('95 Stratos 261/'95 Johnson 90HP) last week, took it out, and it ran a little rough, but I chalked that up to old gas/blowing winter's crud out of the engine. Today when I started it up the engine would not go below 3000 RPM. I played with it for a few minutes, and decided that perhaps I shouldn't be messing with it on the hose at that RPM.

Any ideas what could be causing this or where to look into troubleshooting? I'm completely stumped.

Air leak? Hose disconnected?

First thing to check is the carb and timing linkage to make sure it's not binding and holding the throttle open. Old fuel may have gummed up the throttle shafts making them stick open a bit. Take the airbox/silencer off the front of the carbs and have a look inside. See if the throttle plates are fully closed. If the throttle plates are open some, disconnect the throttle cable to see if it's binding. Good call not to run it at that RPM on the hose. Garden hoses won't deliver the water flow needed at higher RPM's. Also, running an outboard at high RPM's unloaded can damage the motor, not to mention the possibility of run-away.
Report your findings in this thread.
KB

KB,

Thank you very much for the response. I have a SELOC manual, but am not sure what the timing linkages/throttle shafts/throttle plates look like. I'm thinking that the diagnostic work you described might be a bit beyond my skills.

I had the throttle cables replaced in November right before I winterized it - I'm wondering if this issue could be the result of a crappy repair job?

Thanks again for your advice!

Andy

The airbox/silencer in the plastic unit on the front of the carbs. It is held on with 4 rubber straps. Pull the rubber straps out of the notches they are in and remove the airbox. The airbox will have 2 hoses attached to it. They just pull off. Take a flashlight and look into the throat of the carb. Inside each carb you will see a round plate. Check to make sure it is closed with no gaps around the edges.
Look in your manual under "synchronization and timing" for a rundown on the linkage and cable connections. Disconnecting the throttle cable is easy. IIRC you remove the nut holding the cable end to the linkage, then remove the bolt holding the cable jacket and rotate the cable upward so it clears the linkage. Easy-peasy.
I don't have the manual in front of me so I may be off some, but I have the manual at work and would be happy to bring it home and help you diagnose the issue if you are game.
ETA –– Disconnecting the throttle cable will isolate whether the cable is at fault or something else. Being as the cable was replaced recently, they may have not adjusted it properly. This is easy to correct. The throttle cable should "hold" the throttle shut when in the idle position. We call this "preload" on the cable. The tech may have not gotten enough preload on the cable. Therefore the cable cannot return the linkage to the idle position. You by chance don't have the warm up lever up do you?

That's what i was going to ask too...

Always best to check the simple things first.

Im not sure what the warm up lever is. Is this a piece on the throttle or actually in the engine itself?

On mine it's a little lever on the controller

My throttle control is this model, so I'm thinking that I don't have one:
http://www.marinepartssource.com/partdetails.asp?pnumber=OMC176917&cat=15&catname=Controls&sub1=1&sub2=2&sub3=0&subcategory=Control%20Heads&subcategory2=Side%20Mount&subcategory3=&mfgno=OMC176917

Nope, yours doesn't have the typical warm up lever. That one, you push the button in the middle of the control handle pivot for throttle only. I have the service manuals home with me if you want to try to troubleshoot it. There were two different 90hp motors that year. The 90 degree vee uses aluminum carburetors and the 60 degree version uses plastic carbs. Which one do you have?

I'll snap some photos tomorrow morning, but its model JTLEO90 if that helps determine which carburetors it has.

I snapped some photos this morning - the carburetor is the piece I've labeled "A" in the top photo, correct?

Yeah, the carbs are behind the plastic plate

Thats a 90 degree V-4 with aluminum carbs....whew... The 60 degree engines with the plastic carbs can be troublesome. Let me annotate a photo and show you where the linkage etc.. is. The linkage looks like it's out of whack from the last pic.
Wait one while I gussy up the pic..
Ok, first thing to look at is the idle adjustment screw, particularly if it is seated against the "stop" on the engine block. Don't attempt to adjust it, just verify it's against the stop. If it's not against the stop, disconnect the throttle cable from the linkage. You need to remove the nut/washer on the end, then remove the bolt/s on the retainer, remove cable. At this point, see if you can move the linkage where the cable connects towards the front of the motor (idle position).

Report your findings..
KB
ETA –– One note of caution. If you want to run the engine with the throttle cable disconnected, re-install the cable retainer to hold the shift cable. Bungee the throttle linkage forward in the idle position. Outboard throttles won't return to idle by themselves.

I had a chance to go take a look at the motor today. It appears that the issue is the idle adjustment screw is not seated against the "stop". With the engine off, I put it into forward, reverse, then neutral forward and reverse and at no point did the screw contact the stop:



KB, I wasn't 100% sure what you're instructions were in the previous post, so I took some pictures for clarification:



My understanding is that I should remove the two nuts on the right side that I've circled in red, then the two nuts on the left that I've circled in red, and adjust levers "A" and "B" until the adjustment screw contacts the stop?

While I was in there I took the cover off and had a look at the inside of the carburetor, which looked fine:




KB (and everyone else who has posted in the thread) once again, thanks for your assistance. Its much appreciated.

You don't need to remove both cables. Cable "B" is the throttle cable. Remove the top bolt on the right, loosen the bottom one and pivot the retainer to free the cable adjustment thumbwheel. Remove the nut to the left on cable "B" and remove cable end from linkage. Pull linkage towards the front of the motor and adjust thumbwheel on cable to line up with the linkage that is now pulled forward. You want to adjust the thumbwheel so it is slightly "pulling" on the linkage when it is hooked back up. This is the "preload" I mentioned earlier. This preload ensures the throttle returns to the idle position. Re-install the nut and the cable retainer and test function with engine off.
ETA –– It looks like the "cam" is dry. Smear a light coat of grease into the curved slot in the cam where the "cam follower" rides. Also, you will notice a small arrow/triangle embossed into the cam. This is where the cam follower should be when it is in the idle position.

Thanks for the clarification - one last question before I attempt this tomorrow.



The triangle for the idle position should be towards the side of the cam labeled #1 in the picture below (as opposed to the side I've labeled #2)?

Correct..position 1
ETA–– when you have the cable removed, work the throttle linkage and see how it works. The cam,follower, carb linkage roller, timing arm etc. You will see why all this linkage needs to be "just right" to function.

I think I got this reset properly.  I adjusted the throttle cable until the idle screw touched the stop plate (when the throttle arm is in the idle position).  Pics below:





I tested it out with the engine off, and everything seemed to work properly.  Think it looks okay to hook up to the hose tonight and turn on?

Yup, ready to test. Good job! Cam still looks dry...needs some grease in the cam slot..

Success!

Well, partial success anyway.

I started it up on the hose last night and indeed the high RPM idling was gone - it first idled at about 1150, then settled at ~1000 after a few minutes. It shifted into forward fine, however, the weirdest thing happened when I tried to test it in reverse. It shifted into reverse without a problem, but at about 130 degrees (assuming full forward throttle is zero and full reverse is 180) it felt as though something was sticking in the throttle control arm. Then when I shifted out of reverse into neutral the propeller continued spinning in reverse until I edged it forward a touch.

Any ideas what could cause this? I'm going to try and take apart the control arm to see if there's some crap in there this weekend I think.

Sounds like the shift cable is out of whack now. Same procedure as the throttle cable. Place control handle in neutral, disconnect the shift cable this time from it's linkage, operate the shift linkage on the engine to assure it's in neutral, adjust thumbwheel until cable lines up with stud on linkage. The shift cable should have NO preload on it. After you disconnect the cable from the linkage, pull and push the cable in and out of the jacket to get an idea of how much "freeplay" there is in the cable itself. You want to adjust the cable so it fits the linkage in the "middle" of the freeplay..(if that makes sence). Also, too much preload on the throttle cable will make it hard to shift, but it sounds like yours is just shift cable out of adjustment and not centered in the "freeplay".
KB
ETA–– Those engines had a feature called "Quick Start". It raises the idle rpm when first started and then will return to normal in a few seconds. This is all done electronically, nothing to adjust, nothing wrong either.
ETA2–– The sticking you refer to is the throttle cable trying to actuate the shift linkage when it's already at full travel. Cable adjustment will cure this.

A couple of questions. Just so I'm don't start adjusting the wrong cable, the shift cable is cable "A" in this picture:



I'm not sure I'm 100% clear on what preload and freeplay are (and therefor how toI should remove/adjust them in the shift cable). Freeplay is the looseness between the black outer sheath and the golden inner shift/throttle cables right? So I should figure out how much freeplay there is in the throttle cable and try to attach it to the linkage at about half tension?

Then preload is the tension on the linkage - with the throttle cable, I wanted some preload so that it would be in the correct position to start. With the shifter cable, you said I want no preload - how can I tell if its preloaded? Is there an indicator (like the white triangle on the throttle linkage) to indicate the appropriate neutral position?

Cable "A" is the shift cable. What I mean by freeplay (slack) is when you have the cable disconnected, you will be able to move the black cable end (where it hooks to the linkage) in and out a little (over the brass cable sheath). Say it has 1/4 inch of freeplay. When you adjust the thumbwheel, adjust it so when it lines up with the linkage, there is 1/8 inch freeplay to either side of the linkage stud. The goal is to have equal travel between forward and reverse gears so you need to compensate for the cable freeplay. It's hard to put into words...I could show you in 5 minutes if I were there...

I played with it for a while and you're diagnosis is spot on - with the cable disconnected, the throttle lever will move the disconnected end of the cable all the way in and out without any resistance. However, I'm definitely struggling with getting this set back up correctly and as it sits now I've definitely made it worse as I the throttle lever will no longer go into forward or reverse.

It almost seems as though when I hook the cable up to the linkage, the cable is pushing through the linkage at an incorrect angle (and causing resistance). Could that be the problem?

Sometimes it is necessary to spin the prop a little to get the shifter engaged. It is designed to be shifted with the engine running so the teeth on the "clutch dog" (sliding clutch) in the gearcase will mesh. You didn't get the cables reversed did you? Try disconnecting the shift cable again and try shifting the linkage on the engine while turning the prop with your foot. MAKE DAMN SURE THE ENGINE WON'T START when you try this. I like to remove the spark plugs to ensure I keep all 10 toes. Shift the linkage into FWD/NEU/REV while spinning prop. When it goes into FWD or REV, it will lock up and try to turn the engine. This verifies it is in gear. Find neutral and verify by spinning the prop. It should turn freely. Then put the control handle in neutral and adjust cable thumbwheel to match the linkage.
ETA––pics inbound
ETA––-2

It works!

For the last two weeks, its either rained, or I've been out of town, so I haven't had a chance to play with it. I went down and fiddled with it this morning. After trying the instructions from SELOC several times with no luck, I had the thought that since my issue is with shifting into reverse, maybe I should try the SELOC instructions using the full-reverse setting instead of the full-forward setting and it worked perfectly the first time.

Assuming the weather holds, I'm going to test it out on the Potomac tomorrow afternoon.

KB and everyone else who contributed to helping me with this repair job, thanks so much for your assistance! Will update this thread again tomorrow, hopefully with massive bass pictures as well!

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