!976 Johnson 9.9 wont run

[Red Dog23]

hello there,i have a 1976 model 10r76 9.9 johnson outboard.It has very low hours on it and I have never had any problems with it until this year.It had been sitting all winter here in upstate New York in my garage.First time out this year I noticed that it would start to bog down when I gave it full throttle...like it was dropping one cylinder,but it would run o.k. low to mid throttle.I started with half a tank of last years gas and topped it off with fresh gas before the first start.went to use the motor again aprox one week later and it would not start at the dock.I changed the plugs and it still would not start.I pulled the air cover off and sprayed a small amount of carb cleaner in the carb and it started up.I had a hose hooked to it and let it run at a slighty higher speed then idle for aprox 3 mins.When I lowered the idle with the control handle I noticed that it sounded like it was dropping a cylinder.It then stalled out like it was starving for gas..because the idle would pick back up slightly if I choked it for a second.When I first started checking this out I noticed one plug was wetter then the other.This engine has always run great and this problem has me miffed.Thanks for any help....Red Dog

 

[jim dozier]

Re: !976 Johnson 9.9 wont run

Pull the plugs one at a time while its running and isolate the cylinder that is not firing. Start checking your ignition components. Run it in the dark and look for arcing. Put in new spark plugs if you haven't already. Pull the plugs and verify that you do or don't have strong blue spark on both plugs.<br /><br />If you got a good spark on both cylinders, you probably need to remove and clean/rebuild (completely) your carbs, you're due.

 

[Red Dog23]

Re: !976 Johnson 9.9 wont run

Thanks for the tips...seems like spark is good.ironically I tryed to start it before I did anything ...and the thing started.I needed to choke it several times while it was running to keep it running.Is there any kind of fuel add that you would rec putting in before I take the carb off?....its beginning to look like the carb is just dirty.......thanks again!

 

[jim dozier]

Re: !976 Johnson 9.9 wont run

You have all the symtoms of a carb in need of a complete rebuild. There isn't anything you can put in the gas or spray on the carb that will do anything. Remove the carb, disassemble it completely, visualize the jets, soak them overnight in a can of carb cleaner, replace the float valve and reset the adjustment height of the float. Note the number of turns to screw in the idle screw till it gently stops, then remove the idle screw and when you re-install it, open it to the number of turns from all the way in. Adjust the screw for best idle then open it another 1/4 turn.

 

[Red Dog23]

Re: !976 Johnson 9.9 wont run

Thanks Jim D...I think you hit the nail on the head.I would not have gotten this far without your help...again,thank you very much for your expertise..Red Dog

 

[Solittle]

Re: !976 Johnson 9.9 wont run

Red Dog - When you have the carb cleaned and disassembled take it to someone who has a high pressure air compressor if you don't have one and blow out all passages. Crud gets to where you can't see it & the air will get it out.

 

[Red Dog23]

Re: !976 Johnson 9.9 wont run

To all who have helped...thank you much!..I rebuilt the carb last night (cost 14$).she runs like new again.I picked up the kit at a local johnson dealer and it came with all the needed parts..for a complete overhaul.There was quite a bit of crud in the bowl and the needle and seat looked pretty tired as well as the float.The whole job was not nearly as bad as i thought it would be.........again thank you,you guys are great!