1976 Johnson 85 HP Idling out of control

When I start my engine it runs OK at first then after about 2 or 3 minutes it starts idling way to fast and keeps getting faster.

What can I do to fix this?

Help I want to ride my boat this year

Re: 1976 Johnson 85 HP Idling out of control

Model number would help! Have you checked all connections and made sure carb/s are tight? welcome to iboats and post back.

Re: 1976 Johnson 85 HP Idling out of control

Engine number 85EL76G Carbs are tight

Re: 1976 Johnson 85 HP Idling out of control

When idling, the carb butterflys should be closed. You will have to pull the airbox cover to confirm that they are both completely closed when the throttle handle is in neutral. If they are cracked open slightly, you will get rpm rise. The idle on that engine is determined by the idle timing, not by the carbs. To lower the idle, you must retard the timing. Unscrew the large screw head on the spark advance lever. Make sure the throttle linkage is not binding-disconnect the throttle cable at the engine end when setting the idle. It should idle between 650-750 rpm: set when the boat is floating in the water and is in forward gear. It is normal for the idle to rise significantly if idling on the trailer.

Re: 1976 Johnson 85 HP Idling out of control

1) Where is the spark advance lever

2) What would the settings be if adjusted on trailor. I would rather not go to the water until I know it won't breakdown on me.

3) Separate subject what does the power pack do and what sort of indications would you get if it were malfunctioning? I have been trying to find info online about this but no luck so far.

Re: 1976 Johnson 85 HP Idling out of control

You can see the factory parts breakdowns for your engine at: epc.brp.com. That will help you with the nomenclature of the parts, including the spark advance lever. You can't accurately adjust the idle on the trailer. You have to float the boat. The engine must overcome the pressure of the water 24" down, so you need to have the engine deep in the water to get idle set correctly. Also, it must be loaded (in gear) so that it will run correctly when you are on the water. You can find some great ignition troubleshooting at CDI.com. They have some detailed test/troubleshooting procedures which will apply to your engine. If you plan to continue to work on your engine, the best bet is an original factory service manual from the original publisher: outboardbooks.com