75' 70 Johnson looper " Wont idle speed "

[george_sciacca]

I purchased this motor sitting for 5 years.It was running when stored.carbs are clean as new previous owner well taken care of.Installed new water pump kit and fuel pump,set of plugs.Motor will idle in nuetral but dies and I have to choke to resart even when hot,in gear at idle does the same loads plugs till you clean out at wot.Half throttle to W/O runs great.Never been rebuilt gonna take a compression test next.Any thoughts? Great discussion on the difference between loopers and cross flows.Thats why i like comming here. thanks, george

 

[Cricket Too]

Re: 75' 70 Johnson looper " Wont idle speed "

george....How do you know the carbs are clean as new? Even if they look good on the outside they could be a mess on the inside. After 5 years I would not hesitate to pull them off and tear them down, those carbs are simple and easy to rebuild. Also are you running good gas or 5 year old gas? Either way you should rebuild those carbs and it will probably start running alot better. Good Luck.

 

[Solittle]

Re: 75' 70 Johnson looper " Wont idle speed "

http://www.outboardrepairs.com/carburetors/

 

[jim dozier]

Re: 75' 70 Johnson looper " Wont idle speed "

What makes you think it loads the plugs? Did you remove them and find them fouled? The other part of your history/description suggests a too lean idle circuit which is consistent with a dirty carb that has been sitting for 5 years. You might be able to help it by enrichening the idle mixture screw if it has one but you might have to clean and rebuild the carbs. I'm with mmcpeck on this one, after 5 years crud can get in the jets and the gaskets may have dried and are leaking air. Carbs are not in a beauty contest for the outside, its the orifice that counts. Also check the fuel lines for cracks and leaks at all connections and junctions. You may be sucking air somewhere.

 

[george_sciacca]

Re: 75' 70 Johnson looper " Wont idle speed "

I pulled the carbs off and they were very clean inside no goop and such like the gas was run out and drained.I dissasembled them and sprayed carb cleaner in them and let them soak over night.BUT- Tuesday I put in another set of new plugs and noticed that the four top bolts in the crankcase halfs were missing,gone, not even in the botom of the housing,so went and bought four more and installed them but havent had a chance to run it yet.That would cause it to run lean if the crankcase was sucking air in wouldnt it? Not run rich.that was the color of the plugs i took out,oil fouled.I mix at 50:1 3oz. to a gallon and i run 93 octane.any input from the forum would be greatly appreciated... george

 

[Solittle]

Re: 75' 70 Johnson looper " Wont idle speed "

Stick with the 87 octane that the motor was designed for.

 

[Cricket Too]

Re: 75' 70 Johnson looper " Wont idle speed "

george....I would deffinetely think that those missing bolts would cause this motor to pull air and run lean, good thing you replaced them. Even so I think you should replace those carb gaskets as jimd said, they could be dry, especially if the carbs were run dry before storage for 5 years, and then if you re-used them they could be sealing even worse. A gasket set is cheap and easy and then you can adjust the idle circuit from there. Good Luck.

 

[george_sciacca]

Re: 75' 70 Johnson looper " Wont idle speed "

Thanks to all that replyed,Ive taken friday off just to play with it and have a decent shopping list.I'm gonna go with the rebuild kits for the carbs. Also the center carb inlet for the fuel line was leakin real bad (O-rings I recon)when ya pump the bulb,its got new fuel lines on it but I used zips and leaks some from those too.Ive only ran it 2wice on the water since I got it so its gonna get a good going over.Thanks again to all.George