need help 120 hp johnson

[marine97]

I have a 120 johnson and with the muffs on it runs fine put it in the water and go to run it it boggs then stalls. Please help

 

[Dhadley]

Re: need help 120 hp johnson

Welcome!

That's not much background but it sounds like it may have been sitting for a while and the carbs need a bath. It has to do with backpressure in the exhaust. It will idle fairly high out of the water so if you adjust it out of the water it will probably be way too low in the water.

 

[marine97]

Re: need help 120 hp johnson

That is all I know about it. so you say the carbs is there anything else I can check to make sure I am mechanicly inclined and am sure with the finger pointed in right area this can be fixed. It is for my father when I go to visit in a month.

 

[Dhadley]

Re: need help 120 hp johnson

If it's been sitting with untreated fuel in the carbs for any length of time (over 45 days or so) then it's a pretty good place to start. Generally speaking if you even think the carbs need cleaning, it's a good time to do so. A dirty or partially plugged carb can make a mess out of a piston quickly.

 

[marine97]

Re: need help 120 hp johnson

Is this something I can do or need to find a shop I have rebuilt many on mowers and cars. Thanks for your help.

 

[Dhadley]

Re: need help 120 hp johnson

The carbs are pretty easy to remove, clean and reinstall. The linkage can be a little bit perplexing but if you have an OE service manual I wouldn't think it'd be too hard to do. If it were me I'd get a good OE manual and read it thru and then decide.