1976 johnson 115 hp

[old_johnson]

I have this old johnson 115 from 1976 and just runs horrible. I have to get it started and slam it into gear in order for it to stay running and then it wont stay running at high speeds. It will bog and then if u choke it it will pick back up and then bog again until you let off the choke(and the cycle continues). I have gone through the carbs, coils, sync and link, adjustment of throttle and it isnt any of these things. So i pulled the carbs off and took the reeds out, they are rusty and some are a little bent. Could this be the problem?

 

[Fl_Richard]

Re: 1976 johnson 115 hp

Yup! They need to seal properly. By bent do mean not closing completely or literally bent?

 

[old_johnson]

Re: 1976 johnson 115 hp

yeah some were actually bent. how do they seal do they move? I bought a new reed plate with the reeds in it and just popped it in there. I dont actually know how they work.

 

[emdsapmgr]

Re: 1976 johnson 115 hp

It is common for reeds to not lay absolutely flat on the cage. Usually an engine will run fine in this condition. True bent reeds will result in crankcase compression spitting back through the carb throats on each compression stroke. Like a backfire when running. A bent or missing reed petal will cause this.

 

[Fl_Richard]

Re: 1976 johnson 115 hp

They are like a one way valve. When the engine draws mixed air/fuel they open, crankcase pressure closes them until the next stroke.

If they are bent and rusty they will not seal properly causing all kinds of problems depending on the severity of reed damage.

 

[old_johnson]

Re: 1976 johnson 115 hp

hmmm well i guess i just need to wait for the weather to get warmer up here in new york to see if i fixed it. thanks for all of the help guys