reving 120

[wolflb2]

I have an 86 johnson 120hp that is running strangely. It revs up for a half second stops almost dies and then revs again. Could this be a bad power pack?

 

[The Marine Doctor]

Re: reving 120

Ignition Kicks when it cuts back in.<br /><br />Fuel just speeds up and down.<br /><br />There is quite a difference.<br /><br />I would suspect air is getting in somewhere.<br /><br />TMD

 

[wolflb2]

Re: reving 120

I'm poor mechanicly and tend to break more than I fix. I'm going to guess that the pressure in the fuel bulb would not change if there was an air leak cause the drop would be too small or the engine would just die?<br /><br />What do I look for to find the air leak?

 

[walleye052974]

Re: reving 120

check every where there is a mating suface after carb. and at every fuel line connection. i spray carb cleaner (the cheap aerosol stuff) at all susected points. if it trys to die you have a leak.

 

[wolflb2]

Re: reving 120

Thanks! Its running now.

 

[93bronco]

Re: reving 120

so what did you do to correct the problem???

 

[wolflb2]

Re: reving 120

This started with the engine not running as smoothly on the water as I thought it should and then after it sat for a few days I replaced a plug wire that had poor continuity. Motor started sounded good for about ten seconds and then started the reving/dieing.<br /><br />I stuck to the easy stuff (I break things). The tips were fuel related and I was low on fuel so I tipped the boat so that the back was lower than the front, added gas and switched out the fuel line from the tank to the engine since I had one around. The engine sounded a little different so I let it run and it worked it's way out after a minute. <br />I suspect I had some bad gas as well or it should have taken off right away.<br /><br />Now I have rough running in a window of 1000-2200 RPM. I'm betting on carb problem (dirty?)