Ever had this problem... need input please...

ritamigo

Seaman
Joined
Mar 16, 2012
Messages
62
My 70hp johnson outboard had serviced, carb rebuild, plugs, fuel filter, gas lines, timing, water impeller and ran great. Then after about 4 months it started studdering at around 1200 to 1600 rpm but not WOT or higher RPM. However I found out that if I tilt it up the studdering goes away gradually. Miller's Marine said it could be a stuck carb float. Any input would be greatly appreciated. Other wise it seems to run great. Someone suggested a bad propeller?

Thanks for any help.

JoeVee
 

EddiePetty

Lieutenant Junior Grade
Joined
Aug 25, 2008
Messages
1,008
Re: Ever had this problem... need input please...

I noticed in your list of serviced items that the fuel pump was not mentioned.

A couple of thoughts come to mind (especially since your problem is just over idle).

First would be a less than perfect fuel pump followed closely by a restricted transition port in the carburetor. A slightly sticking float needle would also be suspect.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: Ever had this problem... need input please...

Its a flooding carb as when you tilt you change the float level. Look for a swollen needle and seat from ethanol, debris in seat from fuel line degrading internally or fuel pump diaphragm flaking
 
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