I cannot begin to tell you all the frustration I have had tryingto resolve this lean spit at idle on my 98 175 ocean pro outboard. I have rebuilt everything, Carbs, fuel pumps, replaced hoses, and replaced gaskets. For 4 yearsI have been dealing with it coming and going. And just by chance I found the problem!
It was an o-ring in the feed line at the bottom of the VST. See picture. Item #’s 63 and 65
I had decided to just replace this hose, and while I was atit I saw the 2 o rings and decided that if I was going to replace them with new hose and clamps, I might as well replace those as well. So I ordered them. Upon removal…. I fin the issue...See Pic 2.
Yep crushed o-ring…. SOB1. Now here it real problem. The O-ring makes the nipple too big for the hole .when it is inserted to into the bottom of the vst. When you try to insert it,it requires a hell of allot of force and the o-ring slips and gets pinched. t I simply too thick. Plus the bottom o ring crates a air gap because it only screws from one side it does not have even pressure. So if the top o ring has a hole from getting pinched and the bottom o ring is not sealed correctly…you get air intoyour mixture resulting in a lean spit at idle. This is a design flaw for sure.
Now here how I fixed it. Take the whole nipple to yourlocal auto parts store and get a fuel resistant o-ring that fits. Cost me 15cents at autozone. DON’T USE the bottom o ring it does not seal even anyway and the top onewill seal fine. This resolved my lean spit at idle. No spitting no popping /stalling for a whole season...yah!.
It was an o-ring in the feed line at the bottom of the VST. See picture. Item #’s 63 and 65
I had decided to just replace this hose, and while I was atit I saw the 2 o rings and decided that if I was going to replace them with new hose and clamps, I might as well replace those as well. So I ordered them. Upon removal…. I fin the issue...See Pic 2.
Yep crushed o-ring…. SOB1. Now here it real problem. The O-ring makes the nipple too big for the hole .when it is inserted to into the bottom of the vst. When you try to insert it,it requires a hell of allot of force and the o-ring slips and gets pinched. t I simply too thick. Plus the bottom o ring crates a air gap because it only screws from one side it does not have even pressure. So if the top o ring has a hole from getting pinched and the bottom o ring is not sealed correctly…you get air intoyour mixture resulting in a lean spit at idle. This is a design flaw for sure.
Now here how I fixed it. Take the whole nipple to yourlocal auto parts store and get a fuel resistant o-ring that fits. Cost me 15cents at autozone. DON’T USE the bottom o ring it does not seal even anyway and the top onewill seal fine. This resolved my lean spit at idle. No spitting no popping /stalling for a whole season...yah!.
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