Sputtering Johnson V4 90hp - 1994

[Berdink]

I have a new to me 1994 Johnson 90hp V4.
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It started real nice and ran real nice when I first heard it run.
When I ran it more at home, it sputtered some off and on.
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I did a strong mix of seafoam to see if that would clear things up.
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It didn't.
I read up on the Link & Sync and got everything adjusted as described.
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But then it progressively sputters more.
It's been awhile since I've worked on engines. My last was a SBC in a 1965 C10.
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Anyway, I remembered the idea to spray carb cleaner around gaskets and linkage and hoses.
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When I spray carb cleaner at the bottom of the upper carburetor, it so slows the idle and smooths out. (see pic) - btw, I was pleased to see I had aluminum fuel bowls and not the plastic ones.
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This tells me I have an air leak.
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I'm going to order a carb rebuild kit and gaskets, but it may just be a leak. I figured if it wasn't just a leak, then I'd still know that I went through the carbs and that at least is good.
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Thoughts?

 

[Berdink]

This kit x2, correct?

 

[racerone]

I doubt there is an air leak.

 

[Berdink]

I doubt there is an air leak.

But it changes idle significantly when I spray carb cleaner near the bottom of the bowl.
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Okay, maybe I should have called it a vacuum leak.
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What do you think the issue is?
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Either way, I bought two rebuild kits. I can check all the hoses, connections, and seals while I have it apart .

 

[Berdink]

I meant to say a vacuum leak.

 

[saltchuckmatt]

What are you idling at in your driveway rpm wise?

Throat of the carb is grabbing some of your carb cleaner...even if the bowl had a seal problem it would just leak.

1100 out of the water

Post compression numbers.

Idles probably to low.

 

[Berdink]

Last time I ran it in a 55 gallon drum cut in half filled well above where the lower unit meets the midsection - probably around 6 inches above the cavitation/ventilation plate.
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I need to get a tach.
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Cold Compression is around 120psi.
120, 119, 121, and 126 PSI

 

[saltchuckmatt]

Last time I ran it in a 55 gallon drum cut in half filled well above where the lower unit meets the midsection - probably around 6 inches above the cavitation/ventilation plate.
.
I need to get a tach.
.
Cold Compression is around 120psi.
120, 119, 121, and 126 PSI

You can do it by ear....should be high in the barrel and quite a bit less in the lake. As long as it's not slamming into gear when shifting.

 

[Berdink]

I'm going clean the carbs, inspect all hose connections, and check everything over.
It's probably time anyway.