Possibly ran without oil. What to check?

SouthSeaPirate

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Some of you already know that I just picked up a new to me pontoon with a 99 Johnson 50.
Took it for a short test the day I bought it. Probably 10 minutes and idled fine.
Today and yesterday I fired it up and it wouldn't stay running unless I had the lever pulled up. Sounded like it was just too low RPM. Also seemed like it was throttling up and down. Had it running probably no more than five minutes total with longest run at one time being 2 minutes.
Mind you the day before I cleaned up the fuel lines and tonight noticed a kink in the line coming in to the fuel pump.
Didn't have a chance to fix it tonight but I thought about it more and more. And started thinking about how little it smoked, or rather lack of. Then it occurred to me that the fuel I saw yesterday was too clear. Went and poured some in a glass and saw only very light blue.
I'm assuming it is straight fuel.
Now, all that said, where do I start? Throw correct mixture and sent it? Comp check? Scrap it?
 

RBoyd1971

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If you use Startron fuel stabilizer or even some others, the fuel can look more normal color or even orangish looking. It kills the die in the oil. Your gas may have oil just the dye has been affected by the fuel treatment if you are using any.
 

iggyw1

Ensign
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Oct 24, 2011
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As for knowing if there is oil in the gas or not, you can pour some gas thru a paper coffe filter and see if it stained with oil or not when the gas drains thru it and it is empty.
 

racerone

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Is the VRO in service ?----Tested ?----Did seller say you had to mix gas and oil at 50:1 ratio ?------Model # of this motor ?
 

poconojoe

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As suggested, some of the new oils are not really that colorful.
I was filling my leaf blower and the fuel also looked too clear, but I knew it was a mixture.

It doesn't sound like it seized, so mix up some new fuel/oil, just to play it safe and try it out.
 

SouthSeaPirate

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Sorry for the late reply everyone. I couldnt get to it again till today.
Looked closely again at the fuel today and seem there had to be some oil in it. There was a small bit of purplish tinge. Looked at the oil that came with all the other junk and saw it was indeed purple. From here I still swapped out the fuel for known good.

Comp was checked warm at 103 and 95.

There is no VRO.

Still wouldnt idle without lever up. Would rev easy if manually opening the throttle.

Decided to spray some carb cleaner in the carbs. Just a little bit to let soak for a few. Doubt it would do anything but figured wth, why not. When I did this I observed something strange, at least strange to me. When spraying in the top carb the engine would bog. Sprayed in the bottom carb and it revved high. I could replicate this consistently.
 
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racerone

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If the engine bogged with the spray it tells me the top carburetor is working.-----If the spray in the bottom picks up the speed then the bottom carburetor is NOT working.---Should be an easy fix.----What fuel pump is on this motor?----95 PSI is too low in my opinion.
 

SouthSeaPirate

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If the engine bogged with the spray it tells me the top carburetor is working.-----If the spray in the bottom picks up the speed then the bottom carburetor is NOT working.---Should be an easy fix.----What fuel pump is on this motor?----95 PSI is too low in my opinion.

PSI too low. Does that mean the engine is shot?
The pump looks like this one; https://www.startpage.com/av/proxy-image?piurl=https://images-na.ssl-images-amazon.com/images/I/81sn%2BN53BvL._AC_SL1500_.jpg&sp=1623293227T7b9c609b7556749c49b3a7be55a33960c5002064e494f66a283b11b508d27dfc
Bottom carb bowl was def full of fuel. Dont know if that says anything.
 

racerone

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I say the bottom carburetor needs attention.----At 95 PSI on that I would pull the cylinder head to inspect cylinder.-----Head gasket is cheap.
 

SouthSeaPirate

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Update: So I pulled the carbs and they were VERY dirty. Used a bread tie wire for the very small passages, brass wire brush for scrubbing, and a whole lot of carb cleaner. Gaskets looked good, jets clear, pretty spotless.

Still would only stay running with throttle lever up. Strangely it would delay revving up to higher RPM, but would get there. When manually operating the throttle on the carbs and it would respond instantly. Ran great honestly.

Note that the bottom carb will bog when I spray cleaner now. Still not as instant as the top cyl.
Did comp check again and I got 95 and 93 on a HF brand tester. I hear they are not as good.
 

lprizman

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I would've mixed new fuel and ran it....first
Best of luck with your surgery....at least you'll learn alot..... always new gaskets
 

racerone

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There is a little item screwed into the carburetor bowls.-----High speed jet.-----( called orifice plug on the parts manual ) that item must be clean.-----Did you have it out for cleaning ?----It is way inside behind the drain plug.
 

SouthSeaPirate

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I would've mixed new fuel and ran it....first
Best of luck with your surgery....at least you'll learn alot..... always new gaskets

I did run it with new gas
When you say surgery, are you implying it is major work ahead?
I don't want to invest money into a dead engine.
 
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SouthSeaPirate

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There is a little item screwed into the carburetor bowls.-----High speed jet.-----( called orifice plug on the parts manual ) that item must be clean.-----Did you have it out for cleaning ?----It is way inside behind the drain plug.

I couldnt get the jets out. Def was going to break if I tried any harder. I sprayed it and looked clean. Checked with lights in multiple directions. Could see through no problem.
 

SouthSeaPirate

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Update: So I went and rented a compression tester from AutoZone. Way different results, however, I had both the carbs off. So not entirely consistent test. I would have tested with the carbs installed, but I took them off again earlier to inspect and clean again... then it started pouring. Tho I did test with the HF brand and I couldn't even get 30 psi.
Results with OEM is 139 and 141.
 

SouthSeaPirate

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How do you guys feel about the new numbers?
I feel like too good to be true.
Should I rent yet another tester?

Ill test again when I get home tonight.
Ill also order the carb rebuild kits.
 
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