93 Johson 150hp fuel issue

[Robdean]

Back story
So, the boat was winterizes before it was put away and was working. 5 years later after my dad's passing, I have started working on the boat to get it back up and going. I have drained the tanks, change fuel lines, replaced o rings on the fuel rails, changes the choke fuel solenoid since it had a crack. I made sure the Pisons were free and oiled them before manual turning the engine and so much more.

I am running on a small external tank premixed as I test everything out.

Problem
My question is the motor fires right up and sounds great but only runs on the fuel provided by the choke. I can keep it running as long as i keep pushing in the key at a set interval to give it fuel by the coke bypass. It will slowly run out of fuel and quit if I don't. I am looking at the pump as the issue, but I also know it is vacuum operated and am not sure if it could be the vacuum pump. Ideas or suggestions on checking what could be causing the issue? Maybe a float issue also I just don't know?

Road ahead
I am just making sure I can get it running I have a few more things I will replace like the impeller and a full lower end drop and seal replacement.

 

[racerone]

If it runs with key pushed in the fuel pump is working just fine.----If the motor sat for 5 years with mixed fuel in the carburetors , you need to clean the carburetors.-----Do not run the motor without cleaning the carburetors !

 

[flyingscott]

You need to clean and rebuild the carbs. If that is a looper motor make sure you clean the calibration pockets. Also buy a factory manual.

 

[Robdean]

If it runs with key pushed in the fuel pump is working just fine.----If the motor sat for 5 years with mixed fuel in the carburetors , you need to clean the carburetors.-----Do not run the motor without cleaning the carburetors !

Do you have a way you suggest cleaning them? I have 6 of them.

 

[Robdean]

You need to clean and rebuild the carbs. If that is a looper motor make sure you clean the calibration pockets. Also buy a factory manual.

I do have an original manual. I will look at seeing if I can clean them first if not, I may have to rebuild them. I have 6 of them so to rebuild them will be costly but if that's what I ultimately need to do then I will. I just want to make sure what I am putting money into is the issue that's why I am asking. It sounds like I was headed in the wrong direction already thinking fuel pump.

 

[racerone]

Yes I know your motor has 6 carburetors.----Time to dig in and learn this simple work.-----Or dig into your life savings if you decide on getting a shop to do the work !!

 

[Robdean]

Yes I know your motor has 6 carburetors.----Time to dig in and learn this simple work.-----Or dig into your life savings if you decide on getting a shop to do the work !!

I have no issues doing it any good places to get the kits for less than an arm or a leg?

 

[Chris1956]

The kits are avail aftermarket. Likely Sierra and GLM make them. Make sure they cross exactly with the OEMs, by checking several sites. I had trouble with the kits on a similar motor. The spaghetti seals were real close, but not exact.

The main jet is in the carb bowl. The idle jets are in the throttle body. Check the carb bowls for warpage and replace all that are warped. You can clean the idle mixture needle by removing the cover on the throttle body. No need to readjust it.

 

[ct1762@gmail.com]

these carbs are very easy to rebuild, but you do need a torque wrench in in/lbs. plastic and anything over 50 in/lbs or so can be a disaster so go slow when re-installing and make triple sure the o-rings arent rolled. i put a tiny bit of grease on them if they are stubborn but 80% of the time they are fine.

 

[McGR]

One tip... don't buy the cheap kits from Amazon or eBay. Buy either OEM, GLM or Sierra. The cheap China kits use garbage gasket material that will only cause further problems.

 

[ct1762@gmail.com]

One tip... don't buy the cheap kits from Amazon or eBay. Buy either OEM, GLM or Sierra. The cheap China kits use garbage gasket material that will only cause further problems.

yep. those cheap kits are a nightmare. scary how many have been sold.

 

[racerone]

Carburetor bowl screws are around 10 INCH LBS , and that is not very much.

 

[ct1762@gmail.com]

Carburetor bowl screws are around 10 INCH LBS , and that is not very much.

i was referring to the 4 screws to throttle body. i do remember a few manuals saying 25-35 in/lbs for the carb bowl screws, which seemed absurdly high. i just do them "comfortably" snug.

 

[Robdean]

I have an update. I took a carb off and took it apart. It looks good to me. No buildup of any kind nothing stuck or gummy. I can see down the ports and jets. The bowl is not warped at all, and nothing was leaking or seeping. The only thing I noticed was the bowl did not have a ton of fuel in it. What I saw come out looked to me like it did not have a full bowl at all. What should I be looking for next and are we still thinking this is the reason? What pops in your minds that I should check or clarify?

 

[saltchuckmatt]

I have an update. I took a carb off and took it apart. It looks good to me. No buildup of any kind nothing stuck or gummy. I can see down the ports and jets. The bowl is not warped at all, and nothing was leaking or seeping. The only thing I noticed was the bowl did not have a ton of fuel in it. What I saw come out looked to me like it did not have a full bowl at all. What should I be looking for next and are we still thinking this is the reason? What pops in your minds that I should check or clarify?

How does one know what a full bowl looks like? When you remove the bowl everything that's in there is no longer displacing the fuel making it appear low. Put the carb back on without the carb bowl and while pumping the fuel ball see if the float switch is regulating the fuel. (Manually adjust it up and down)

Everything you have said previously points to a fuel related issue so pretty sure no one is going to know where to go next.

 

[Robdean]

How does one know what a full bowl looks like? When you remove the bowl everything that's in there is no longer displacing the fuel making it appear low. Put the carb back on without the carb bowl and while pumping the fuel ball see if the float switch is regulating the fuel. (Manually adjust it up and down)

Everything you have said previously points to a fuel related issue so pretty sure no one is going to know where to go next.

So i took the carb apart on a tray and i placed the gas on the tray in the bowl and it was not even half full. I am not looking for insight into the future just guidance from those who may know or understand this stuff better. I have new information avaliable so i thought i would share.

I also took a pic of the fuel. When we say gummy i dont know your version and the gas is what i think is very oil thick so maybe thats what you mean by gummy. Take a look and let me know.

 

[Robdean]

How does one know what a full bowl looks like? When you remove the bowl everything that's in there is no longer displacing the fuel making it appear low. Put the carb back on without the carb bowl and while pumping the fuel ball see if the float switch is regulating the fuel. (Manually adjust it up and down)

Everything you have said previously points to a fuel related issue so pretty sure no one is going to know where to go next.

Thanks i will try that also it will tell me more about fuel coming in also.

 

[McGR]

I'd recommend finishing what you have started here - clean, rebuild and reinstall the carbs then you can further access the situation. Rebuilding the carbs is pretty much standard procedure for any carbureted outboard that has been sitting around for several years.

 

[Robdean]

I'd recommend finishing what you have started here - clean, rebuild and reinstall the carbs then you can further access the situation. Rebuilding the carbs is pretty much standard procedure for any carbureted outboard that has been sitting around for several years.

I ordered 6 carb kits. I did get them all OEM for 107 shipped. Not from amazon or Ebay. I would add where I got them, but I am not sure I am allowed to am I?

 

[Chris1956]

Remember, the idle jets, needle and passages are in the throttle bodies. They need to be cleaned as well.