How to Clean Carburetor in Place in an Outboard That Cannot Start - Follow up

[jaykchan]

I posted a message two to three days ago about my outboard (T8) that I could not start. Because I cannot find a way to remove the carburetor from the outboard, I have to clean the carburetor in place. The complication is that the instructoin of SeaFoam (that I plan to use) only describes the way to use it with the engine still can run. Mine could not start. I tried to find out the way to flush the carburetor in that situation. The message was still in this forum in this morning. But by this evening, the message has disappeared.

I am posting this again because I have found the exact steps to flush the carburetor in my outboard (T8) that could not be started in the normal way:

1. I got a can of starting-fluid and a can of SeaFoam Spray.

2. I removed the air intake duct. I found that I couldn't use SeaFoam properly with the air duct in place. It has to be removed.

3. I opened the air intake valve (using the choke lever) of the carburetor, and sprayed some starting-fluid into the carburetor.

4. I closed the air intake valve (full choke), and started the motor.

5. The motor started with the starting fluid. The motor smoked quite a bit with the starting fluid. But it would soon stop when it burns out the small amount of starting fluid. I opened the air intake valve before it burned out the starting fluid. I sprayed more starting fluid into the carburetor to keep the motor running. And I kept spraying starting fluid whenever the motor showed sign of running out of starting fluid (it made different sound). After a short while, I got used to this cycle.

6. At that point, I introduced SeaFoam. When the outboard started showing sign of burning out of starting fluid, I sprayed SeaForm into the carburetor instead of starting fluid. The SeaFoam acted like the starting fluid to keep the motor running. The SeaFoam smoked quite a bit just like the starting fluid. I kept doing this for a while. In my case, I don't know if this step really helped or not; the reason is that the motor stopped if I stopped spraying SeaFoam. But this step was exactly the step that I took; therefore, I need to mention this.

7. I soaked the carburetor with SeaFoam (I guess this is called "Hot Soak"), and let it sat for 5 minutes or so.

6. I started the motor without the use of any starting fluid. There was plenty of SeaFoam in the carburetor as fuel. In the beginning, the motor smoked quite a bit (as expected). I was expecting the motor to stop at any time. But it didn't stop. It kept going. After a while, the smoke reduced significantly; I believe at this point the carburetor was flushed, and it was getting regular gasoline from fuel line instead of using SeaFoam as fuel. I let it running for another 10 minutes or so just to be in the safe side.

7. At this point, I believe the outboard is ready to use. But I think I will need to run a gallon of gasoline that has been treated with SeaForm into the motor just to be in the safe side, and I need to do this soon. After all, my mechanic had flushed the outboard before, and the problem came back after the motor sat for one month. Therefore, flushing it once doesn't seem to be enough. I believe I definitely need to run a gallon of treated SeaForm through the outboard.

Please note that the steps above were exactly what I did. Some steps might not be necessary. But I have no idea which steps are needed and which steps are not.

Hope this helps someone anyway.

If there are other alternatives to SeaFoam, please let me know.

Jay

[jaykchan]

I forgot to mention that the reason why the outboard didn't start had to do with the fact that gasoline was left in the outboard during the winter. Despite the fact that the gasoline had been treated, it still went bad and probably had blocked the fuel intake jet inside the carburetor, and prevented the motor to get any fuel through the carburetor.

My mechanic had flushed the carburetor once one month ago. But I didn't use the outboard one month later. Seem like the treated gasoline went bad enough again after sitting in the outboard for one month. That's why the problem came back. Luckily, I figured out how to use SeaFoam to fix the problem. I will make sure I carry with me in the boat the following items: starting fluid spray can, SeaForm Spray can as well as a wrench to remove the air intake duct.

Jay

[BQUICK]

Spraying the air intake of the carbs does nothing to clean them. If you open all the bowl drains and flush Seafoam/fuel mix it will help clean them out internally (use primer bulb with hose stuck in mixture)....if you don't want to take them off.

[rodbolt17]

and if the jets are not clean then it runs lean at or near WOT and you can post about burned/warped valves and detonated pistons.
best method is removal and cleaning.

[Fins]

Do yourself a favor and learn how to remove the carb, and clean properly. Clogged jet, running lean = big problems.
I just had to remove the carb on my 25 Yamaha, because the needle valve was stuck closed, and no fuel could get into the carb.

Being as I don't want to buy alcohol free gas all the time, I took a gas tank from a old lawnmower, and attached a hose with a fuel fitting.
Now when I'm flushing the motor after use (sale water) I run it on alcohol free fuel from the small tank, so I don't have alcohol fuel sitting in the lines, pump and carb.

[rodbolt17]

yep.
lean is bad.
difference between heating/welding and cutting is LEAN.

[jaykchan]

Thanks for Useful Advices

Thanks for many helpful replies. Sorry I have been busy with the boat and didn't post back until today.

To: BQUICK
Thanks for the tip to properly flush the carburetor with the carburetor in place. I will try that tip next time when I have a minor carburetor problem.

To: rodbolt17
Thanks for the warning about the motor will run lean if the carburetor is not fully cleaned. I took your advice and checked the spark plugs. Surely enough, the spark plugs were silver/white color and very dry. Seem like the motor was running lean even at idle/slow speed. I have asked a different marine mechanic to look into this problem. And he said he likely needs to disassemble the carburetor and clean it thoroughly. I will see how this goes. This marine mechanic seems to be MUCH more experience than the last one. I have confidence that he will be able to fix this.

To: Fins
Yes, I would much rather be able to disassemble the carburetor and clean it than just flushing it. But I cannot figure out how to disconnect the link to the remote choke. I have checked the service manual, and it doesn't say another about the remote choke. Seem like the service manual doesn't cover optional feature of the motor. Oh well... Actually I have a message thread asking about this in this forum. So far I have no luck in finding out how to disconnect the link to the remote choke. I am hoping that someone who has installed the remote choke before will be able to tell me how to disconnect it.

[rodbolt17]

best I recall you pull the carb and choke solinoid assy then remove the oring holding the link rod to the carb.
not hard typically takes me about 1.5 hours to do the T 8.

[jaykchan]

Will Try Your Tip to Disconnect Remote Choke

You are the second person suggesting to remove the O-ring in order to disconnect the remote choke from the carburetor. I have another message thread about this issue ("How to Remove a Carburetor from a T8?"). If two persons suggesting the same advice, I think this must be the right way. I will try this when I get back my boat.

Jay Chan