Servicing Carb - Vacuum Line Mixup - - The home of the Kawasaki EX500 / Ninja 500R
  • 1 Post By RickmanCR750
  • 2 Post By ducatiman
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post #1 of 7 (permalink) Old 4-16-2019, 4:36 PM Thread Starter
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Unhappy Servicing Carb - Vacuum Line Mixup

Hey forum,

So I'm far from being mechanically-inclined, as you'll soon find out from my current failure.

I was attempting to seafoam my carbs to see if they'd shape up after an extended period of being stored without proper stabilization. I pulled the fuel tank and drained the bowls. The intent was to put seafoam directly into the carb through the fuel line and let it sit for a couple of days to do its thing. My mistake came in the form of putting the seafoam into the vacuum line instead of the main line.

Is there any major issues with having done this? The intent was obviously to drain the seafoam from the bowls, hook the gas tank back up, and refill the carbs with fuel and just fire it up. I'm guessing I need to get the seafoam out of wherever it went by putting it in the vacuum line?

Any tips are appreciated.

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post #2 of 7 (permalink) Old 4-16-2019, 5:03 PM
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I think the vacuum is generated by the air rushing through the carb body or main opening, so you may have just dumped it in and it slowly dripped in to the cylinder. It should not cause any serious damage but you are still going to need to pul them and clean them the right way. Or send them to our resedent pro.

1993 Teal/White EX500 6K First Street Bike
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post #3 of 7 (permalink) Old 4-16-2019, 5:11 PM Thread Starter
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I got a pretty good amount of seafoam into... wherever it went... through the vacuum line. Probably 3/4 of a bottle. I put the rest of the bottle into the main line until it wouldn't take anymore, and opening the bowl drains shows that there is some in there.

I guess my question is if I can just drain the bowls now, hook up the gas tank, and fire it right up? I already tried that and didn't get anywhere (won't really turn over even), which made me think that the seafoam had gotten somewhere I couldn't drain off, keeping the fuel from getting to the spark plugs.

PS - The bike ran before I did this, just had to keep the choke all the way open and any throttle would kill it.
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post #4 of 7 (permalink) Old 4-16-2019, 5:34 PM
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If the engine won't turn over it sounds like you have piston lock from the Sea Foam going into the cylinders. On the compression stroke the liquid won't compress and locks the piston. I would pull the spark plugs and then when you turn over the engine the liquid will blow out the spark plug holes. You should also clean the spark plugs before putting them back in. You could also wait for the Sea Foam to leak passed the rings, hard to say how long that will take. You might also want to drain the oil because that is where the Sea Foam is going or not depending on how much got by. When the bike does start its going to smoke for a bit until the Seam Foam is burned out.
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post #5 of 7 (permalink) Old 4-16-2019, 5:42 PM Thread Starter
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Thanks Rickman. That's great info. Much appreciated.
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post #6 of 7 (permalink) Old 4-17-2019, 3:40 PM
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a little late now, but the carb vac line is obviously ported inboard of the throttle plates, directly into the constant "suck mode" when the bike is cranking or running. Whatever amount of liquid was introduced via the vac line was sucked straight into the chambers, as @RickmanCR750 correctly posted.

When cranking to expel, spark plugs removed....use care and safety goggles....whatever remains in the chambers is gonna vigorously shoot straight up outta there! Dangerous to you and bodywork, etc. Loosely draping old towels over the spark plug areas a good idea, while you turn away from the mayhem.
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post #7 of 7 (permalink) Old 4-18-2019, 12:40 PM
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Yeah, 3/4 of a can is surly in the engine, I have an engine in my basement that has a bent crank do to a hydrolock so def dont go cranking on the starter. Remove the plugs as mentioned and de-flood the engine before going any further.

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