Gas coming out of vacuum port - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 7 (permalink) Old 04-29-2009, 02:52 AM Thread Starter
 
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Gas coming out of vacuum port

Was checking different things that could be wrong (see Pulls hard butt farts at 40) without getting into the ignition stuff. you know, check out the easy cheap type fixes first. I capped the right (rear) carb vacuum port, removing the emission control line. And boy she ran pretty good the 1/2 mile to the expressway all the way to the exit about 8 miles. No missing like I was complaining about in the other post. But in regular street traffic was farting badly and wouldn't idle at all. Pulled off and changed back to the original config. with no change. Got her home and this morning figured I'd check to see if the hose or plug was leaking. Pulled it off the carb and gas comes out of the vacuum port. A lot of gas. Carbs were just rebuilt with new float needles last month. Anyway I pulled the rear plug and they were wet. Drained the oil, don't know if it's contaminated leaking down the cylinder all night. But before I fill her up again I need to figure out why I would have gas there at the vacuum tube. Any thoughts? Thanx 4 reading.
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post #2 of 7 (permalink) Old 04-29-2009, 04:28 AM
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Quote:
Originally Posted by Rexweldster View Post
Was checking different things that could be wrong (see Pulls hard butt farts at 40) without getting into the ignition stuff. you know, check out the easy cheap type fixes first. I capped the right (rear) carb vacuum port, removing the emission control line. And boy she ran pretty good the 1/2 mile to the expressway all the way to the exit about 8 miles. No missing like I was complaining about in the other post. But in regular street traffic was farting badly and wouldn't idle at all. Pulled off and changed back to the original config. with no change. Got her home and this morning figured I'd check to see if the hose or plug was leaking. Pulled it off the carb and gas comes out of the vacuum port. A lot of gas. Carbs were just rebuilt with new float needles last month. Anyway I pulled the rear plug and they were wet. Drained the oil, don't know if it's contaminated leaking down the cylinder all night. But before I fill her up again I need to figure out why I would have gas there at the vacuum tube. Any thoughts? Thanx 4 reading.
Stuck float valve or debris in float valve.


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post #3 of 7 (permalink) Old 04-29-2009, 09:20 AM
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Is that vacuum line the one that goes to the petcock? It could be a bad diaphram in the petcock letting gas straight in through the vacuum line. We've seen that before.

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post #4 of 7 (permalink) Old 04-29-2009, 09:56 AM Thread Starter
 
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The petcock was just rebuilt with a new diapragm. Carbs just rebuilt with new float needles. Tank was just derusted and POR15 coated so some chunk might have broken loose. I'm going to apply vacuum to the petcock to see if I can reproduce the flooding while it's sitting dead in my garage. I wanted to put filters in the lines but my patience was too thin and my fingers too fat.
George
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post #5 of 7 (permalink) Old 04-29-2009, 09:58 AM
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Quote:
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Is that vacuum line the one that goes to the petcock? It could be a bad diaphram in the petcock letting gas straight in through the vacuum line. We've seen that before.
Nyet; he said right (rear), so it's the one going to the air switch. I'd guess lance328 prolly hit the nail on the head...

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post #6 of 7 (permalink) Old 08-12-2015, 02:50 PM
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I am having the same issue, took it to a Mechanic and he says That The Floats were not dark and there was no debris either. So what could be the cause in my case?
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post #7 of 7 (permalink) Old 08-12-2015, 06:25 PM
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I am having the same issue, took it to a Mechanic and he says That The Floats were not dark and there was no debris either. So what could be the cause in my case?
You replied to a post from 2009. It also has the solution.

Quote:
Is that vacuum line the one that goes to the petcock? It could be a bad diaphram in the petcock letting gas straight in through the vacuum line. We've seen that before.

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