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vacuum cap missing?

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Old Oct 15, 2013 | 07:33 PM
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Default vacuum cap missing?

Bike has suddenly been missing/skipping at light throttle. I noticed a vacuum nipple exposed under the gas tank basically on top of throttle body. I plugged it and bike idles well. Too late for a test ride.

I'm assuming it should be capped.. Right?
 
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Old Oct 15, 2013 | 07:37 PM
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There was just a thread on this a couple days ago. Yes, cap it and your ECM will need time to relearn. Try searching for it or looking through the first couple pages I this forum.
 
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Old Oct 15, 2013 | 07:40 PM
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Originally Posted by Rustrtal
There was just a thread on this a couple days ago. Yes, cap it and your ECM will need time to relearn. Try searching for it or looking through the first couple pages I this forum.
Thanks. I do recall a similar thread but my search came up with a bunch of threads that were not pertinent.
 
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Old Oct 15, 2013 | 07:42 PM
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I seen a thread on this before I left Afghanistan, a fellow rider could not for the life of him figure out why his bike would not run right, he was talking to an old rider one day, the guy said " did you check the vaccum cap on top of your intake?" Sure enough that was the problem...
 
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Old Oct 15, 2013 | 07:45 PM
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Just found the thread from a few days ago. Exact same vacuum nipple. Maybe I found my problem as well..
 
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Old Oct 15, 2013 | 08:18 PM
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If your bike ever backfires through the intake it will/can blow this cap off. It is a tight fit, so I doubt they are just falling off. I have suspected some getting pulled off as prank. It happens more than you may think.
 
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Old Oct 16, 2013 | 06:54 PM
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Update: put vacuum cap back on. Loaded back my FM base map for my tw555s. Bike ran great today. Drove to work. Home for lunch. Back to work. Fine. Came home tonight and back to missing. Skipping. Bad raw gas smell at idle and when I shut it off. Perplexed. Any ideas? 2012 rkc. Did cams two weeks ago and bike ran great until yesterday.
 

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Old Oct 16, 2013 | 08:14 PM
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Nuttin?
 
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Old Oct 16, 2013 | 08:38 PM
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Not sure if this will fix it, but here is the map we are running on 2012 Limited with the same setup as you have TW555, V&H power duals, 4 in Jack pot, SEAC, and power vision. The idle when you put cams in due to low vacuum/ reversion will idle at 50% load to 100% load which is much different than stock which idles at 20 to 30. Try it you don't have anything to lose. It will definitely improve the performance. The timing is the main difference. If it idles rich with this one something else is wrong. Let me know how it works.
Make sure you always delete the learned values when you install a new map or changed map when it asks.
 
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Old Oct 16, 2013 | 08:58 PM
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Originally Posted by ke5rbd
Not sure if this will fix it, but here is the map we are running on 2012 Limited with the same setup as you have TW555, V&H power duals, 4 in Jack pot, SEAC, and power vision. The idle when you put cams in due to low vacuum/ reversion will idle at 50% load to 100% load which is much different than stock which idles at 20 to 30. Try it you don't have anything to lose. It will definitely improve the performance. The timing is the main difference. If it idles rich with this one something else is wrong. Let me know how it works.
Make sure you always delete the learned values when you install a new map or changed map when it asks.
Thanks. Got nothing to lose at this point as you said.
 
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