LF, you have spewed that wrong info before, and I baited you to posting it here. Time for you to check yo self foo!
LOL. Honestly, Cliff Claven-Fringe could be right, but trying waaaay too hard:sleeping:
OP:
I wrote a concise answer that applies to you. Don't worry about him adding confusion here, LF is over-achieving for my sake, not yours. I'm his catnip
You can put a plug on there if it makes you feel better, it won't hurt anything. Neither will leaving it alone. So, if anyone still cares...
Blah, blah. I am posting
concise information that
applies to the question. You are posting mis-information that
does not apply to the question asked. OH, and is wrong.
It is the port for that, but it is
not open to vacuum.
Absolutely false. It is not missing a plug, you would know right away for the reasons listed below. The factory never installed one there, because it is
not open to vacuum on your bike Dan.
NO.
Even if it was a California bike... with a missing canister... and missing plug... It is still PORT vacuum and insignificantly exposed to vacuum when at idle.
That is the purpose of a "port vacuum" signal. The port would only be open off-idle.
Still NO. Once again, even if port vacuum is left open, when you close the throttle, that "ported vacuum", is effectively
closed to vacuum and therefore unable to affect idle.
That is a picture of a factory stock TB, without any plug on that nipple. Thank you for proving my point in your own post
All Buell XB throttle bodies do have that nipple. BUT, it is
wrong to assume (and post as 'fact') that it is open to vacuum. Only the XB's destined for California and some off-shore, had the port machined through into the throttle body, and the appropriate compliant Evap emissions system installed.
Thats why theres no plug on yours now. Because the factory did not put one on it.
People commonly (but wrongly) think that is a port vacuum leak because, they assume
incorrectly that any open fitting, is open to the throttle body.
Yours is not Dan,
because ALL of the conditions below would have to be met, and you
still would have BIG clues I would have addressed in my original, and concise post to you.
IF your bike was originally a California (or some off-shore) bike (it isn't) and,
IF someone removed that canister, and
IF they removed the port vacuum line at the TB, and
IF that person didn't plug that port when they took the line off,
Then you'd have a leak. Duh. And it would not be a "minor" leak. An open 5/16" hole is a TON of airflow. So,
your bike would stutter off idle, run massively lean, run hot, and you'd have a big CEL in your face. Since you didn't mention
any of those issues in your original post, your bike has a extremely high probability of not having the hole behind that nipple in the TB machined open and therefor NO leak there at any throttle opening.
Just like the VAST majority of Buells.
Thats why I didn't confuse the question, explaining that uber-rare circumstance,
thats why the factory doesn't put a failure prone plug on that nipple,
and that's why you didn't mention any running issue,
and thats why you don't need a plug on yours.
Wanna be 100% sure? Start it, crack the throttle, and put your finger over it. I'd put 1000 crispy internet points that it does not pull vacuum. If I'm wrong? Well hey, put a plug on it and I'll take my lashings.
To outtheres point: Yes. Be very sure the bottom of the TB airhorn gasket sandwiches the lower airbox plate. XB's are
very sensitive to any intake leaks. Further proving my point.
TL;DR Sorry everyone, for the wall o' text. I wouldn't normally GAS but that guys gone all cray-cray over me. I can hear Cliff Claven-Fringe slamming keys frantically researching other off-topic exceptions, hovering over the 'ALL CAPS' button. This is fun!