[hunz]

Hello all - no pun intended with the title

Anyway - had the carbs out tonight in order to rejet for my new baffles (more substantial than the lollipop baffle).

Anyway, with the normal amount of pain and suffering, I got everything back together. Decided to start it up to make sure I didn't royally screw it up and noticed a hissing noise when the choke is applied with the engine running.

As far as I can tell it goes away or is just less noticeable when the choke is closed (off). By opening and closing the choke I was able to trace it to somewhere above the front cylinder, up by the steering head.

As far as the noise itself, it's not a high pitched hiss, but more of a sound of air being sucked through an orifice (similar to the sound of blowing out of a straw). As far as I can tell, everything is connected...

Anyway, just curious if anyone knows if this is normal? It may be, and I just never noticed it before, but I figured I'd probe the knowledgeable minds on here.

I may try to check for any leaks in that area if I find some matches...

One other thing, does anyone have any tips for those dang choke plungers? Mine have a rubber "boot"/"sheath" around the cable and that nut/threaded portion that fights every turn of the nut as it is "gripping" the nut and trying to twist around the cable.

 

[swifty2014]

If you want to locate sounds you can get a piece of hose like a 5/8 inch heater hose and hold it up to your ear and move it around the suspect area. It can help amplify the hissing.
On the choke nuts, WD-40 or soapy water would help them spin better and dry up later.

 

[hunz]

swifty - thanks for the tips. I'll see if I can pinpoint the noise location tonight and go from there. Part of my thought process was that perhaps I only noticed it since the tank was off the bike.

 

[5l1mm]

if this 1100 is anything like my 86 1100 then the choke is cable driven and pushes/pulls needles that allow fuel to bypass the jets and richen up the mix. not a whole lot to do with air moving or hissing
my guess is the choke is coincidental, and the noise might be an airbox plumbing issue.

 

[ttexastim]

Quick way to see if you've got air sucking somewhere it shouldn't be is to fire it and spray starter fluid around the area. If no leaks, there will be no change in engine speed. If any of that stuff gets sucked inside, you'll hear it rev up.

 

[jpr1968]

My guess is that there is a leak by the choke(s) at the carbs.

 

[hunz]

Yep - it's a cable driven choke... that's part of what puzzled me. Didn't make sense to have an air noise when actuating a cable...

I'll stop at the auto store and grab some starter fluid on the way home today and give that a try. Had a reasonable quantity of brews during this activity, quite likely I goofed it up putting it all back together.

 

[5l1mm]

maybe the intake plenum wasnt properly seated to the carbs, and your air filter is dirty?
that would cause leak around the boots that connect the plenum to the carbs

 

[swifty2014]

It could sound different maybe as you pull the chokes because the plenum is leaking a bit and the chokes change the air flow inside the venturi. Maybe ???

It is safer not to drink and ride and/or drink and wrench !!!

 

[hunz]

Turns out i did leave off a hose going to the "secondary airbox". But that wasn't making the noise. Still there. Can't find any leaks anywhere as of now.

Put it all together and rode it around the block. Throttle response is good and it seems to run fine.

Probably nothing severe, but I'll monitor it and continue to check for leaks. Next time, I won't be drinking...as much.
Cheers and thanks all for the input!

 

[duncankane]

any info on this? my vt700 does the same hissing when choked but runs absolutly fine