Finally got the popping stopped! Thanks Murdoc, Mojo, and Bones!!!!!

[Dave Weaver]

I now have a '97 Tourer that runs like a Valk should; no more popping at idle, decel, accel, or any other time. It idles smoothly with no fluctuation and when I crack the throttle in 3rd gear she wants to bring the front end off the ground.  You can check my old posts to see all of the problems I had with bike, and measures I tried to correct problems.  I went to Murdoc's house today to see if he could help me. We synched carbs and looked all over a vac leak we could hear with stethoscope.  We tried several things, but still had a popping we could not get rid of. I was all set to go home when Mojo and Bones pulled in.  Mojo got to listening and looking around and found the leak.  It was coming from a tear in the vacuum line that is on the side of #4 carburetor that attaches to the air cutoff valve.  This is the little hose that is on each carb and attaches from valve on lower side of carb to upper side of carb. I had replaced that line in January along with all the other vac and fuel lines, but must have ripped it sometime.  We replaced the line and immediately the bike was right.  I rode it home 150 miles and am tickled to death.  Thanks again guys and I will let you know when I am ready for the wrench party to try out Mojo's new tire changer.

Dave

[RP#62]

Thanks much for posting what you found. I don't think I've ever seen any previous posts of this line failing. 
-RP

[Murdoc]

That was a real puzzler.  Like I said when we started, look for the simple stuff first!    I'm sure glad the boyz showed up when they did to help figure out where the leak was.  Like RP said, I've never seen one of those little tubes leak before, but from now on I'll make sure to check.  Glad the bike runs right now.   

[Paul Carver]

Dave, I also have that poping sound that I am dealing with. Took it to Niehaus Cycle in Illinois to have them change the vacuum tubes with no positive results. When I talked to the mechanic he told me that he changed 2 lines, one having a big crack in it. In your note, you say there is one on each side of the carburators. For us dumbies, would you please point these out in a schematic so I know for sure what you are talking about?
I now have 107,000 miles on my Interstate and this problem is really the only issue I have right now. I appreciate your help!

[Dave Weaver]

Paul,
  There is just one on each carb. It is located where it is hard to see while on the bike.  I don't have a good picture, but will take one later today. It is in the shop manual on page 5-10 under air cutoff valve.  It is item #28 on this fiche.
http://www.hdlparts.com/fiche_image_popup.asp?fveh=3476&section=148732&year=1997&make=HONDA&category=MOTORCYCLES&dc=2291&name=CARBURETOR+COMPONENTS

[Ricky-D]

Yep, it's right there.

If you look at the rear side of the carburetor on number five cylinder the tube is plainly evident and easy to see.

What a great find Dave. 

You have most likely solved the problem that is most reported here on the forum - namely POPPING

Cudo's. Ricky-D

[Patrick]

There was some mention of this problem years ago.. If I remember correctly it was on Glenn's bike or maybe it turned out to be the valve itself that was defective.. Since this particular hose has so few problems we tend to forget about it and all these bikes are now getting old.. Its good you found the problem and brought it to our attention.. I think I'll check my stock of vacuum line and get my hands dirty..

[Paul Carver]

Thanks for your help! Just one more question .... does the tank need to come off to replace this tube?

[Challenger]

Hey Paul! Do I see your I/S in Bradford Il. once in a while? If it's you, I live across the street from Rick.

[FLAVALK]

I recall a member having a problem with one of those hoses many moons ago. It is rather uncommon and I'm glad you found it. Nothing much more annoying than a popping valk!

[Dave Weaver]

You don't need to remove the tank, but you will have to remove the chrome covers that are over the choke slides.  The middle ones will be a bear to get to, but use needle nose pliers or hemostats and you should be able to get to them.  The carbs on the front and rear are easy to reach.

Dave

[art]

I have been having that problem for a year now an have not had any luck .Monday I am going to change those hoses an see if that fixes it .I also have 100000 mi on my valk an I checked those hoses an they are cracked.We will see what happens.Art

[Paul Carver]

Challenger, I remember Rick and Marsha saying something about a neighbor that liked to ride motorcycles. Good to hear from you. Tell Rick I said "Hi".

[art]

changer out the hoses today still have the poping .I'll do the exhaust gaskets next.Art