Strange sporadic idle sucking sound w/ stall?
 

Hi! Maybe someone here has insight into my superwhale issue?

The bike - 2005 California VTR, 20,000 miles, PAIR valve disabled, some holes drilled into the back of the exhausts (previous owner). I've owned it for maybe 600 miles.

After 30 minutes or so of normal use, the bike occasionally has a low, wimpy idle at stoplights. Temperature will be around 209, bike idle will lag around 1000-900 and possibly stall, even if I crank the idle stop up to 1800 rpm while it's healthy. Then, sometimes when it's idling at normal 11-1400 speed, it will hiccup every 3-5 minutes, possibly stalling it again.

Any ideas, any more clues I can provide? I had the carbs apart and cleaned up 250 miles ago. Could some crap have found it's way into the idle circuit? When I put the bike back together, I accidentally routed the vacuum line to the fuel overflow and not the back of the petcock, but that's fixed now. Thanks for responses-

-Ian

Did you sync the carbs after re-assembly? If not go do that ASAP...

I have an 05 Cali model as well. Is your EVAP canister removed? Easy to tell if it has been, since it resides just above the left side of the chin fairing, about the size of a coffee can. Greg Nemish's web site has directions for removal at superhawk996.net. Just ignore the tip about leaving the 2 small vacuum hoses open with a filter on them, plug them instead.

Also a needle shim on the carbs would help, if it hasn't been done. You can do a search, usually .020" to .040" using #4 brass washers works. And check pilot screw adjustment.

But a big bore twin with 48 mm carbs will have the occasional carb fart.

Thanks for the replies. I have not sync'd the carbs yet, (it was on my to-do list) and I did not plug the two vacuum lines leading to the st. bernard evap jug when I tossed it. I'll plug those lines and sync the carbs.

*UPDATE*

I was riding on the freeway in Los Angeles this evening, having plugged the vacuum lines as stated above. Suddenly I lost power, and had to shift down to fourth to keep it chugging at 40. I maneuvered over to a construction lane on the shoulder, amidst speeding cars and what have you, and when I shifted down to neutral (with nothing to keep the RPM above 3) it died.

I wasn't sure what to do, only that I needed to get off the shoulder as fast as I could. I ripped out the new vacuum plugs. Wouldn't start. Then for no logical reason (instinct?) I worked the choke plumber in and out a few times. It felt harder and easier on different pulls. The bike had also smelled sorta rich when I had started it at the gas station. It fired up well enough, and I rode home.

A few minutes ago I looked into the under-airbox area with a flashlight, and the choke cable leading to the rear carb looks looped around in an odd way. No kinks, but doesn't look quite right. Tomorrow I'm going to pull everything apart and inspect it. While I'm down there I intend to do a sync, shim, pilot adjust, and anything else that comes up. Thanks again for the ideas.

In regards to the stalling on freeway. I do find sometime I fill the tank up to neck and quickly ride off, the pressure inside the tank create vacuum to prevent fuel flow and cause the stall.

I usually just pull over and open the fuel cap and close it. This seem to be a quick fix.

What is actually happening in that case is that fuel is getting in the vent line and creating a loop seal, such that air can't get to the tank. The tank pulls a slight vacuum and subsequently won't gravity feed the carbs. Quick fix: Don't fill the tank as much or, if you do, take it easy for the first few miles (no wheelies or stoppies). Long term fix: Reroute the tank vent line such that there is a straight path from tank to ground, with no place for fuel to sit.

I had just filled up before heading out, and I topped it up pretty high. Hmm...

Are you talking about the #5 hose, the one with the T?
Also, with the one vacuum nipple on the carb itself, the one that connected to the PCV, do I block that one as well?

*Update*

Took off all the emissions stuff, plugged the appropriate holes, tee'd into vacuum lines on both carbs for the purpose of sync'ing them.

Now, one of the vacuum lines goes into the back of the petcock (the angled spigot). I tee'd into that line to get vacuum for the rear carb: but when I run it for a few minutes and turn it off, take the rubber cap off the T nipple, fuel comes out. That can't be right?

I'm going to tear apart the petcock and inspect the diaphragm

half inch tear in the vacuum diaphragm! little f**xer

just got my diaphragm repair kit from carbkitcapitol.com... goldwing aspencade 1991-1995 version. Took over a week to get here, but only cost 20-something after shipping.

So far, after warm up and riding around the neighborhood, there's no sign of the original problem. There is a hesitation/stutter early in the throttle, but I'll see what happens to that after doing the carb sync.

Synced the carbs, got rid of the stutter, but a little gas still comes out when I pull the rear carb - tank vacuum line (it's in the right spot). Also, it just feels like it doesn't have the juice. Before I cleaned the carbs, I could power wheelie in second with a modest throttle rip and sitting back in the seat a little, now it's just not there. argh