stall under hard braking

[psycoreefer]

Hey guys, I've got a strange symptom, my bike runs good, starts easy, easily pulls past red line. I've been doing some more aggressive riding and I've noticed that about 1 in 5 times if I brake hard from 50+ to a complete stop the bike will stall. Seems to do it more often after maintaining a steady speed for a little bit before but could be my imagination. I did try bumping my idle speed up a little bit because I had it set on the low side, about 900, raised it to around 1300 and it still happens.

Any ideas? Things to check?

[Ken Talbot]

Are you perhaps locking up the rear wheel? Lock that up, and the engine has no choice but to stop.

[petejw]

it could be either a little rich or lean,
you could try turning the mixture screws
a little 1 way and take it for a hard ride
and compare then the other way, and see if that helps.

have you got your float heights set at the stock settings?

[psycoreefer]

Ken, nope not locking up the rear, happens even with the clutch pulled.

Pete, I do have my floats at stock height, I had them set "rich" and recently adjusted them back to stock. I moved from SL to 5000ft. I'll try tweaking the idle screws.

Keep the ideas coming.

[XS1100 Newbie]

It sounds to me like when you are running hard, the float bowls may be running low, and when you brake hard, it is throwing the fuel forward. That would cause a loss of fuel. Maybe have to set that float level a little higher if you are going to run that had, or quit braking so hard.

[petejw]

at 5000 feet you might be running on the rich side,
try leaning out the mixture screws a quarter- half a turn,
also check out the colour of your plugs to give you an idea.

[jmelin]

I go with the floats to low.

[draketrumpet]

this happened to me last night. I was sure the light would change before I got there, there were no other cars at the intersection, but it didn't change and had to break hard to not run it. I was coming down from about 50 or so.

Haven't looked at the carbs yet, waiting to get my kits back as I left them at MoM.

[cywelchjr]

I think he just needs to remember to pull in the clutch when stopping quickly.

I've seen the bike, sounds and looks pretty good, with the exception of the GPS strapped on in place of the speedo.

[greengoon3]

I'm thinking float level also. Could be too high and sloshs when he stops?

[Ivan]

On a full on panic type stop, which I do practice often to get the feel for when the time really does come, the engine dies almost every time. I don't know why, but when my eyeballs are being sucked out of my head from the intertia, I figure the engine is probably having the same problem. The pistons are all smooshed up against the fronts of the cylinders and the cam chain is doing its best to unseat the tensioner. The front tire is nearly breaking loose from the bead in the front part of the wheel and then enduring several times it normal load during hard braking. One time I think I actually had a contact lens fly off and get stuck to my helmet visor. The state sent me a letter saying they are tired of me plowing troughs in the pavement, and to do that in Oklahoma where they have a astronomical highway budget.

Really though, when you get used to it, you can just pop the clutch and let off the rear brake at about 10 mph and it will restart, and you can look at the guy next to you and say "I meant to do that."

[psycoreefer]

popping the clutch is what I've been doing when it happens, thats how I know I'm pulling the clutch in. I'm not panic stopping but I'd say that I'm about 95% of a panic stop when it does happen. Thing that gets me is it doesn't happen every time, and I'm sure that they didn't do it from the factory. I haven't had time but I'm going to play with the mixture and float settings and I'll report if I find a cure.

[Ivan]

Best I can tell is the fuel sloshes forward and makes the idle circuit overly rich. On the older carbs with the caps over the idle jets, that should be minimized, but it still happens on my 79. Since its the same on either bike, I just assumed it was part of the character of the XS11.

[draketrumpet]

my nose supports the overly rich assessment. Today I hard braked at 25 and while it didn't die, it tried to, and I got a nice whiff of gasoline.

[yamtom]

same thing

Hi,

I am having the similar thing, only mine only sounds like its gonna stall, never actually goes below about five hundred on the tach. Its in the last twenty feet or so in coming to a stop, the rpm just drops,, then about the time that the fuel should be sloshing back, it recovers to a thou on the tach. My floats are dead nutz on at 23 mm,, and the screws are set at one and a quarter, exactly where yammi wants em....No real problem for me, but lets hear what curez yourz, maybe I will try that too,, psyR.