Engine Died During Practice Emergency Stop

[cowboyup3371]

On my way into work this morning, the road I was on was empty enough that I decided to practice an emergency stop from 40mph. I didn't measure how far I traveled but it worked out fairly well I thought except for one issue - the engine died on me. Later in the afternoon, I had gone to get some gas and ice cream (ITS HOT TODAY) and did another practice emergency stop on the way back into the office. Again, from 40mph the engine died. Both times the clutch was pulled in all the way and I was in 4th gear for the entire stop. The engine started right up without a problem once I noticed it.

Now, I can stop with the clutch pulled in all the way, in first gear, and coasting down to the stop without the engine dying. So I am not positive my clutch is the reason although I know a mal-adjusted clutch is one reason for that.

So my question, is there a problem or is this normal? What should I look at if there is a problem?

Thanks

[tatu]

No, I don't think its a problem, mine does it too and I had thought it might be fuel slopping in the carb raising the fuel mix ratio long enough to cause a stall.
If I keep the revs up it doesn't stall.

[Dogma]

Not sure why it's stalling, but you should work downshifting into your emergency stop practice. You may find you need power to escape from wherever you made the unplanned stop. Or, you may need to switch from stopping to evading whatever the threat may be.

I don't think fuel sloshing in the carbs should be an issue if the fuel level in the bowls is anywhere near correct.

Does it die when you get stopped, or shortly after you get on the brakes?

[cowboyup3371]

It died well after I had gotten on the brakes and almost stopped - probably at the point of actually stopping.

I'll work on getting down in gear as I'm coming down. I can do it at a slower speed but I wasn't thinking about that today.

Like I said, it won't stall during any other braking event so maybe I'm doing something wrong; although I do know the clutch is pulled completely in during the entire time.

[pete]

Hmmmm I'd suspect float level too actually... thinking about it, the G forces of the hard braking will cause all the fuel forwards in the float bowls, and it the float height is a little low, that could mean there's not quite enough fuel in there to counter the G force.

I'm probably wrong of course, but that's just what comes to mind...

[cowboyup3371]

Pete, I could see how that is possible. I can tell you that all float settings are currently set at 22.4 +/- 0.3mm

[1_v8_merc]

I have the same problem on occassion as well.

But I recently had one hell of an emergency stop, and no stall!
(Im talking Heavy G forces....I almost flew over the bars)

I was pleasantly surprised, because I already had my finger on the Start Button, then I listened closely and she was still running!

[GSexpress]

It is the carbs and it is normal. The pilot jet can be uncovered and suck air. It is one reason why Suzuki plugged the pilot inlet and feeds the pilot circuit from the main jet as it is lowwer in the float bowl and down in its own well. Raising the float level to the max hight will help but it can still happen. It can also happen from too much fuel if the fuel gets up on top of the floats and lets in too much fuel and forces some up the pipe of the main circuit. When this happens the bike ususally sputters and dies just after the stop. This is why later carbs on GSX'x have smaller odd shapped float bowls.

[chef1366]

Also make sure all the choke plungers are all the way back in when the choke if off.

[Flyboy]

Like a few guys have said, no biggie, I have ha it happen on more than one occasion, it is just the way of things, I also have an idea it is to do with the carbs.

[JEEPRUSTY]

Good article here should explain things:

http://roadstarclinic.com/content/view/56/96/

[boontonmike]

It would be cool to make a small baffle system like people put in their oil pans on autocross cars. Try and keep the fuel level in the bowl more consistant while pitched sideways or forward during braking. Porbably easier said then done though.

[first timer]

it's float bowl level, i had the issue as well. reset your floats to the higher end of the tolerance (higher float when upside down = lower fuel levels) see if that fixes it. Like Bill said check your rubber plungers too.

you might think it's livable but i can think of times when it would still be good to have a running bike after a hard stop.

[JEEPRUSTY]

So no one read the article I posted yet?
It explains what is happening.

[chuckycheese]

If it an't broke, don't fix it.

Of the many street motorcycles I've owned, I don't remember any that didn't exhibit the same phenomenon upon sudden braking so I'd be very reluctant to adjust anything.

Just get out and enjoy the weather. If you have to make a sudden stop and your bike dies....fire it back up and keep going!