Haybusa Parts and Service Member Support

Author Topic: fail safe mode?  (Read 121 times)

Offline Kuma

  • Apprentice Post Whore
  • **
  • Posts: 16
  • Enthusiast
fail safe mode?
« on: December 04, 2017, 12:48:21 AM »
Hey guys, I have a Gen 1 in a mini sand rsil, for some unknown reason it acts kinda like the Rev limiter it hitting at around 6500 rpm when under power.
Not sing any trouble codes, I was kinda hoping it was a bad fuel pump  but at idle ir is 43.
Is there a chance it is in the fail safe mode? Bing in the sand car it is diffeclut to check under load.  Being a sand car I can only check after hauling it to the dunes.

Online RansomT

  • Post Master
  • *****
  • Posts: 1101
  • Gender: Male
Re: fail safe mode?
« Reply #1 on: December 04, 2017, 08:29:24 AM »
Clutch Switch?
Fastest 1.5-Mile Pass - 252.222
Fastest 1-Mile Pass - 244.2997
Half Mile - 211.47
Fastest Nitrous Bike
Production Bike
211.079 LTA. P/P 1350

Offline Kuma

  • Apprentice Post Whore
  • **
  • Posts: 16
  • Enthusiast
Re: fail safe mode?
« Reply #2 on: December 04, 2017, 10:41:21 AM »
I have the clutch switch wired in as a momentary switch that I use as a started button, my keyed ignition switch has a momentary like a car, I have to crank that all the way clockwise and push the clutch momentary button to start.
it will not start without pushing the momentary button so I'm pretty confident that the clutch switch is disengaged while driving.

Online RansomT

  • Post Master
  • *****
  • Posts: 1101
  • Gender: Male
Re: fail safe mode?
« Reply #3 on: December 04, 2017, 06:13:51 PM »
Next then .... start the sand rail, while it is running disconnect the cam position sensor.  See if it will rev past 6500. When the cam position sensor gets weak it will mess with the ECU and cause a false limiter.  It is actually only used on start up and as a check against the crank position sensor while running.
Fastest 1.5-Mile Pass - 252.222
Fastest 1-Mile Pass - 244.2997
Half Mile - 211.47
Fastest Nitrous Bike
Production Bike
211.079 LTA. P/P 1350

Offline Kuma

  • Apprentice Post Whore
  • **
  • Posts: 16
  • Enthusiast
Re: fail safe mode?
« Reply #4 on: December 04, 2017, 06:45:54 PM »
pretty sure it will rev out when un loaded, it only when under load, like when driving I can only use about 1/8 to 1/4 throttle, I was hoping the fuel pump was not supplying enough fuel, that still could be it but when running in neutral it has 43 psi like it is supposed to.
I have my exhaust pipe, collector to muffler in the shop getting an O2 sensor bung mounted so I don't think I can run it tonight.
I'm going to the dunes after Christmas so really hoping to have this sorted out.

I was reading another post that the intake cam actually jumped a tooth, the guy had some of the same symptoms except he was getting codes, I have none :dunno: is that something common?

Online RansomT

  • Post Master
  • *****
  • Posts: 1101
  • Gender: Male
Re: fail safe mode?
« Reply #5 on: December 06, 2017, 05:33:57 AM »
Like my dear ol' dad would say, "check the simple stuff first".  If it isn't the clutch switch or cam sensor, then ... fuel pressure.  It can show 43 psi at idle and blipping the throttle, but under a load it can drop.  However, that condition usually doesn't act like a limiter, more like a bog then a miss. 
Which does lead it back to a cam issue or a crank position sensor issue.  Crank position sensor issue happens "typically" when the engine gets warm and the false limiter happens intermediately, but gets worse the warmer the engine.  If the intake cam has jumped a tooth and at idle the sensor signal is still within the ECU window, then no FI light.  But once again, unplugging the cam sensor will show if that is an issue.  The false limiter happens because the intake cam pin is in the wrong position, if it is too far off then it will also cause a FI light.


Just of giggles, how is your kickstand sensor and tip over sensor set up?
Fastest 1.5-Mile Pass - 252.222
Fastest 1-Mile Pass - 244.2997
Half Mile - 211.47
Fastest Nitrous Bike
Production Bike
211.079 LTA. P/P 1350

Offline Kuma

  • Apprentice Post Whore
  • **
  • Posts: 16
  • Enthusiast
Re: fail safe mode?
« Reply #6 on: December 06, 2017, 11:35:00 AM »
Kickstand switch is still on the wiring harness, I have the switch held down with a zip tie, I know it works because I have had the tie come loose and with the engine running, as soon as I put it into gear the engine dies, I would like to eliminate the switch if someone know how to do that, a simple jumper? I think it is more than that. the tip over switch is also still on the harness, I opened it up and filled it with silicone, I would also like to eliminate that also but I don't think that is something that can just be jumpered or unplugged either

Online RansomT

  • Post Master
  • *****
  • Posts: 1101
  • Gender: Male
Re: fail safe mode?
« Reply #7 on: December 06, 2017, 08:03:17 PM »
Kickstand switch can just be tied together (jumper).  Several folks, like Boost-by-Smith, make a plug in resistor that eliminates the tip-over.
Fastest 1.5-Mile Pass - 252.222
Fastest 1-Mile Pass - 244.2997
Half Mile - 211.47
Fastest Nitrous Bike
Production Bike
211.079 LTA. P/P 1350