Ah got it. Another thought, I recall someone mentioning taking their airbox off and finding the rubber intake boots were deformed and a lot of dirt build up on the intake / butterfly. Could be worth a look.
Joined Oct 2021
124 Posts | 65+
New Brunswick Canada
So it quits randomly and starts immediately or does it take a minute or two? Does it quit at slow speed or when braking for a stop sign or abruptly while at steady speed? Have you tried popping the filler cap after it dies to see if that makes a difference? Does it matter how much fuel is in the tank? Any other details you can think of?
There are 2 potentially related issues:
• It will stall when:
- You ride at moderately-slow speeds, then pull the clutch in and brake to a stop, like at a traffic light; or
- You're riding at moderate to moderately-slow speed and pull the clutch in to coast for a bit, like when hitting a lower speed zone (i.e. 50 MPH to 35 MPH).
Once did this when I pulled into a major intersection for a left turn. Wouldn't re-start (below), so I was stuck there when the lights changed. Not a good feeling.
Seems to happen more often on hot days (over 27°C / 80°F).
Once it starts occurring, it persists; I have to engine brake when slowing/stopping or risk a stall.
Tank is usually mid-level, not full, not empty. There is no indication that fuel level matters. I cannot tell if fuel brand matters.
• Hot starts are hard; it will crank but not catch. You have to open the throttle at least half-way before cranking, and hold it open several seconds after, or else it dies.
This happens >all< the time, including after stalling (above) and after fueling.
Happens on hotter and colder days. There is no indication that fuel level or fuel brand matters.
Cold starts are perfect, never any issue. Battery is great.
Bike is 2016, purchased with 3,500 km / 2,200 miles on the clock. All recalls / updates done. No codes, no indication anything is wrong. Had both issues on purchase.
Bone stock except:
• Charcoal canister removed; and
• Mild Rexxer remap.
Neither made any difference to either issue.
The hot start I can live with; the stalling is dangerous, I would very much prefer that get fixed.
Any suggestions are appreciated.
• It will stall when:
- You ride at moderately-slow speeds, then pull the clutch in and brake to a stop, like at a traffic light; or
- You're riding at moderate to moderately-slow speed and pull the clutch in to coast for a bit, like when hitting a lower speed zone (i.e. 50 MPH to 35 MPH).
Once did this when I pulled into a major intersection for a left turn. Wouldn't re-start (below), so I was stuck there when the lights changed. Not a good feeling.
Seems to happen more often on hot days (over 27°C / 80°F).
Once it starts occurring, it persists; I have to engine brake when slowing/stopping or risk a stall.
Tank is usually mid-level, not full, not empty. There is no indication that fuel level matters. I cannot tell if fuel brand matters.
• Hot starts are hard; it will crank but not catch. You have to open the throttle at least half-way before cranking, and hold it open several seconds after, or else it dies.
This happens >all< the time, including after stalling (above) and after fueling.
Happens on hotter and colder days. There is no indication that fuel level or fuel brand matters.
Cold starts are perfect, never any issue. Battery is great.
Bike is 2016, purchased with 3,500 km / 2,200 miles on the clock. All recalls / updates done. No codes, no indication anything is wrong. Had both issues on purchase.
Bone stock except:
• Charcoal canister removed; and
• Mild Rexxer remap.
Neither made any difference to either issue.
The hot start I can live with; the stalling is dangerous, I would very much prefer that get fixed.
Any suggestions are appreciated.
Joined Oct 2021
124 Posts | 65+
New Brunswick Canada
The first scenario sounds typical. Mine will stall at times when nearing a stop or cornering. It doesn't happen often and starts immediately. Others have mentioned that theirs will do this also. But it may not be a typical happenstance of the wonky fuelling as it may be another symptom of the problem that causes your second scenario. I had wondered if it happened more often at low fuel levels which would indicate a partially plugged fuel filter. I'm afraid i'm not much help as i'm new to this beast also. I bought mine last fall. A quick search on other forums turns up posts by other folks experiencing the same issue without any single solution. It looks like you may be into a bit of trial and error. One last question, when you hot start the bike, is it in neutral?
Joined Dec 2019
69 Posts | 11+
Brasília - DF - Brazil
Did you check the sidestand switch? It can cut off the engine randomly if it has a problem. You can bypass it and test it.
The bike is (usually) in neutral during hot starts. Doesn't seem to matter, but I will check that.
It is entirely possible that the stalling occurs only during low fuel situations. I will keep an eye on that, and try to check tank level when it happens. Maybe it really is as simple as a bad tank design leading to a fuel starvation situation on decel - engine braking would keep that from happening. Should be testable.
I recall an older Hypermotard stalling on me in a curve in Germany. Only happened once, I thought it was a fluke. Scared the $h!t out of me as I was hurtling towards a corner. Never thought to check the tank level then either, and my buddy (on an identical bike - same year, make, model) never had an issue. But I was slowing down at the time.
Hot starting is definitely not related to low fuel level, as it almost always occurs immediately after fueling. Mucho throttle allows it to catch, another 5 seconds of revving fixes it completely.
I would expect a bad sidestand switch to cause the bike to stall under throttle and/or at idle, and neither has ever happened.
Plus, if it really is intermittent, testing it doesn't necessarily prove anything. And it's unlikely we both / all have bad sidestand switches.
I would almost suspect a bad airflow sensor connection, or something similar. But I would think that would throw a code.
It is possible the air filter is clogged, I've not looked. But that doesn't really explain why it only occurs when the bike is hot in hotter weather, or what's going on with all the other "new" bikes that stall.
It is entirely possible that the stalling occurs only during low fuel situations. I will keep an eye on that, and try to check tank level when it happens. Maybe it really is as simple as a bad tank design leading to a fuel starvation situation on decel - engine braking would keep that from happening. Should be testable.
I recall an older Hypermotard stalling on me in a curve in Germany. Only happened once, I thought it was a fluke. Scared the $h!t out of me as I was hurtling towards a corner. Never thought to check the tank level then either, and my buddy (on an identical bike - same year, make, model) never had an issue. But I was slowing down at the time.
Hot starting is definitely not related to low fuel level, as it almost always occurs immediately after fueling. Mucho throttle allows it to catch, another 5 seconds of revving fixes it completely.
I would expect a bad sidestand switch to cause the bike to stall under throttle and/or at idle, and neither has ever happened.
Plus, if it really is intermittent, testing it doesn't necessarily prove anything. And it's unlikely we both / all have bad sidestand switches.
I would almost suspect a bad airflow sensor connection, or something similar. But I would think that would throw a code.
It is possible the air filter is clogged, I've not looked. But that doesn't really explain why it only occurs when the bike is hot in hotter weather, or what's going on with all the other "new" bikes that stall.
Joined Oct 2021
124 Posts | 65+
New Brunswick Canada
From my experience, clogged air filters will allow a vehicle to start and operate at low RPM's but lack the ablility to haul itself at higher rev's. Do you have the manufacturer's shop manual? I downloaded it from the HYPER FB page.
Joined Dec 2019
69 Posts | 11+
Brasília - DF - Brazil
Bad sensors do not always throw a code.
If the stalling happens during hot weather and hot engine it should be something sensor related.
Do the air and coolant temperature sensors read the right temperature?
The ECU sends less fuel on hot days to compensate for the decrease in air density. Did you check the injectors? Tried to clean them?
Do the MAP sensor readings make sense?
If the stalling happens during hot weather and hot engine it should be something sensor related.
Do the air and coolant temperature sensors read the right temperature?
The ECU sends less fuel on hot days to compensate for the decrease in air density. Did you check the injectors? Tried to clean them?
Do the MAP sensor readings make sense?
Currently having this problem, very unnerving! 20k miles, no evap canister. Stalls when leaving from a stop mostly like I'm not giving enough throttle (but I am). Also will sometimes stall when coming to a stop. I also have the Rexxer box so the TPS is reset.
@CPRICEIV: Sounds like we have the same issue.
@hyperbruno:
> Do the air and coolant temperature sensors read the right temperature?
Yes.
I considered getting a Rapid Bike Easy or installing another mod to let me mess with the air temperature reading, but I've not done it.
> The ECU sends less fuel on hot days to compensate for the decrease in air density. Did you check the injectors? Tried to clean them?
After 2k miles?
> Do the MAP sensor readings make sense?
I currently have no ability to to view MAP readings. If there is a logger for that, I've not heard of it.
@hyperbruno:
> Do the air and coolant temperature sensors read the right temperature?
Yes.
I considered getting a Rapid Bike Easy or installing another mod to let me mess with the air temperature reading, but I've not done it.
> The ECU sends less fuel on hot days to compensate for the decrease in air density. Did you check the injectors? Tried to clean them?
After 2k miles?
> Do the MAP sensor readings make sense?
I currently have no ability to to view MAP readings. If there is a logger for that, I've not heard of it.
> Do you have the manufacturer's shop manual? I downloaded it from the HYPER FB page.
No, I don't.
I don't understand "HYPER FB" and can't find it. Can you make it available?
[Edit]: Oh, I guess you mean Facebook. I'm not on Facebook.
No, I don't.
I don't understand "HYPER FB" and can't find it. Can you make it available?
[Edit]: Oh, I guess you mean Facebook. I'm not on Facebook.
Joined Oct 2021
124 Posts | 65+
New Brunswick Canada
Thank you, I appreciate that.
Does ScanM5x work on our bikes? I can't find which ECU we have. Mine is MY2016.
[Edit]: OK, I see the shop manual says I have a Marelli 7SM, so I guess ScanM5x does not work? Do we have to pony up for an OBDSTAR or something?
Does ScanM5x work on our bikes? I can't find which ECU we have. Mine is MY2016.
[Edit]: OK, I see the shop manual says I have a Marelli 7SM, so I guess ScanM5x does not work? Do we have to pony up for an OBDSTAR or something?
Joined Dec 2019
69 Posts | 11+
Brasília - DF - Brazil
A bike repair shop with Texa's diag tool can read the current sensor values that the ECU is reading.
Which probably does no good at all unless I strap the thing to the bike and take it for a spin - except it probably doesn't log, so I wouldn't be able to see what it's doing when the bike stalls out.
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