Is it possible to stall a semi-automatic motorcycle? - Because I somehow did this morning and nearly caused an accident ????‍♂️

[mattk1]

Hi everyone,

I have been living in Thailand for just over 3 months now and have got myself a Yamaha Finn 115i semi-automatic motorcycle.

I've been using this motorcycle trouble free for well over 6 weeks now but this morning something happened which really but the frighteners up me.

I was stopped at a red light waiting to turn right, lots of other motorcycles and cars behind me etc, light turns green and I'm already in 1st and pull away, I selected 2nd gear after just taking off and suddenly my motorcycle came to a dead stop, throwing me forward like as though I had stalled it and the motorcycle behind rammed straight into my number plate and rear lights ???? number plate all bent and lights pushed up but nothing major.

 

Luckily he was ok and so was I but it's really knocked my confidence and I am trying to understand what happened - maybe some of you more experienced riders can help?

 

I feel as though I might have selected 2nd gear a bit too early after the lights turned green but I was told that these semi-automatic motorcycles can't stall, as you can leave them in any gear with the engine running etc. So what on earth did I do wrong this morning?? ????‍♂️

 

I keep thinking how lucky that it wasn't a big car or a coach that rammed into me, man I would've been flattened ????

 

Thanks in advance

[scubascuba3]

Have you got the Idling stop switch set to on? where engine goes off when you come to a stop and starts when you use the throttle?

[mattk1]

5 minutes ago, scubascuba3 said:

Have you got the Idling stop switch set to on? where engine goes off when you come to a stop and starts when you use the throttle?

Hi Scuba,

 

I don't have that feature on my motorcycle, it's quite a basic machine ????

[scubascuba3]

Sounds like selecting 2nd gear too early was to blame, I don't know whether stalling is meant to be impossible

[mattk1]

1 minute ago, scubascuba3 said:

Sounds like selecting 2nd gear too early was to blame, I don't know whether stalling is meant to be impossible

It's the only thing I can think back of that might be the cause, it was a very weird thing to happen and caught me completely out of the blue ????‍♂️

[scubascuba3]

12 minutes ago, mattk1 said:

It's the only thing I can think back of that might be the cause, it was a very weird thing to happen and caught me completely out of the blue ????‍♂️

I had a similar scary incident when my Click decided to stall when my Idling stop kicked in when i was about to turn right on Pattaya 3rd road almost in the path of a car doing 40+kph, never used it after

[Peterw42]

OP, it may well have been a bit of dirt/water in fuel. Have you been filling up from the 30 baht Hong thong bottles lately ?

Water in fuel can be deceptive as when you are just pottering around you don't notice it, but when you rapidly open the throttle it has a dramatic effect.

[Lacessit]

It's possible to stall most vehicles, two or four wheel, if too high a gear is selected when starting from a standstill.

I would suggest taking the scooter to a traffic-free area, and testing it in higher gears to see if the fault can be replicated.

One possible cause in older scooters is the accelerator cable is sticking, so there are not enough revs to get moving. Have the bike checked by a competent mechanic.

[mattk1]

11 minutes ago, Peterw42 said:

OP, it may well have been a bit of dirt/water in fuel. Have you been filling up from the 30 baht Hong thong bottles lately ?

Water in fuel can be deceptive as when you are just pottering around you don't notice it, but when you rapidly open the throttle it has a dramatic effect.

Hi Peter, thanks for your reply, I only ever fill up at PTT stations but good suggestion and something I was not aware of ????????

 

9 minutes ago, Lacessit said:

It's possible to stall most vehicles, two or four wheel, if too high a gear is selected when starting from a standstill.

I would suggest taking the scooter to a traffic-free area, and testing it in higher gears to see if the fault can be replicated.

One possible cause in older scooters is the accelerator cable is sticking, so there are not enough revs to get moving. Have the bike checked by a competent mechanic.

Thanks Lacessit, good idea to try and recreate the problem, just would love to understand exactly what happened so I can make sure I don't do it again ????

 

Re the accelerator cable, the bike is less than a year but I will have it checked out regardless, thanks again ????????

[KhunBENQ]

I rarely use 1st gear on my Honda Wave.

2nd gear takes me (80 kg) away smoothly and no need to change gear for quite a distance.

Would always take me across an intersection.

[KhunBENQ]

Of course an underlying problem with dirty/inferior fuel is possible.

I had problems with the motor stall just after starting and trying to get off.

In the end the fuel pump had to be replaced.

Was clogged with some dirt or so (mechanic showed me).

Wasn't too cheap, 1800.

From the OP it sounds like a problem with fuel supply.

[mattk1]

41 minutes ago, KhunBENQ said:

I rarely use 1st gear on my Honda Wave.

2nd gear takes me (80 kg) away smoothly and no need to change gear for quite a distance.

Would always take me across an intersection.

Hi KhunBENQ, thanks for your replies, I'm also around 80kg so I will give it a try taking off in 2nd ????

 

21 minutes ago, KhunBENQ said:

Of course an underlying problem with dirty/inferior fuel is possible.

I had problems with the motor stall just after starting and trying to get off.

In the end the fuel pump had to be replaced.

Was clogged with some dirt or so (mechanic showed me).

Wasn't too cheap, 1800.

From the OP it sounds like a problem with fuel supply.

This is also sounding like good advice, I've been transfixed on the idea that I somehow stalled the bike with my own doing but in the case of a fuel supply issue it could cause this to happen ????

[Lacessit]

23 minutes ago, KhunBENQ said:

Of course an underlying problem with dirty/inferior fuel is possible.

I had problems with the motor stall just after starting and trying to get off.

In the end the fuel pump had to be replaced.

Was clogged with some dirt or so (mechanic showed me).

Wasn't too cheap, 1800.

From the OP it sounds like a problem with fuel supply.

 

1 hour ago, Peterw42 said:

OP, it may well have been a bit of dirt/water in fuel. Have you been filling up from the 30 baht Hong thong bottles lately ?

Water in fuel can be deceptive as when you are just pottering around you don't notice it, but when you rapidly open the throttle it has a dramatic effect.

Dirt is a more likely cause.

91 and 95 octanes nowadays contain appreciable amounts of ethanol. With water, the binary combination of hydrocarbon and ethanol forms a ternary mixture in a single liquid phase, so the fuel is able to tolerate some water without affecting performance.

All bets are off if the water present exceeds the limits of miscibility, as a couple of unscrupulous sellers have found out, when they added water to their stock of gasoline to increase their profit. That's far more likely to happen at village pumps than at volume highway stations, though.

[Orinoco]

So its a second hand bike you have ?

Have you checked if it has the correct level of oil in the engine.

A semi automatic should not do what you described.

 

 

 

 

[KhunLA]

user error

[richard_smith237]

17 minutes ago, KhunLA said:

user error

Outstanding input...  extremely helpful....  

 

 

Its a semi-auto... so if a higher gear is selected too early the auto-clutch engages preventing the stall. 

In this case it seems the auto-clutch didn’t engage properly, not only resulting in a stall, but the gear engaged and locked up the rear-wheel - just like applying the rear brake full on !!!...   Quite dangerous and should definitely not happen.

 

Thus: the fuel suggestion is a valid one (check the fuel filter)...  The recommendation to go to a quiet area and re-create the issue is also a good idea. 

 

There could be an issue with the auto-clutch itself.

 

 

 

 

 

[papa al]

If the failure was intermittent or transient,

then H2O prob more likely than dirt.

Look in the tank w/ a flashlight to see

if a blob of water/Etol in solution 

is separated on bottom of tank.

If so have mech remove it.

Normally would expect this prob

only with a bike that has been stored.

Don't worry.

... unless your karma is the prob.

 

[Phnom Penh Trader]

You stalled the unstallable a bit like the Titanic and sinking the unsinkable good job!

[Gsxrnz]

If the rear wheel locked up to the extent the OP states, it probably wasn't a stall.  A stall results in normal deceleration, even on a semi-auto.

 

OP - it's probable that your transmission locked up because the gears didn't mesh correctly at the shift. Difficult to achieve, but can be done. Particularly if you did a slow stab of the pedal and the shift is made too early.

 

 

[Orinoco]

Not a fuel issue.

Does a semi auto scooter lock the back wheel up if you run out of fuel !!!!!!!! no

it free wheels.

Oil level or auto clutch/gear box issue.

Is it a Somchai, bit's-a bike special, .bits off this bits off that, now sold to Falang ?

Op has not said anything about the bikes history.

 

 

 

[Phnom Penh Trader]

2 hours ago, Gsxrnz said:

If the rear wheel locked up to the extent the OP states, it probably wasn't a stall.  A stall results in normal deceleration, even on a semi-auto.

 

OP - it's probable that your transmission locked up because the gears didn't mesh correctly at the shift. Difficult to achieve, but can be done. Particularly if you did a slow stab of the pedal and the shift is made too early.

 

 

You are obviously blissfully unaware but a motorbike has a constant mesh gearbox,as opposed to cars which use synchro mesh gearboxes so that cannot possibly happen?

[VocalNeal]

I'm thinking the OP pulled away in 2nd and then selected first in error.

[richard_smith237]

26 minutes ago, VocalNeal said:

I'm thinking the OP pulled away in 2nd and then selected first in error.

Would selecting a lower gear stall the bike or cause it to slow at higher revs ?

[richard_smith237]

3 hours ago, Gsxrnz said:

If the rear wheel locked up to the extent the OP states, it probably wasn't a stall.  A stall results in normal deceleration, even on a semi-auto.

IF it stalls in gear, there is no power to drive the engine... the engine doesn't 'free-wheel' at low speeds, it just locks - thats why we can’t push a bike which is in gear (on or off).

 

 

As others have pointed out, it would be helpful to know what sort of bike this is.

At the moment I’m guessing its something like a 15 year old Honda Click....   I don't know if semi-automatic scooters are still sold. 

 

[seedy]

On 12/2/2022 at 5:23 PM, mattk1 said:

I have been living in Thailand for just over 3 months now and have got myself a Yamaha Finn 115i semi-automatic motorcycle.

 

28 minutes ago, richard_smith237 said:

At the moment I’m guessing its something like a 15 year old Honda Click....   I don't know if semi-automatic scooters are still sold.

You mean Honda Waves are not sold anymore - they are semi auto !!! 555

[eisfeld]

3 hours ago, richard_smith237 said:

As others have pointed out, it would be helpful to know what sort of bike this is.

At the moment I’m guessing its something like a 15 year old Honda Click....   I don't know if semi-automatic scooters are still sold. 

 

He iterally told the model in the first sentence ????

Semis are still sold in huge numbers, plus Clicks were always fully auto.

[richard_smith237]

13 minutes ago, eisfeld said:

He iterally told the model in the first sentence ????

Semis are still sold in huge numbers, plus Clicks were always fully auto.

My bad - I somehow missed that Part... so its a Yamaha Finn 115..

 

3 hours ago, seedy said:

You mean Honda Waves are not sold anymore - they are semi auto !!! 555

I didn’t know if ‘semi-autos’ are sold any more.... It's not something I ever considered.

 

--------

 

Based this its not a 15 year old bike...   has the Op successfully recreated the stalling issue ? (i.e. in a quiet car-park?)..

 

 

[Orinoco]

Foot in mouth syndrome is on the rise around this. 

forum. 

 

 

[mattk1]

On 12/2/2022 at 7:57 PM, Lacessit said:

Dirt is a more likely cause.

91 and 95 octanes nowadays contain appreciable amounts of ethanol. With water, the binary combination of hydrocarbon and ethanol forms a ternary mixture in a single liquid phase, so the fuel is able to tolerate some water without affecting performance.

All bets are off if the water present exceeds the limits of miscibility, as a couple of unscrupulous sellers have found out, when they added water to their stock of gasoline to increase their profit. That's far more likely to happen at village pumps than at volume highway stations, though.

Thanks Lacessit ????????

 

On 12/3/2022 at 12:05 PM, Orinoco said:

So its a second hand bike you have ?

Have you checked if it has the correct level of oil in the engine.

A semi automatic should not do what you described.

Hi Orinoco, it's not a second hand bike, it was bought brand new by my missus ????

Oil level checked today based on your reply, and can confirm it is correct level ????

Thanks for your input

 

On 12/3/2022 at 12:16 PM, KhunLA said:

user error

????????

 

On 12/3/2022 at 12:38 PM, richard_smith237 said:

Outstanding input...  extremely helpful....  

 

 

Its a semi-auto... so if a higher gear is selected too early the auto-clutch engages preventing the stall. 

In this case it seems the auto-clutch didn’t engage properly, not only resulting in a stall, but the gear engaged and locked up the rear-wheel - just like applying the rear brake full on !!!...   Quite dangerous and should definitely not happen.

 

Thus: the fuel suggestion is a valid one (check the fuel filter)...  The recommendation to go to a quiet area and re-create the issue is also a good idea. 

 

There could be an issue with the auto-clutch itself.

 

Hi Richard, thanks a lot for your input. I will have the bike checked out for sure and the fuel filter etc and up to now I haven't been able to re-produce what happened but I will keep trying in my apartment car park every morning ????????

 

 

13 hours ago, papa al said:

If the failure was intermittent or transient,

then H2O prob more likely than dirt.

Look in the tank w/ a flashlight to see

if a blob of water/Etol in solution 

is separated on bottom of tank.

If so have mech remove it.

Normally would expect this prob

only with a bike that has been stored.

Don't worry.

... unless your karma is the prob.

 

Hi papa al, thankd for your reply ???? yeah the bike has been in daily use from brand new so really not sure. I'm still swaying towards the 'user error' post earlier ????  

 

13 hours ago, Phnom Penh Trader said:

You stalled the unstallable a bit like the Titanic and sinking the unsinkable good job!

Hi Phnom Penh, I think you might be right ????????

 

12 hours ago, Gsxrnz said:

If the rear wheel locked up to the extent the OP states, it probably wasn't a stall.  A stall results in normal deceleration, even on a semi-auto.

 

OP - it's probable that your transmission locked up because the gears didn't mesh correctly at the shift. Difficult to achieve, but can be done. Particularly if you did a slow stab of the pedal and the shift is made too early.

Hi Gsxrnz, thanks for your reply ???? Good to hear that it can be done, like I said I feel I shifted too early and it just took my by surprise the way it just stopped so suddenly ????‍♂️

 

10 hours ago, Orinoco said:

Not a fuel issue.

Does a semi auto scooter lock the back wheel up if you run out of fuel !!!!!!!! no

it free wheels.

Oil level or auto clutch/gear box issue.

Is it a Somchai, bit's-a bike special, .bits off this bits off that, now sold to Falang ?

Op has not said anything about the bikes history.

 

Hi Orinoco, sorry for the slow reply here, it was bought brand new by my missus and has only ever been used by her or myself ????????

 

10 hours ago, Phnom Penh Trader said:

You are obviously blissfully unaware but a motorbike has a constant mesh gearbox,as opposed to cars which use synchro mesh gearboxes so that cannot possibly happen?

????????

 

10 hours ago, VocalNeal said:

I'm thinking the OP pulled away in 2nd and then selected first in error.

Hi VocalNeal, thanks for your reply, definitely pulled away in 1st, I have OCD about being in 1st gear at lights ????

 

9 hours ago, richard_smith237 said:

Would selecting a lower gear stall the bike or cause it to slow at higher revs ?

????????

 

9 hours ago, richard_smith237 said:

IF it stalls in gear, there is no power to drive the engine... the engine doesn't 'free-wheel' at low speeds, it just locks - thats why we can’t push a bike which is in gear (on or off).

 

 

As others have pointed out, it would be helpful to know what sort of bike this is.

At the moment I’m guessing its something like a 15 year old Honda Click....   I don't know if semi-automatic scooters are still sold. 

 

Hi Richard, thanks for your reply, it's a Yamaha Finn 115i, very basic machine owned from new by my missus I think less than a year old ????????

 

9 hours ago, seedy said:

 

You mean Honda Waves are not sold anymore - they are semi auto !!! 555

????????

 

5 hours ago, eisfeld said:

He iterally told the model in the first sentence ????

Semis are still sold in huge numbers, plus Clicks were always fully auto.

????????

 

5 hours ago, richard_smith237 said:

My bad - I somehow missed that Part... so its a Yamaha Finn 115..

 

I didn’t know if ‘semi-autos’ are sold any more.... It's not something I ever considered.

 

--------

 

Based this its not a 15 year old bike...   has the Op successfully recreated the stalling issue ? (i.e. in a quiet car-park?)..

 

 

Hi richard, thanks for your reply, I still haven't been able to recreate the issue but keep trying to do so in my apartment car park ????????

 

1 hour ago, Orinoco said:

Foot in mouth syndrome is on the rise around this. 

forum. 

 

 

????????

[papa al]

5 hours ago, richard_smith237 said:

My bad - I somehow missed that Part... so its a Yamaha Finn 115..

 

I didn’t know if ‘semi-autos’ are sold any more.... It's not something I ever considered.

 

--------

 

Based this its not a 15 year old bike...   has the Op successfully recreated the stalling issue ? (i.e. in a quiet car-park?)..

 

 

Semi-auto = auto-clutch.