Loss of power at top end of Suzuki Gladius 650

[Ehcbr125]

Hi guys, it’s me again.

The other day me and my partner were out on the Gladius. He was in 4th gear. Accelerated and changed into 5th. We lost almost all power as if it had gone into limp home mode. Then the power seemed to come back on its own. Without switching the bike off and on. It’s also happened once before when I was riding it. Literally yanking the throttle back and nothing happens. I’ve spoken to my guy at the garage and he will take a look but he seemed stumped to so I thought I would ask on here to see if you guys had anything similar and found out what the problem was. As I said this has happened twice but that been over the space of a year.

Thanks in advance

[WD-40]

Is there anything under the seat that could be covering the air box inlet?

[Ehcbr125]

Is there anything under the seat that could be covering the air box inlet?

 

Hmm hadn’t considered that but looking into we think the air filter is due a change. So maybe start with that then

[Stu]

Was it as if the ignition was turned off then back on?

Suzuki electrics aren't the best!

[Ehcbr125]

Was it as if the ignition was turned off then back on?

Suzuki electrics aren't the best!

 

I suppose you could compare it to that but everything stayed on, lights, dash etc. It’s fuel injected but I guess it would be similar to if your carbs needed a clean.

Literally could open it full throttle and nothing happened. Came down to about 30mph then picked back up again. It’s really odd.

[Mississippi Bullfrog]

That sounds like fuel starvation to me.

[onesea]

Its the old riddle..

Fuel - Water/ Dirt in tank/ filter/ fuel hose / fuel pump - I always start with fuel additives and a hot run.

Air - Often loss of power over time but could be airflow momentarily stopped.

Spark - Electrical always nightmare. Sounds like across all cylinders so unlikely to be plugs or leads (but could be losing power on 2 cylinders ?Coil again normally brake down over time so problem might get worse), timing pickups, throttle control?

Did it happen after changing gear both occasions? Did the power come back when you eased the throttle? or did it leap to full throttle with it wide open?

Any fault lights, even momentarily?

[Ehcbr125]

Its the old riddle..

Fuel - Water/ Dirt in tank/ filter/ fuel hose / fuel pump - I always start with fuel additives and a hot run.

Air - Often loss of power over time but could be airflow momentarily stopped.

Spark - Electrical always nightmare. Sounds like across all cylinders so unlikely to be plugs or leads (but could be losing power on 2 cylinders ?Coil again normally brake down over time so problem might get worse), timing pickups, throttle control?

Did it happen after changing gear both occasions? Did the power come back when you eased the throttle? or did it leap to full throttle with it wide open?

Any fault lights, even momentarily?

 

Hi thanks for your reply. You’ve made me curious as today after a short run something new and odd happened. Normally the bike pulls at 7mph in gear 1 with no throttle and no clutch but today it pulled at 12mph. Could this tie in with the throttle control you mentioned?

[Ehcbr125]

That sounds like fuel starvation to me.

 

This is what we thought until the new thing as mentioned in the comment above happened.

[Mississippi Bullfrog]

That sounds like fuel starvation to me.

 

This is what we thought until the new thing as mentioned in the comment above happened.

 

Bear in mind that the engine management will vary that effect depending on ambient weather conditions. The difference between 7mph and 12mph at no throttle input isn't huge.

[onesea]

Hi thanks for your reply. You’ve made me curious as today after a short run something new and odd happened. Normally the bike pulls at 7mph in gear 1 with no throttle and no clutch but today it pulled at 12mph. Could this tie in with the throttle control you mentioned?

 

I am no expert on faults but...

Given your fault running at higher revs, that could be the electronic choke? Did it stop when the bike warmed up?

I am thinking sensor problem? occasional faulty reading or dodgy wiring.

Google is often your friend and clever people on forums (which I don't class myself as), research several times and look for the actual symptoms before ripping anything apart or ordering parts.

Some sensors can be tested with voltmeters and resistance, others by disconnecting.

[Ehcbr125]

It’s really hard to pin point it while looking online. Plus there doesn’t seem to be a huge amount of information on the Gladius. Spoke to my guy at the garage and he’s said as it’s intermittent it’s hard to run tests on it as if it doesn’t have the symptoms he won’t be able to find the problem. Going out today so will see how she runs.

[Mississippi Bullfrog]

It might be worth getting an additive to make sure there's no water in the fuel. Droplets can sit in the tank and cause intermittent power loss issues. Shouldn't happen with the Ethanol in petrol these days but you can still get dud fuel on occasions.

We used to put a small amount of meths into the tank which absorbs the water (as the Ethanol should) and it can then be burnt.

[Ehcbr125]

Thank you I will give this a go. Going to post again as something new is happening now!