Sudden power loss

[David Alger]

I was 10 minutes into a ride yesterday at about 60 mph and suddenly the bike slowed down….i mean REALLY slowed down to 10 mph. I shifted down to 3rd and no help. Then i disengaged the clutch and engine reved normally. Tried several times and after about five minutes time I was able to proceed with no problems engine running smooth no missing no backfiring nothing. It ran perfectly for the rest of the day. I have had that same thing happened twice and both times it was after about 10 minutes of driving the bike to slowed down to very slow speed and there was nothing I can do to make it go faster.

I’m hoping one or more of you have had this happen and would let me know what if anything was done to correct the problem.

 

[RossKean]

What year?
Might be coils, fuel pump, TPS, battery connection, injector, water in fuel...
GenII spider bite?

Has it happened before or since?

 

[mcatrophy]

Fuel tank air inlet? Check by stopping next time it does it and opening the filler cap, does it suck in air?

 

[escapefjrtist]

You indicate the engine revved normally but the bike wouldn't speed up? A few more details will help us help you.

~G

 

[RossKean]

You indicate the engine revved normally but the bike wouldn't speed up? A few more details will help us help you.

~G

I didn't get that from what the OP said but if so, it is a very different problem - clutch slipping, perhaps.

 

[MotoMike]

You indicate the engine revved normally but the bike wouldn't speed up? A few more details will help us help you.

~G

In the original post David Alger stated: "Then i disengaged the clutch and engine reved normally."

 

[MotoMike]

You might want to look at this: https://motorcyclelatest.com/why-is-motorcycle-losing-power-when-accelerating-fix/

 

[David Alger]

What year?
Might be coils, fuel pump, TPS, battery connection, injector, water in fuel...
GenII spider bite?

Has it happened before or since?

Thanks, it's a 2016 and it only happened twice. Strang thing is that when I disengaged the clutch , engine reved up normally , then engaging clutch, very little power

 

[Pjotr]

I was 10 minutes into a ride yesterday at about 60 mph and suddenly the bike slowed down….i mean REALLY slowed down to 10 mph. I shifted down to 3rd and no help. Then i disengaged the clutch and engine reved normally. Tried several times and after about five minutes time I was able to proceed with no problems engine running smooth no missing no backfiring nothing. It ran perfectly for the rest of the day. I have had that same thing happened twice and both times it was after about 10 minutes of driving the bike to slowed down to very slow speed and there was nothing I can do to make it go faster.

I’m hoping one or more of you have had this happen and would let me know what if anything was done to correct the problem.

It sounds more like a transition from idling/cold engine management to closed loop management by ecu. Did you turn of the bike completely (key to off position) when it occurred and then restarted? Problem is as many others already mentioned there can be many reasons, albeit not to be expected from a 2016 model.

 

[David Alger]

It sounds more like a transition from idling/cold engine management to closed loop management by ecu. Did you turn of the bike completely (key to off position) when it occurred and then restarted? Problem is as many others already mentioned there can be many reasons, albeit not to be expected from a 2016 model.

Thanks, I will try the ignition switch thing if it happens again. Also, there were no lights that came on in the dash.

 

[Wizard37]

Had this once. Check the side stand switch for function. Lube the crap out of it to keep water out and the lube oxidizing. It does get warm near the pipes. Took me a long time to figure it out.
The other issue was the small bore supplemental air pipes getting clogged. Easy to remove and rinse in gas. (2007 at 70k).
Hope this helps
Peter

 

[David Alger]

Had this once. Check the side stand switch for function. Lube the crap out of it to keep water out and the lube oxidizing. It does get warm near the pipes. Took me a long time to figure it out.
The other issue was the small bore supplemental air pipes getting clogged. Easy to remove and rinse in gas. (2007 at 70k).
Hope this helps
Peter

Yes thought about the side stand switch, but the engine was still running, I think that switch would cut off the power totally, wouldn't it? When disengaging the clutch, the engine reved up to full RPMs Weird

 

[RossKean]

Had this once. Check the side stand switch for function. Lube the crap out of it to keep water out and the lube oxidizing. It does get warm near the pipes. Took me a long time to figure it out.
The other issue was the small bore supplemental air pipes getting clogged. Easy to remove and rinse in gas. (2007 at 70k).
Hope this helps
Peter

Are you referring to the rubber hose(s) that go to the intake air pressure sensor? This was a fairly common Gen II issue but not later years. (It would also throw a fault code 14).
Side stand switch is unlikely to cause reduced power but will kill the engine if it thinks the stand is down. Maybe the switch is making spotty contact - power would come back when clutch is pulled. Seems unlikely to me but a clean and lube wouldn't hurt anything.

Still sounds like crappy fuel (any water in the tank?) or an intermittent coil. Check the tank for water/rust/dirt with a bright penlight. As mcatrophy mentioned, possibly a tank vent issue (or crimped fuel line). Did you do any work on the bike recently?

 

[Prosolar]

I agree with Wizard, side stand switch issue will cut power unless the clutch is in or it's in neutral...

 

[David Alger]

Are you referring to the rubber hose(s) that go to the intake air pressure sensor? This was a fairly common Gen II issue but not later years. (It would also throw a fault code 14).
Side stand switch is unlikely to cause reduced power but will kill the engine if it thinks the stand is down. Maybe the switch is making spotty contact - power would come back when clutch is pulled. Seems unlikely to me but a clean and lube wouldn't hurt anything.

Still sounds like crappy fuel (any water in the tank?) or an intermittent coil. Check the tank for water/rust/dirt with a bright penlight. As mcatrophy mentioned, possibly a tank vent issue (or crimped fuel line). Did you do any work on the bike recently?

Thanks, no haven't done any work on it since the 2nd gear recall. There was a second recall after the 2nd gear on for a software issue, but I haven't done that one as yet

 

[David Alger]

I was 10 minutes into a ride yesterday at about 60 mph and suddenly the bike slowed down….i mean REALLY slowed down to 10 mph. I shifted down to 3rd and no help. Then i disengaged the clutch and engine reved normally. Tried several times and after about five minutes time I was able to proceed with no problems engine running smooth no missing no backfiring nothing. It ran perfectly for the rest of the day. I have had that same thing happened twice and both times it was after about 10 minutes of driving the bike to slowed down to very slow speed and there was nothing I can do to make it go faster.

I’m hoping one or more of you have had this happen and would let me know what if anything was done to correct the problem.

Thank you everyone for the comments and suggestions. I had the second recall done which was a re flashing of the ECU. Have not had the issue since. Ride Now called yamaha and they agreed that that was probably the problem. I'll update if it occurs again.

 

[RossKean]

While I heard that some people had issues with a low rev. limiter in 2nd gear after the initial re-flash was done in conjunction with the recall, I have never heard of the sort of power loss you described. Hopefully, this is a permanent fix for you.