Yamaha FZ-09 Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
1,410 Posts
Discussion Starter #1
Hey all!

I'm having the very first issue with my bike after 147,000 kms.

Symptom: when on the throttle hard (wide open) the bike will not rev past about 8k. It's like hitting the rev limiter. This only happens when it's wide open or very close to it. I can run it to redline no problem in first gear, but throttle doesn't have to be wide open in first to hit redline.

Spark plugs and air filter are new this year. Approximately 10,000 kms on them.

Some have had accelerator position sensor issues. What were your symptoms?

Fuel pump does not make any strange noise.

Battery seems strong. Cranking for over 15 seconds without starting the bike, it still produces about 11 volts while cranking.

Any suggestions on where to start looking?

Sent from my SM-G973W using Tapatalk
 

·
Registered
Joined
·
19 Posts
Does it do it in all 3 modes? Has the ECU been flashed? The TPS is easy to check, it can be done through the display. The shop manual has the procedure, no tools needed. Look for any readings that seem out of wack at or near WOT. Some have found issues with condensation in the TPS wire connector. May also have something to do with the throttle servo.
 

·
Registered
Joined
·
1,389 Posts
What about a clogged fuel injector? That kinda makes sense since it's at high rpm it's not responding well and considering the miles/km you have.

Just a thought
 

·
Registered
Joined
·
248 Posts
Spark plugs and air filter are new this year. Approximately 10,000 kms on them.
Is there any chance you are using Iridium plugs? A guy on the FJ09/Tracer recently had the exact same issue after 8-10k kms on the iridium plugs. He swapped back to standard plugs and went for a test ride and immediately the bike would rev to redline like it should.
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #5
Does it do it in all 3 modes? Has the ECU been flashed? The TPS is easy to check, it can be done through the display. The shop manual has the procedure, no tools needed. Look for any readings that seem out of wack at or near WOT. Some have found issues with condensation in the TPS wire connector. May also have something to do with the throttle servo.
It does do it in all 3 modes. ECU has been flashed about 100,000 kms ago. Tps seems to check out using the diagnostic display.

Sent from my SM-G973W using Tapatalk
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #6
What about a clogged fuel injector? That kinda makes sense since it's at high rpm it's not responding well and considering the miles/km you have.

Just a thought
Possible...but I can get it to redline in first without going wide open. I have about 600 kms to do today to get home so maybe I'll throw some injector cleaner in it this morning.

Sent from my SM-G973W using Tapatalk
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #7
Is there any chance you are using Iridium plugs? A guy on the FJ09/Tracer recently had the exact same issue after 8-10k kms on the iridium plugs. He swapped back to standard plugs and went for a test ride and immediately the bike would rev to redline like it should.
Plugs are stock copper core. Maybe one is going bad early?

Sent from my SM-G973W using Tapatalk
 

·
Registered
Joined
·
1,389 Posts
Good luck on your ride home, stay safe
 
  • Like
Reactions: blkbrd

·
Registered
Joined
·
1,410 Posts
Discussion Starter #9
Good luck on your ride home, stay safe
Thanks. I think it'll be fine. This problem started late Sunday. I've ridden it close to 800 kms since.

Sent from my SM-G973W using Tapatalk
 
  • Like
Reactions: Crossbar1773

·
Registered
Joined
·
4,907 Posts
When did you change the fuel filter last? A blocked one will reduce fuel flow enough to kill high load/high rpm running.
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #11
When did you change the fuel filter last? A blocked one will reduce fuel flow enough to kill high load/high rpm running.
I have not changed the fuel filter ever. Never have seen one. Maybe it's in the tank?

Sent from my SM-G973W using Tapatalk
 
  • Like
Reactions: Crossbar1773

·
Registered
Joined
·
714 Posts
I would find someone that could check fuel pressure from the pump ,does it pull hard and then cut out ? Or just sort of taper off ?
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #13
Update: with the wife riding behind me, she can see raw gas coming out of the exhaust when it does this.

So that rules out a lack of fuel.

During a rest stop, I moved the rad forward to gain access to the coils and their connections. Pushed coils to make sure they're seated properly seated and also did the same for the electrical connections to the coils.

That SEEMED to fix it, but only temporarily. It pulled hard to redline in second and third gear several times at W.O.T.

Then it started doing it again but maybe not as bad. More investigation to come.

Sent from my SM-G973W using Tapatalk
 

·
Registered
Joined
·
1,410 Posts
Discussion Starter #14
I would find someone that could check fuel pressure from the pump ,does it pull hard and then cut out ? Or just sort of taper off ?
Just added an update CW, I'm beginning to think it's something with a plug or a coil. It's sort of a surging rather than a cut out.

Sent from my SM-G973W using Tapatalk
 

·
Registered
Joined
·
4,907 Posts
It's looking like it. You could fit new plugs first, but it might return as plug resistance increases with use. Then I'd look at the coils. Or you could save some faffing around and do both.
 
  • Like
Reactions: blkbrd

·
Registered
Joined
·
1,410 Posts
Discussion Starter #16
Update: On the last day of our trip the bike didn't miss a beat, so on Thursday I took a apart every connector I could find relating to fuel, throttle or spark. Cleaned every one of them with contact cleaner and put dielectric grease on the connections to prevent any dirt or water from getting into them.

Rode the bike Friday and it continued to have the same issue.

Yesterday I changed the plugs with spares I had on hand. Rode the bike all afternoon today and now it is flawless. It appears that a spark plug was bad.

Will update this thread if problem comes back.

Sent from my SM-G973W using Tapatalk
 
1 - 16 of 16 Posts
Top