Cant rev passed 8000-9000 rpms.....? Any ideas

You are very observant indeed!!! The bike was not getting charged, upon closer look one the wires that goes from stator to the rectifier has been rubbing against the frame and I could see the bare wire- figure it could have shorted out. Now I tested the rectifier with the voltmeter and it seem to be ok. I suspect it is the stator that went out. I put battery on trickle charge and some day this week will check stator. Ohh well they lasted 4 years

 

stators blow out if any wires touch each other or ground.

 

Wanted to bring the update on the blown out crispy stator!!! It smelled very toasty. Bottom line new one was put in place. Relocated rectifier to the front side fairing where it gets more airflow and away from the exhaust pipes where it used to be more confined to the heat. Thank you all!!! Time to ride, happy riding!!

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The old filter you took out looks like a K&N, it might be worth a few pesos to someone looking for one. They go for $40+ new. Since they’re reusable, all someone needs to do is clean and oil it.

 

One other note on the air filter. The K&N filter requires removal of the air box o-rings for it to fit properly. Double echeck to see if those are missing. It might not make a difference but thought I’d point that out.

 

Thanks Ottablue for taking time to provide an update on how the isssue was resolved.

Feedback like this really helps VFR owners build and share knowledge of what to look out for, and may help others diagnose what may be affecting their bike.


From the crispy windings in those photois, it looks like two of the three stator phases have shorted out.

Whilst you have already fitted a new stator, you may want to consider getting the old stator rewound to retain as a spare. Obtaining parts for earlier VFRs is becoming problematic and if you intend keeping the bike long term you may eventually need a serviceable spare.


With hindsight - at least in your specific case - I can now understand the link between the limited revs problem which you reported and a dying stator.

Unlike most 5th Gens you had already fitted a decent MOSFET RR so when phases in the stator shorted out, provided there was AC still appearing on at least one leg of the stator then the the MOSFET RR was still able to supply some power to the bike. But as power demands from the coil packs rise with engine revs, that limited power supply will eventually be exceeded and will place an effective limit on the RPM the bike would rev to. I just hope your Yamaha RR was not damaged by running with a faulty stator.

Most 5th Gens fitted with the stock RR are unlikely to encounter those symptoms. Once one or more phases dies on a stator, it causes the stock RR to work continuosly at max output mode to try and feed sufficient power, but they are far less robust RRs and extended running at max output will cause diodes inside the RR to overheat and fail, then once the remaining energy left in the battery is drained, riders end up stranded and often spot weird behaviours like of clocks resetting or dash display failing shortly before the bike shuts down.

SkiMad

 

OOTV, You are 100% right it turned out to be K@N filter which I was not aware of and per your statement it is reusable!!! If I was not lazy I should of looked first before ordering OEM filter. I will wash it out and have it for the time New filter gets dirty! Ofcourse if I remember to check

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Very thorough and insightful sum up of the events that I have been dealing here with!!! While reading it made me better understand few things that rectifier can compensate if one of stator phases is out. That brings me to install new rectifier which I bought but did not install still used the old one. My voltage with old rectifier under load 13.3v with the radiator fans running and bike idling. When revved passed 5k rpms voltage goes up to 14v. Thanks for the reply!!!

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You should be able to find K&N cleaning/oiling kits at just about any motorcycle shop or a Cycle Gear. Although I don't know if they use anything proprietary in their cleaners or oil, it shouldn't be hard to determine what's in their formula and buy something generic, as I'm sure they charge a little more for their kits than other off the shelf solutions.

 

Save a bunch of money and get it from Walmart or Amazon. Bike Shops tend to sell them for a lot more.

 

Good call, although I would imagine their cleaner isn’t anything more than an off the shelf cleaner, something like Simple Green, would probably be safe to say that their oil isn’t anything special either but don’t know what their gauze material is sensitive to.

 

Their oil isn't necessarily anything special, but it is a lot stickier than regular oil you have hanging around.