Did you try adjusting the idle screw?

There will not be any tappet sound because of very minimum clearances you had put. In r15 engine, there is very slight tappet noise which is very obvious for a new bike also. So get it checked from a service center soon, otherwise slightly tightened tappet setting can start damaging the valve stem or push rod. A good valve setting breaths easily, not like 1100-1200rpm, it will be 1400+-50rpm.

I cant adjust..its a different type of screw..can i buy that tool from service centre ?



i'm very happy that a healthy debate is going on.. new lessons learned from you bros..anyway next saturday i'm gonna consult with service centre..all nearby yamaha service centres are bullshit..

Guys a piece of advice. If your bike has run considerable kms or is more than 2 years old I would suggest changing pistons for the front brakes or the oil seals atleast if you feel the pistons are fine. My front brake was seizing after a couple of liberal dosage to the front brake and please use rubber grease for lubing your sliders and calliper boots. Rubber grease is expensive another cheap alternative is dalda ghee. Never ever use bearing grease on rubber parts. They become hard and crack and will lead to rusting of the slider pins.
Most of the morons in SVC use normal grease for lubing rubber parts.
CHEERS

Did you try adjusting the idle screw?

Indeed, Raza. Bearing greases aren't at all recommended other than high friction roller contact types. Unfortunately, I've seen mechanics just dab a finger of, black goop and handsomely dab on whatever and whenever they can. Secondly, a small correction, greasing doesn't attract rust, be it bearing or silicone, they prevent oxidation to an extent as long as they aren't dried. But, rest you're pretty much spot on, and I am still not able to find that ever evanescent silicone or red rubber grease here. I'd definitely like to get a dubba from you.



Whenever I hear IDLE SCREW related to R15, you're the only devil that comes to my mind.

Cheers!
VJ

Hey guys My front Tyre is due for a change. What are the effects of upsizing(100/90) /downsizing(80) in riding Dynamics? Pls shed some light on this and as well as the rear Tyre.

Did you try adjusting the idle screw?

[MENTION=78129]Maverick_BOSS[/MENTION]
Hey man, Good time to change the tyres now that monsoon is mostly been dealt with!

We have shed some light on this topic as it was raised by another fellow rider [MENTION=62910]aditya_YZF-R15[/MENTION] in the previous week. If you may scroll just a few pages back (Page 1282) on this thread. Refer to my post #12818 . Hope the info could be helpful.

But to sum it up. Try not to upsize/downsize the Front wheel. There are more chances of handling going south rather than improving. Stick with MRF Zapper FY1 90/80/17 you won't be dissappointed with the improvement in grip a that fresh rubber can provide. Cheers!



I have a query with regards to the idle adjustment screw on post 2014 models (with 02 sensor)

I know the older gen V1 and pre-2014 V2 (with three phase RR unit) had this screw to set AFR and idle RPM. But is it also present on the newer models of R15 V2 and S ??

If my knowledge serves me right an 02 sensor helps adjust AFR automatically by sending data to the ecu and making changes on the fly. So they should have got rid of the manual adjustments screw. Would highly appreciate your feedback on this.
Thanks.

Ride Safe!

On the fly afr adjustment?? Nope... FYI most of the bikes we get have a closed loop system that's only closed loop at idling. It senses parameters and estimates a range of weather conditions and then goes back to open loop mode by referring to pre loaded maps for the specific weather or estimated riding pattern.
The algorithms inside the ECU's are simple tables not some AI or machine learning algorithms which will adapt on the go.

I think there is some misunderstanding here in the above statement. So I will try to be more specific.

Let us take a brief description of : True closed loop & Open Loop FI

Open Loop
Open loop simply means there is no feedback of the result to the ECU. In our case, it means there is no sensing or measuring of the exhaust gas to see how the bike is running. The fuel injected is determined by the RPM and throttle position, derived from fuel injector pulse width numbers stored in the fuel maps. This was the case of earlier models of the 15.

Closed Loop
Closed loop means there is feedback of the result to the ECU. In our case, it means there is sensing or measuring of the exhaust gas to see how the bike is running. This sensing is done by a probe which generates a voltage based on the gas around it.

The main reason for running engines closed loop is for the efficient operation and compliance with emission norms. Also since the R15 has a narrow band lambda sensor as opposed to wide band sensors on bikes like the Yamaha MT-09. There is a time delay needed to get the air/fuel ratio cycling around stoichiometric, an accelerating engine can’t be effectively controlled in this way using Narrow Band sensors. This is why most Closed Loop systems operate only when the throttle opening is constant and the rate of RPM change is very low.

What does all this mean for the R15?

All of the above practical restrictions mean that the Closed Loop systems on the R15 usually operate at low throttle openings (below 20%) and below 50 to 60% of max RPM. Above those throttle and RPM points the system goes back to Open Loop operation, running off the fuel maps stored in the ECU.

Adaption (or self tuning) on Closed Loop Fuel Injection


The Closed Loop system is not only used for instantaneous mixture adjustment at constant throttle /RPM conditions. The changes the ECU makes to the injector pulse width to reach the cycling mixture as compared to the map pulse width is stored in what is commonly called an ‘Adaption’ table. This table is then used to trim the map value in future. Instead of having to work its way to the cycling mixture point in steps of incremental pulse width change, the ECU will start where it ended last time. The constantly updated adaption table is the self tuning facility talked about with Closed Loop systems, but it is often misunderstood.

As far as I understand it, the self tuning will only occur in a very limited band of engine operation, so it only happens at cruise, overrun and idle. And the self tuning system aims for a Lambda of 1, as this is the only thing the system can measure – rich or lean, not degrees of – with a Narrow Band Lambda sensor.

Hope this clarifies what I meant!


Source: http://www.bikeboy.org/open_closed_loop_efi.html

Best!

We can even drag a mt 09 owner here for further clarifications @chiku181. Please help [emoji23][emoji23]

Nevermind, No offence to be taken.

But I don't get how posting screenshots is any different than quoting an excerpt from a webpage (Might end up utilizing less server space even). Different folks, Different preferences I suppose.

I am also not seeking validation from any MT-09 owners here if you see what I mean. However any knowledge from senior members is always welcome!

Anyways I get what you and I are saying is partly similar. So I will redact my post to only include the statement which I think is contradictory.

Quite the discussion we had on FI though. Thoroughly enjoyed it!
Good Day!

[MENTION=78129]Maverick_BOSS[/MENTION]
Hey man, Good time to change the tyres now that monsoon is mostly been dealt with!

We have shed some light on this topic as it was raised by another fellow rider [MENTION=62910]aditya_YZF-R15[/MENTION] in the previous week. If you may scroll just a few pages back (Page 1282) on this thread. Refer to my post #12818 . Hope the info could be helpful.

But to sum it up. Try not to upsize/downsize the Front wheel. There are more chances of handling going south rather than improving. Stick with MRF Zapper FY1 90/80/17 you won't be dissappointed with the improvement in grip a that fresh rubber can provide. Cheers!



I have a query with regards to the idle adjustment screw on post 2014 models (with 02 sensor)

I know the older gen V1 and pre-2014 V2 (with three phase RR unit) had this screw to set AFR and idle RPM. But is it also present on the newer models of R15 V2 and S ??

If my knowledge serves me right an 02 sensor helps adjust AFR automatically by sending data to the ecu and making changes on the fly. So they should have got rid of the manual adjustments screw. Would highly appreciate your feedback on this.
Thanks.

Ride Safe!