K&N Air Filter and Snorkel Removal
 

Fitted my K&N air filter today, and while I was at it I sliced off the snorkel from the airbox lid. The difference is quite dramatic, in throttle response and flexibility especially. The pipes I have fitted probably help too (akrapovic's), but letting the engine breathe seems to have paid off. Ideally a PCIII would be next on my shopping list, but I don't think they're available yet. For now though, I'm well pleased!! :toothy5:

Thanks for the feed back.

Snorkel removal - Jetting
 

Hi!

Did you adjust the "jetting"?
I haven�t found any CO-setting on the Z.... adjust TPS? Resistor in the temp sensor line? It�s not good if the motor runs too lean.. //MC

Wow Tenere Doug, thanks for doing this and giving us feedback on the mod. I would be very interested in how the fuel consumption changes.

Call me completely untechnical and my physics didn't score very well in high school. I remember one said that if I have such K&N airfilter or any mods that "improves" the airflow, therefore, the fuel consumption would increase, 'more air burns more fuel', that's the logic. I thought about it a lot, and came to speculate that first we need oxygen, spark, and combustible materials to make a fire. If the spark is constant, then the amount of oxygen and combustible materials needed should be the same, so if more oxygen, less combustible materials needed, and vice versa. So wouldn't more airflow actually decrease the amount of required combustible materials which are gasoline in our cases here, assuming we hold the size of the fire or in our cases the power from the engine constant? Why I hold the power from the engine constant, because the fuel injection senses how much fuel the engine needs in order to keep the idling speed at 1500rpm on one hand, and the presumably optimal amount of fuel depending on the throttle position on the other. The fact is I have tried both the stock and K&N filter, and I have found the stock filter actually eats more gas than the K&N filter, but I just couldn't quite get my head around it. On power commander, am I correct that its main function is to manage the smoothness of power delivery but not so much on increasing power at any rpm?

Please keep us posted on how your gas consumption goes. Much appreciated.

I was thinking about the air filter set up on the Ten last night after adjusting the chain. The plastic side panel I can't see being hideously expensive, and the DNA stage 2 filters for the X and R's is basically a sidepanel with a filter in to allow more air in, so it wouldn't be too hard to make a sidepanel with some filter in to give more air surely?
Now the problem comes with setting the fuelling as I don't think the XT ECU's are reprogrammable like the SAGEM ones on my old Caponord, KTM's etc. This is where the PCIII comes in, as it sits between the ECU and the injectors and changes the signal to the injectors. Only changes the fuelling, not the ignition sadly.
Are there K&N or DNA filters available for the Tens?

yup,

http://cgi.ebay.co.uk/YAMAHA-XT660Z-TENERE-660-2008-K-N-Air-Filter_W0QQitemZ190288095423QQcmdZViewItemQQptZUK_ Motorcycle_Parts?hash=item190288095423&_trksid=p32 86.c0.m14&_trkparms=66%3A2|65%3A1|39%3A1|240%3A131 8

http://www.dnafilters.com/filterdeta...p?filterid=416

Yes, I have a DNA and Tenere Doug has a K&N. My DNA is no different from the stock, except that the thin alu surface around clearly allows much more air through than the stock. Mind you the Tenere's airfliter is located under the seat without any access from the side panels. One must lift off the seat in order to get to the airfilter. I am sure you know that, but I just want to clarify that we are on the same page.

Cheers guys, I did my usual and asked a Q without having a look first.
Josephau, yup I know how to access the filter thanks. I had a good look when I was draining the breather tube, hence thinking about the sidepanel filter.

edit to add- the calsport vendor in peatbog's link here is cheaper on ebay than in their shop. Though in their shop they have remus pipes for the Ten...including a de-cat y-piece.

Additional edit to add...bought one ;)

Oooo they do K&N oil filter for the Ten too..... and hardly expensive either

http://cgi.ebay.co.uk/K-N-Oil-Filter...742.m153.l1262

I guess it depends on where you ride, but doing this would lower your wading depth, and I think I'd be concerned with water ingress in heavy rain, it does stream acrosss the side panel - when it's biblical, like it usually is up here!

I did it to my TTR, gave loads more response, but I lost too much depth in water, so I replaced it with the stock one.

Agreed, I've run pod filters on bikes in the past and had the joys of rain water entering the system. I had in mind a louvered cover of some sort to help prevent water ingress, though not sure which way you'd fit it for best results!

So the K&N arrived today, nice fast service can't fault it.
I popped the seat off and took the old filter out, stuck the new one in and had a look at the snorkel set up. A testing twist revealed the snorkel could be removed from the retaining plate. So removed it was-

http://i97.photobucket.com/albums/l2...s/DSC00306.jpg

Bolting the plate back on revealed the K&N was loose in the airbox even with the plate on. This was no good and I didn't want to cut the snorkel about "just in case" ;) so after some shed searching I found some old fuel line and vacuum hose.
These were formed into doughnut shapes and a bit of insulation tape applied to ensure things stayed as they were-

http://i97.photobucket.com/albums/l2...s/DSC00307.jpg

I dropped the filter back in and placed the doughnut over the top then sat the plate in place before tightening everything back up-

http://i97.photobucket.com/albums/l2...s/DSC00308.jpg

Job done, without damaging anything and without spending 46Euros on an OTR plate :)

Good bit of home made engineering.

I did have a rake about for something to susbstitute the rubber too, but in the end I just "Stanleyed" the snorkel off! At the end of the day, I just wanted peace of mind that it would seal, and stay put. If I ever sell it, I'll just get another snorkel, but that won't be happening any time soon..!

Wasn't meant as a dig Doug. To be honest I'm going to refit the snorkel as I'm worried about lean mixture. I'll wait to open it up again til I can modify the fuelling with a PCIII or similar. I've got plans in the wings to build a new exhaust so will be needing to adjust the mixture definitely then.

No worries Tom! Like you I'm waiting for Powercommander to sort out a PCIII for the Z, just to make sure it's running at it's best, but I've done a few miles now with the snorkel off, and it does feel better.

I'm also running a dna filter without the snorkel. It runs very smooth. But I don't know if the mixture is to lean. Maybe Kev knows? There is a sensor in the exhaust. If the motor is running to lean this should correct it?

It will only correct the fuel mixture when the O2 sensor is in the closed loop, that is when you are mostly on the cruise & at lower RPM. Other then that it will run a leaner A/F ratio.

The XTZ's A/F ratio is still unknown as I do not know of anyone running one on a Dyno to see what Yamaha have done with the fuelling.

Hi Josephau - I can see your thinking, but that's not quite right... the optimum burn ratio for a petrol engine is about 15:1 I believe, so if you have more air then you are going to need more petrol...

However, as the engine is arguably now working more efficently, you might find you use less throttle for a given engine speed/road speed, and therefore save fuel? Certainly the bike does feel a bit 'corked' as standard, so you tend to wind the throttle open harder than you might if it were breathing more freely?

I too would be interested to see how significant the change in fuel consumption is with the snorkle removed...

xxx

Hi Tom - I'm sure you've realised, but you are aware the side panel is on the post filter side? - ie. the original filter wouldn't be doing anything if you cut the side panel open, as the whole airbox is after the stock filter, so you'd have to put a filter in the side panel and seal it well (and may as well do away with the original)...

btw. the right hand airbox side panel is around a tenner... don't ask me how I know this x

xxx

Hey JMo, cheers for the price guide, yeah that was kinda the plan, not sure it'll happen but I like to muse on these things :)

Thanx Kev,

I'll have to put it on the dyno then. For now I'm running with the standard paper filter again.

Yes indeedy, a good mod. Copied it myself today and had a good ride around, mixing urban commuting with motorway blast. Did a plug chop and the condition looked good, so I dont think that the snorkel removal has had much effect on the mixture, but now the bike is breathing colder air rather than the hot jet it was getting down the snorkel. I'll keep an eye on the condition over the next few days and report back to the forum.
Wimpster

Done about 500 mixed miles since I carried out the snorkel removal, and all seems fine. Mixture unchanged, and seems a bit crisper off the throttle low down. Also, you get a nice induction roar as a bonus!!!! So , it would appear to be happy days all round.!!!

Cold air would be more dense than the heated air, so there would be more in the cylinder, thats why an intercooler is fitted to a turbo vehicle to cool the air charge.

Hi Kev

I came across the below link featuring a K&N filter which they state fits the Tenere - I havn't seen it on any of the threads here so would appreciate your thoughts....

http://www.intobikes.co.uk/products/...latest&sd=DESC

I hope that is just a generic photo, as it certainly isn't the drum type of the new Tenere - although they also have the name of the bike wrong (it is a XT660Z Tenere, not an XTZ - that's the old 90's version) - so maybe they have confused and that is a filter for the earlier bike?

xxx

Hi, yes the picture is a generic one....I have this fitted to my 08 tenere, the part number gives a clue to bike fitment.... YA6608 ( Yamaha 660 2008)

Hi, your local Yamaha dealer should have the diagnostic tool, which includes a Co adjustment, it is the same tool used for Raptor 700s. I used this tool on our demo bike with K&N and Akro pipes, and got quite good results!
.

O2 sensor function
 

[quote=Kev;85073]It will only correct the fuel mixture when the O2 sensor is in the closed loop, that is when you are mostly on the cruise & at lower RPM. Other then that it will run a leaner A/F ratio.

Hi Kev,
1/ I would like to ask what do you mean by "closed loop" function of O2 sensor. I assumed, that O2 sensor (lambda) is functional in ALL engine loads and speeds to correct the right A/F ratio - let say "feedback" from exhaust gasess O2 volume analysis - back to ECU, to correct the amount of injected fuel. Could you advise the limiting of O2 sensor function depending on RPM, etc.?
2/ I suppose that O2 sensor is able to correct slightly changed A/F ratio (for example by snorkel removal), but the main issue for me is unknown "range", in which the O2 sensor is possible right correct the A/F ratio (in case of new cans, etc.)
3/ What wil happen with the catalysator in case, that we will change the A/F ratio due to new cans, DNA, etc. - for example by tricking temperature senzor to run more rich fuel?

Thanks, Jiri

[quote=George;111626][quote=Kev;85073]It will only correct the fuel mixture when the O2 sensor is in the closed loop, that is when you are mostly on the cruise & at lower RPM. Other then that it will run a leaner A/F ratio.

Hi Kev,
1/ I would like to ask what do you mean by "closed loop" function of O2 sensor. I assumed, that O2 sensor (lambda) is functional in ALL engine loads and speeds to correct the right A/F ratio - let say "feedback" from exhaust gasess O2 volume analysis - back to ECU, to correct the amount of injected fuel. Yes you are quite correct, the O2 sensor sends a 0 to 1 volt signal all the time the bike is running. The ECU only looks for the closed loop voltage signal only at certain times predetermined by these conditions, when the bike is at operation temperature , when you are cruising at constant or small throttle openings & below 4000 RPM. Could you advise the limiting of O2 sensor function depending on RPM, etc.?

2/ I suppose that O2 sensor is able to correct slightly changed A/F ratio (for example by snorkel removal), The O2 sensor is not a tunning device, it will lean out or richen up the fuel mixture trying to keep the A/F ratio as close to lambda control when in the closed loop.but the main issue for me is unknown "range", in which the O2 sensor is possible right correct the A/F ratio (in case of new cans, etc.) Answered above.

3/ What wil happen with the catalysator in case, that we will change the A/F ratio due to new cans, DNA, etc. - for example by tricking temperature senzor to run more rich fuel? In the open loop the bike will run lean with these mods, so a fuelling device is needed to correct the A/F ratio, we have had no reported problems over the past 5 years with any damaged Cat using these mods.

Thanks, Jiri

Thanks for all explanation, Kev!
I have to confirm, that O2 sensor is limited in function. A month ago, I replaced old coolant temperature sensor in my car (equipped with O2 sensor). I measured both old and new temperature sensors (thermistors) by different temperatures and the result was, that the old sensor gave information, that coolant temperature is much colder, then in reality. After replacing of the temperature sensor, I felt a huge difference in performance – especially by cold engine (= limited O2 function), when car was lazy and hesitated with old sensor due to rich fuelling. But by hot engine, there is a difference too, so I suppose, that O2 sensor was not able to correct the right A/F with the old temperature sensor.
I had 2004 XT660R with surging and jerking, replace of ECU (type 2005) helped a lot, but some surging remained. Now I have 2008 XT660Z and I must say, that the performance is quite different – smooth, no surging (only slight “jerk” by throttle opening in low rpm, typical for injected engines) and you can go in lower rpm with XTZ. But, I was surprised, when I changed my new XTZ with my old XTR on one trip with my friend, who bought my old XTR. The engine performance of XTR was really much more better in low rpm (we had the same feeling with my friend) and I think, that in high rpm, the XTR was slightly better too :-( The XTR had 22000km and XTZ had 2000km on clock. I think, that the new Euro standards are the reason. XTR had lower environmental standards (uncontrolled cat), so the engine was not as limited...
Thanks Kev!
Jiri