Air Box
 

I have a 2009 xtx which has a number of holes drilled in each side of the air box.

Yes I know why someone has done this before you stop reading my post !!!

3 holes pre-filter on the nearside of the bike with some metal gauze taped over the holes (presumably to keep out some of the crap?) and 3 holes on the offside (normal filter entry area) with a plastic plate riveted over 2 of the more exposed holes, leaving 1 open hole post filter.

The bike does have a K&N filter fitted but as far as I�m aware no other mods have been carried out.

Having read a vast number of posts about air box drilling and the �Kev� mod etc etc, I�m confused as to whether this will make any difference or will adversely affect the bike, in fact make the bike run slightly lean as there�s obviously more air to fuel than was originally intended. Will it cause more harm than good ???

I�m currently verging on the side of chucking this air box away and installing a standard box with no holes unless someone can give me a good reason why I should keep the air box as it is.

I�m not planning to carry out any other mod�s or fit a power commander etc. as I don�t believe for the vast amount of money spent these in reality make that much of a difference, all be it that the placebo effect must kick in with many people after having spent hours fettling and ������s on various gismo�s.

Any advice and reasoning would be appreciated.

Every mod I have done on this forum has been dyno proven with before & after runs no placebo guessing here, one can gain up to 8 extra HP from air box mods proven fact. Modifying is a personal thing so I am not going to try & convince you to do anything, all I have done on the forum & many others is provide the facts.

Your bike will run fine with the K&N filter with the extra holes drilled, if you want the full effects of the extra air intake you need to fit a fueling mod, more air more fuel more HP & Torque, we have had thousands of XT660 forum members running the same setup as your bike with no problem over the past 5 years. We have guys running stage 2 filters with no fuel mods & have never seen any engine damage in the long term. But I do recommend fitting a fuel mod when opening up the air box.

If you want a completely standard bike buy some rubber grommets from your local hardware & plug the holes up, remove the K&N filter & buy a paper Yamaha standard filter, it is a major job to swap over a air box about 2.5 hours worth of work.

Have a read here to see proven Dyno HP gains.

http://www.youtube.com/embed/Te0V71sGoxA

This is were the net falls down a bit as it never comes across right,I run 3 other bikes apart from XT that have things from BST's to PC's!!,the XT was staying stock,although it came with Akra's on.

I bought a DNA stage 2 filter,then a stage 1,then took the snorkel off,after each mod rode the bike it ran pretty dam well but couldn't bothered with a PC,after much umming and rrring bought Kev's fuel mod,which I have to confess wasn't expecting too much(sorry Kev!!)and it was the icing on the cake,just haven't got round to drilling the holes in the box.

Now this is were it gets complicated for me,I've been tempted to buy a KTM 690 SMC,I haven't ridden one and I've seen a posting on the KTM website saying that an XT with the above mods isn't far short and the way mine goes now it's not a clear cut decision.

So after my ramble,leave the holes buy a DNA stage 2 filter(it's a rip off at that price but it does work) and K+N will do for the 1 and buy Kev's fuel mod.

Confession time again,you only have to alter it a nats and it makes quite a difference,which also suprised me,oh and the other thing!! buying from Australia!!! came within days,this should have been headed confessions of a non beleaver,I normally go the big bucks route!!.

+1

The "Kev" fuel mod is a cheap, easy to fit and a very worthwhile improvement. I'd suggest it is at least worth thinking about if your airbox is already drilled and fitted with a K&N.

Apologies if you feel offended Kev, I’ve had other bikes and carried out various mod’s and I’m sure if the bike was put on a dyno it would possibly show some small improvements, when referring to the placebo effect I simply mean that when someone spends a lot of time or money you feel that the bike should be better than before, even if it’s very difficult to actually tell the difference when riding.

I installed an Ivan’s jet kit into my Fazer 1000 some time ago after having read great things, and to be honest I couldn’t really notice any difference, but put the bike on a dyno and I expect it would show some changes, and plenty of people who had carried out this mod thought the bike had improved, I’m just not convinced that certain modifications can really be noticed.

You appear to be somewhat of an XT660 Guru and from the extensive list of alterations you’ve carried out I guess you have proven that the bike can be made slightly better, however as with all things this does come at a cost, you certainly have many followers and from the responses people are pleased with what they’ve achieved.

So I now want to read more details about the fuelling mod but I can’t because “Access is Denied”, I presume this is because I’m not a member of the “Private Forum” ???

I appreciate everyone’s feedback and feel a little more secure in the knowledge that the holes will not affect the engine, I guess one of my main concerns was the home DIY person who decided to bang holes in all over the airbox, didn’t take any of the swarf or the plastic washers out that were created by drilling.

I have the airbox on the bench so it can be cleaned out properly, I’m just not sure which way to go, patch up the holes which won’t be easy as they don’t appear to have been drilled with anything other than a wonky hole saw, or leave them open knowing the bike should run okay !!!

I'm not a private member either,but I remember reading on here without any hassle,I wouldn't have ordered it otherwise.

I have to say I hardly consider mine to be modded,2 akra's already on,2 filters,and gizmo to ajust the fuelling and it's a world away from how it was,and use the bike in preference to these,loads more fun.

http://i64.photobucket.com/albums/h1...ans2011056.jpg
http://i64.photobucket.com/albums/h1...0102011087.jpg
http://i64.photobucket.com/albums/h1...res2008029.jpg

[QUOTE=sezian;167412] Apologies if you feel offended Kev, I�ve had other bikes and carried out various mod�s and I�m sure if the bike was put on a dyno it would possibly show some small improvements, when referring to the placebo effect I simply mean that when someone spends a lot of time or money you feel that the bike should be better than before, even if it�s very difficult to actually tell the difference when riding.

If you have a fueling mod + DNA Stage 2, you have to be pretty daft not to notice the difference, it's actually very noticeable and when it comes to price of motorcycle mods, that's probably one of the best bang for buck you can find in any mods on any bike. If you never open up the throttle all the way, then you might not notice though. I would eve guess that most people here have done this mod to fix the annoying surging that the older models have, this goes a long way in helping with that too.

I'm a bit of an paranoid and I use my DNA Stage 2 only during the summer and autumn, not during the dusty spring season, but many people use the stage 2 around the year and are very happy with that solution. However changing the filter to the air box cover takes literally about a minute, so it's not a big deal, I have maps for both in my PC, and also used to have settings in my Kev mod for both options, so fueling was also under control, however it seems that with Stage 2 I end up driving more aggressively and therefore use about 0,5-1 l/100km more fuel.

No offence taken at all, just want to provide the facts for you, the Dyno does not lie when before & after tests are done.

The Kev Mod info you are after, the fuel mod can be used on all models & all year XT660's.


To download any of these links below copy & paste the links to a URL & click DOWNLOAD NOW click SLOW DOWNLOAD wait for the counter to count down, then click DOWNLOAD file now save the files to a folder on your desktop.


http://www.4shared.com/document/cbviy3uX/The_Kev_Fuel_Mod_2004_to_2010_.html

Kev, many thanks for the download an explanation of what can be achieved. I will consider the mod when I get the bike on the road. As yet I�ve not ridden it which may sound strange but I bought it as an insurance right off, mainly cosmetic damage, plus new radiator needed, clutch cover cracked and I suspect one of the forks may be a little bent.

Perhaps you could clear up another important point, are the airbox mod�s and fuel mod only noticeable at the top end of the rev range / full power ??? Or does it improve drivability throughout the entire rev range ???

As mentioned I�ve as yet not ridden the bike so don�t know if it suffers from surging or not, it�s a 2009 model and from what I�ve read I believe the later bikes had this cured? I can remember a BMW 1100 GS I had so definitely know what surging feels like, those bikes are awful for that !!!

You'll notice the difference from tickover,but you certainley will midrange when the motor starts to work the difference is remarkable,to the point I've never really felt the rest of the bike needing sorting as it was able to handle what hp the motor put out but since the mods I've had thoughts that the rolling chasis is struggling.

A fueling device offers an increase in A/F ratio across the whole rev range & does make the bike smoother through the whole rev range.

Not all XT660's are equal we have 5 different levels of firmware, all with different tune states. You can read about them here.

http://www.xt660.com/showthread.php?t=8546

As for your bike a 2009 model with O2 sensor the only way to get it to run smoothly low down or on the cruise is with a Power Commander + their O2 Emulator or my Fuel mod + my O2 Eliminator.

I no longer make my O2 eliminators as no one was buying them, so like some of the past XT660 mods I used to make I have stopped making the O2 Eliminators, I do have one left but it has been reserved until Sunday night 29/1 then it will up for sale again if not bought.

These XT660's do not like a A/F ratio of 14.7:1 where Yamaha have programed the closed loop A/F to. If you want a smooth XT660 ride with good fuel consumption you need the A/F ratio set to 13.6:1 in the open & closed loop. If you want to chase the best HP & Torque the A/F ratio needs to be set to 13.2:1, facts all Dyno proven.

An A/F ratio of 14.7:1 has nothing to do with a good running motor at all, it is set there purely for emission control & does not offer the best fuel consumption at that A/F ratio due to the fact you have reduced HP & Torque.

What I'd forgotten,want to know how well it runs??,never use first gear,it'll pull 2nd from the lights and still start to pick the front wheel up,do folks!! bikers in particulary get really upset?? oh yes!! with long legs from a standstill!!!