Have a read here first mate. http://www.xt660.com/showthread.php?t=630

mt03 injector
 

hello, this is my first post,thanks for a great forum.reading comments on mt03 injector,i have owned one of these from new(may 06)it now has 2500 mls on the clock.I took out the demonstator and it cut out with me twice,my new bike did the same at crossings and road ends so i had a word with the mechanic and he richened the mixture a tad,it is not possible to do this on the speedo on the mt03 it has to be plugged into a hand held computer.this did help but the bike does not fuel properly when in town,it seems to surge slightly when on a small throttle.it looks like yamaha still havnt got it right, I will do the mod on the engine breather as this has got to help. many thanks again for an excellent forum....Eck....

Hello Eck,. welcome to our forum

Try that, see if it works otherwise see if Kev can sort you out with one of his mods, what the 'eck :D its got to be worth a try.
:wav: :wav:

Engine Noise - valve like
 

My XT660R makes sometimes a noise at start that comes from inside the engine, feels like the noise of a valve hitting something, it makes it only once and then stops, some times does it when in iddle position and suddenly give it some acceleration. the noise is la la clank, feel like fuel was cut for a milisecond.

Any ideas

Not being very mechanically astute, I think what you describe is called pinking, resulting from low octane fuelling or being too lean.

Update, test results
 

Saturday I had some mates around to my house to run their XTX's on the Dyno. The results after 19 runs, good to know mates that own their own Dyno Jet Dyno.

Kev's bike 2004.

Kev Fuel & airbox Mod, DNA stage 1 & 2 & a set of Carbon Cans. Snorkel removed

45 HP STD to 50.4 HP = 5.4HP gain 12% over STD.

43.2 to 47.5 ft-lbs of torque = 4.3 ft-lbs gain 10.5% over STD

Kens Bike brand new bike 2006, 62kms on the clock. Being brand new I would expect 1 to 1.5 HP more from the motor once run in.

Kev Fuel & Airbox mod & DNA stage 1 & 2 filters. Snorkel removed.

44.8HP to 48.1HP = 3.3HP gain 7.3% over STD

43.1 to 46.9 ft-lbs torque = 3.8 ft-lbs gain 9% over STD

Dan's race bike 2005. Total price of mods AUD$ 60.00

Kev's Fuel & Airbox mod, STD filter paper cut out to leave gauze only, three extra holes in side box cover. STD pipe mod, removed end plates on STD pipes, knocked a 20mm hole through the Cat & refitted the end plates.

45HP to 51.4HP = 6.4HP gain 14.2% over STD

43.0 to 48.1 ft-lbs of torque = 5.1 ft-lbs gain 12% over STD

45.0HP STD
47.1HP snorkel removed & STD pipe mod.
51.4HP Kev mod, filter mod, STD pipe mod.3 extra holes in side cover.

We are planing more dyno runs in 2 week time & will play with Dan's bike as he wants more power. I still think we can get more power from that airbox, this motor realy wants more air & fuel.

It's very hard to compare bike HP's on paper, done at different sea levels with different ambient temp & altitudes with correction factors. The only true way to know for sure if there is any gain is a before & after Dyno run.

Will keep you posted.
Kev

I want to move to Australia!!!, look at those lucky sods in their shorts and t-shirts and then look outside your London flat's window, do I make sense? :aska[1]:

More results
 

An update, I have put together the Kev mod results tested on the same bike. (Graphs 1 & 2)

1> Lower line, is the Standard 2006 XT660X, with no Mods.

2>Middle line, is the Kev Fuel & Airbox Mod

3>Top Line, is Kev Fuel & Airbox Mod + DNA stage 1 & 2 Filters

Next I tested Carbon Cans with baffles in & out. (Graph 3).

1> 53.1 HP Out. DB reading, bike stationary in neutral at 3000RPM, 1.5m distance from exhaust 102DB

2> 52.5 In. DB reading, bike stationary in neutral at 3000RPM, 1.5m distance from exhaust 94DB

Next test, TPS set at 19 & then set to 25. I have found if the TPS is set to 25 the bike will surge more then set to 19. (Graph 4)

1> Top line, Blue & Purple TPS set to 25

2> Bottom line, Green & Red, TPS set to 19

Lastly, a before & after for Dans bike. We started with 45HP on dans bike 2 weeks ago. .(Graph 5)

1> Red line, Kev Fuel & Airbox mod, Air filter mod, side Airbox Lid mod, Standard exhaust mod.

2> Blue line, Kev Fuel & Airbox mod, Air filter mod, side Airbox Lid mod, Carbon cans baffles out, TPS set to 25

So after my reply from CCC to not adjust my CO setting from 6 after fitting their pipes, what setting do I go too please, as on 14 it ran like a Kangaroo unless given a big handfull.
Note no other mods as yet, on there way, standard air filter dirty though!
From reading this section it looks like I need to go a lot higher even before modding the airbox and changing filters.

HELP PLEASE and I'll pay up to the supporters bit!

strat.

Pay first, then we will help you!!!!!!!!!!!!!!!!