Bacardi, I do not have a problem, the bike runs really well.
You are correct about the spark plug ID, I noticed it when I looked at it yesterday.
As it has only done 8000km according to the service specifications it would not need changing until 20000km.
But I bought the correct one a few weeks back as a spare anyway.

I will take some pictures to send you of the SS header pipe tomorrow. My camera is not so good but I will try.

Jens, thanks for the detailed reply and instructions on how to read the spark plug.
As I am getting it put on the dyno tomorrow I can check the air/fuel ratio from there (hopefully the read out will be like your format).
Then I will be fitting the new header and filter both of which I have so this may lean it out anyway. The silencer should be here in a few days.

Then dyno again.

Did you ever get a second dyno after your modifications?

me? Yeah got it on a dyno after the mods, but with poor jetting, way lean in the bottom, and very rich int he top. Guess how i leaned the whole "read the spark plug" thing =)

It showed same HP output, the curve broke when the mixture got too rich. Im not after top effect, but i know 40 horses on the wheel can be achieved with filter, header, exhaust and rejet/dyno jetkit. (as in, without digging into the engine)

I would use the correct spark plug, and use the wrong one for a spare. Actually i would through the wroong one out, and use the couple of bucks for a correct one, for a spare :)

IM really looking forward to your're results, hope you share them with us asap :)

:offtopic:

Guestimating, how many HP do you guys think one should obtain on the back wheel with stickys , raptor 660 carb with dyno jetkit, new K&N filters, Devil bigbore SS headers, 06 WR450 rear or Jardine universal muffler?

Richard any ideas?

Vando :Beach:

Who? Me? No idea, I'm afraid. I haven't done any of this performance mod stuff with mine. I'm just grateful if it starts and keeps going :)

I am pleased and lucky that my XT runs nice and smoothe so I certainly don't want to mess too much and ruin what I have.
The SS headers, pipercross filter and marving silencer will probably do me.
I don't think the marving silencer is particularly performance enhancing but it looks better and certainly weighs a lot less.

Just for fun I weighed the stock header and silencer, 7KG 15 1/2 lbs.

I will be happy with a 3-4BHP (10%) increase at the wheel and don't really want to get into rejetting.

Bacardi I took a couple of pics of the devil header to send you.

Jens I have the print outs from today, very interesting results.

Apparently there are different ways to test, mine was done at "wheel SAE", not sure about yours so hope we can still compare notes.

Unfortunately I do not have a scanner so I used my average digital camera.
Hope it will be viewable other wise I will have to think of another way to post them.

Dyno was done with stock bike.
The picture is of Torque and BHP.
The website wont let me post the print out for throttle response, speed and BHP because I have exceeded my quota whatever that means.

10% increase sounds about right for a freeflow exhaust and air filter with corrective jetting :thumbup1: so should be nigh on 40bhp at the rear wheel :mchappy:

Cant see it real good, how many hp ont he wheel? Mine was 34,6 with oepend up stock exhasut and pipercross filter, uh and the airboxcover renoved. That was meassured on a road tire.

had a closer look and it looks like its making about 33bhp in standard trim, the new headers will be the extra advantage so i'd say in total if the jetting is right he might just get it upto 38bhp :cool4:

32.9 hp @ 5812 rpm Torque 43.6 m.N 3737 rpm
33.2 hp @ 5734 rpm Torque 44.6 m.N 3758 rpm
33.4 hp @ 5765 rpm Torque 44.7 m.N 3904 rpm

With a Kingstire knobbly, there is a pic of it in another thread.
I am going to change them to Avon Distanzias.

Got home after dyno and fitted the ss headers, took for a 5 mile ride. Came back and fitted the air filter. Waiting for the silencer and iridium plug then I can take it back for another dyno.

I'll be happy with 37BHP at the wheel.

Don't think I want to open up the air box or rejet unless I have to.
The guy said it is running really well and the throttle response was smoothe all the way 167KPH.

He also printed out the "Crankshaft DIN"
37.2 hp @ 5812 rpm so it lost 11.75% from crank to wheel.
37.4 hp @ 5734 rpm so it lost 11% from crank to wheel.
37.6 hp @ 5765 rpm sp it lost 11% from crank to wheel.

10-15% is what I had heard would be lost from crank to wheel so this fits but it is well short of the 44-45 BHP Yamaha give it in the specifications.

yam quoted 43bhp on the old literature plus your bike has got 7 years on it from new so it will have lost some of its power anyway also corrected bhp is still not an exact figure there are factors like chain weight wear and length on top of tyre friction losses so dont worry too much about any figures quoted on your dyno runs as long as it goes up after the mods and it rides well enjoy the the beastie :thumbup1:

just looked at the dyno for my rf900 it says 128.4bhp rear wheel din so corrected horsepower at 11% would put a 1994 rf900 at nigh on 140bhp which is pretty impresive even by todays standards

GSXR X40F0X on a XT600Z 3AJ
 

Id say they was tight enough already, just got mine last week & the fit is pretty tight (push fit).
I thought it came with sealer then worked out they had sent me a licorice wheel (looks like exhaust sealant). :blushing:

http://www.lightwire.net.au/tenere/s...%20headers.jpg

Im going to be using a Gixxer 1000 titanium can on mine (2kg),
flange is on order & need to have a midpipe made at 45mm not the 42mm it drops to on the left of the pic.
This is a mod done on the DR650`s by MX-Rob i had a spare can so i thought try it on the XT.

http://www.lightwire.net.au/tenere/X...%203AJ%20a.JPG

You can see more here.

Mezo.

Yes wolfzero a 10% gain in bhp from a couple of simple mods can't be bad.

As I prefer twisty country lanes to straight roads or motorway riding I would like to lose some top end speed and gain some acceleration so was thinking of changing my 15 tooth front sprocket to a 13 tooth. I think I read of someone using a 14 and it was not enough difference.

Mezo, always glad to see pics of other XT's.
Lol at the liquorice, when I first saw it I thought it was sealant too.
I had some sealant in the garage but fitted the headers yesterday and it is not leaking at all so did not use it.
I found the flanges were bending as I tightened the nuts to the head.
Did you get the 2 plastic spring covers? Not necessary in my opinon as they are well clear of the pipes.

03XT600E Don't go smaller on the front sprocket, go BIGGER on the back!
Yes you might need a longer chain.. but what you'll save in terms of engine life will is alot more than going cheap on the front sprocket..
but hey, it's up to you....

I'm thinking of going 15/47 on my 600e and get a 16 front sprocket just to try it out with 16/45


Vando :cool4:

I'd go for a larger rear too. If you go too small on the front, you may have several negative issues:
The chain will be nearer the swingarm & may rub.
The tighter the chain has to turn, the more wear & more power loss.
Larger sprox wear better as the load is spread over more area.

Just me 2p worth :mchappy:

Thanks for the information regarding sprockets, I had not considered the negative effects.

I am prepared to lose 10-15mph off the top end to get some more poke.
As I understand it -1 tooth on the front is = to +3 teeth on the rear (please correct me if I am wrong).

So would going from 15/45 to 14/47 be the thing to do or may that still cause problems by reducing the front?

If so I guess 15/47 will have to do.