XT600E 2002 Performance Mods ?

[caspaflip]

Hi Guys ,

Im a newbie to this forum im from Australia , i have just bought a 2002 Yamaha XT600E which has 90,000 klm and a one owner bike. I have fitted one of our Remus Freeride slip on muffler & lifted the airbox lid.

I just bought the bike and after a check over is due for a cam chain and probably a complete top end rebuild considering its never had a rebuild.

Now that im going to do a top end rebuild has anyone on the forum fitted a big bore kit or done some cylinder head mods like a port & polish to get more power from there XT and if so what sort of power increases have they got ?

Any help would be great.

[carlhenrik_80]

Hello there!

When your bike has gone that far, and you want to keep the costs low, and still are going to rebuild the top end, dont forget to re-grind the valves.
Be shure they are tight, specially the exhaust valves, but check all 4.

I have done it with my XT600-2KF, 1989, who has done about 65000Km.
Also rebored cylinder, new piston with new rings, and it became a new bike!!

Another thing: If its beginning to sound like a chainsaw in 5th and 4th gear, then maybe you should consider a gearbox service...

Must tell I have tried several years ago to fit a Wiseco High-compression piston, heard it could do about 7hp power increase together with a slip-on, depending on tuned carburettors, but I changed back to original piston to get longer service intervals AND less vibrations... But the slip-on remains on the bike, and I think it does about 10% power increase from the original 45hp on my bike.
All parts fitted who is not original spareparts shortens the service intervals very much. Specially the piston. And the bearings, but thats another thread..
Long intervals could be one of the reasons we have this bike...

God Luck!

/ Henrik

[caspaflip]

Hi Henrik,

Thanks for your advise , much appeciated . If anyone else has done any performance modification to there XT600E it would great to hear from your experiences !!!

Cheers
Mark.

[Jens Eskildsen]

I've done an attempt.

Kedo ovesize stainless steel header
Laser produro exhasut
Opened up the airbox
Pipercross foamfilter

It didnt do a lot to the horses, my guess is max 5hp. Most of it is looks and sound.

But it did get the low and midrange going stronger. But nothing that will make you wheelie in 2nd without the clutch and stuff like that

I have still not compared it to another xt, I hope to do it this spring.

My bike is a 2003, and it has done 72.000km.

Heres a recent pic:

[Pigford]

Jens, what mods did you do to the carbs ???????

[Jens Eskildsen]

Now its #50 idle jet (46 stock, i think a 48 could do the trick to)

132/120 jets (130/120 stock, i bet stock would be just fine to)

Raised both needles one notch.

Heres the dynorun when stock (with opened airbox, foamfilter and opened up stock exhast) http://peecee.dk/uploads/022010/xt600rulletest.jpg

As you can see, the powercurve is pretty steady, and so is the air/fule mixture. However, the air/fuel mixture is around 12-12,5......You could easely get away with 13, I actually think its normal to be around 13,5.

If I could turn back time, I would have choosen +1 on idle jet, and then test from there.

[-ralph-]

Jan's, how come your power curve only shows about 33bhp, when it's supposed (!) to be a 43 bhp bike, and you added 5 bhp in mods?

Is 43bhp a complete fabrication on the part of Yamaha?

EDIT: Ignore me, just looked again and realised it's power at the back wheel, not at the crank.

[Jens Eskildsen]

34,6 at the wheel, as almost stock bike. This was before the header, exhaust and rejet.

I've seen specs from 40-48 crank horses. I really dont know for sure what they really are. But 40-45 doesn't seem totally unresonable.

ALso, tires has a lot to say when you dyno. Knobbbie tires suck som horses, cause street tires has much better grip, and not so much resistance.

Do te mods to make the bike look cool, and not to gain horses. Then you can be delightly surprised if you unleash a horse or two.

The xt will alwasy be a xt, heavy and underpowered, but damn its a nice and "bulletproof" engine.

[Pigford]

Cheers Jens

I believe the old XT motors like running a bit rich to aid cooling (safer than too lean).

The dyno run shows very warm conditions (28 degs) and low atmospheric pressure (below 1000) so it'll lean out a bit when its not summer.