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03XT600E 11 Jun 2010 15:16

Tune up
 
I am looking to increase performance mainly in lower end grunt and acceleration, so which piston and head should I be looking at?
I am not bothered about top end.

I see Kedo sell a 98mm 10:1 635cc or 101mm 10.75:1 675cc, both 141Euros.

I would take it to a specialist to do the work and maybe get them to gas flow the head and fit a new camshaft.

bacardi23 11 Jun 2010 15:30

Personally, I'd go with a "Wiseco" or "JE performance" piston a +1mm with 12.1 :1 compression and a stage-1 camshaft(cost around 220euros + shipping), opened up airbox with hi flow air filter, kedo downpipes, a good muffler, hi-speed inlet ports(reduce inlet ports at least 20%) and jetting everything accordingly!

That's just about the best performance gains you can get out of the XT's engine without sacrificing much reliability and not getting you broke!


Vando :cool4:

bacardi23 11 Jun 2010 15:42

If you want a little more poneys out of the engine you'll have to do some extra work and spend quite bigger amount of money...

A forged clutch basket with a good clutch disc kit with HD clutch prings which is lighter and gives better performance and cooling. (these baskets normally have alot more holes for the oil to go through!)
A lighter flywheel rotor.

Have you ever serviced the engine before? replaced piston or valves or clutch or whatever?

If you have, I'd recommend a complete engine flush and cleanup!
Why? because most of the performance lost in an engine is due to friction!
friction caused by using dirty tools, dirty hands, uncleaned parts, mixture of old oils etc etc etc....

Also, one of the parts you should have EXTREME CAREFULL when replacing parts is where the camshaft slides in the top of the cylinder head!
Any touching with tools there and it'll make scratches even blemishes are a problem for friction and dirty tools is def a no no!

Have fun! :cool4:

03XT600E 11 Jun 2010 17:00

Yes I have already got the devil big bore headers, silencer, piperx air filter, snorkel out, iridium plug.

So for low end grunt and acceleration you would suggest a piston +1mm with 12.1 :1 compression (rather than the 2 I mentioned?) and a stage-1 camshaft.

Would that be from Kedo? I got their new 2010/11 catalogue through this morning.

I have only ever changed the oil, oil filter, plug, air filter, never touched the piston, valves or clutch.

bacardi23 11 Jun 2010 19:27

Hi! well.. stage-1 camshaft supossebly offers better low/midrange...

For low end power I suggest you also change your sprocket combo!
I may offer to suggest 14/47 for more power and so you don't loose too much top speed as well...

As for the pistons.. I suggest you don't go directly to the 101mm upgrade...
Yes, it should give you some very nice power but I don't think the crankshaft would hold up too long with that PLUS, any cylinder damage and you'd have to either get a new cylinder sleeve or even a new cylinder!

I haven't seen the KEDO piston kits but I'd personally go with a Wiseco or a JE performance piston.... JE pistons are widely used on NASCAR cars so I believe they are of really good quality and very much comparable to Wiseco!


I do suggest you one little thing... a magnetic oil screw!
A Hi flow oil filter could also be a good thing...

Vando :cool4:

bacardi23 11 Jun 2010 19:29

check this link for the camshafts:


[url=http://www.je-kolben.de/index2.php?view=nocken&HID=28&lan=en]Gro

just delete the "[url=" and the "]Gro" parts..... HUBB IS GETTING CRAZY lol

03XT600E 11 Jun 2010 19:55

I originally changed the sprockets to 14/47 but then bought a blue annodised 54 tooth rear sprocket so have 15/54 and love it.
I spend all my time on twisty lanes so 60mph is plenty top end for me, I just love bottom end power.

I already installed a magnectic oil plug and hi flo filter.

Thanks for the link to the camshafts, however the page "Yamaha XT 600 built 1983-2004" wont load for me in English, It will load in German so have translated it.

How does this sound for me?

"Big bore - Stage 1 tuning kit The camshafts reprofiled and surface treatment. The camshaft sent must not be broken! Choice of Camshaft - Profile level 1 or 2! The cylinder is drilled at 97 mm, chamfered and honed. CP - Forged piston kit in a class of 97.00 mm, + 2 mm oversize, compression 10.5: 1 The pistons are supplied with matching piston rings, pins and clips The cylinder head is performance-revised. The valve seats are milled streamlined and performance-optimized channels. Including combustion chamber and glass bead channels. Also contains the Topend Seal for the model years 1988 to 1996. Please give us the Year."

Could you please tell me the difference between a stage 1 and 2 and race cam?

bacardi23 11 Jun 2010 20:15

Hi...go to: [url=http://www.je-kolben.de]Gro

Jens Eskildsen 11 Jun 2010 21:21

Kedo offers different cams, depending on if you want low, mid og high range performance.

When you do all this, remember this:

Its til a xt. Its still real heavy, designed in the 1980's with bad suspention and stuff like that. The reasonable thing would be to sell the bike, and buy another more suited for you're needs. Project bikes are fun, put awfully expensive.

You could gain a lot of "seat of the pants horsepower/torque" just by riding a bike with same performance, and 30kg lighter.

If yoiu do al this nice stuff to you're bike, remember the suspension.... The brakes arent all that bad imo. They're not exactly race ready, but adequate imo. :scooter:

03XT600E 11 Jun 2010 22:13

You are right Jens, it will always be an XT.

I was looking at XR650's which are abour 50lbs lighter I beleive but decided to stay with the XT and spend a few hundred euros to get that extra horsepower.

Yes the brakes are pretty good, actually the front brake is very good, I am upgrading the brake lines too with braided stainless steel ones.

I love the XT and the blue colour,(get quite a few comments on the colour), also have blue riding gear.
I do not want top end just more low/mid end power, obviously I don't want to overdo it and have to strip down the engine every weekend but just improve things a few HP.
It was 33 BHP at the rear wheel before I fitted the current silencer, Ideally I would like 40-45 which I think the XR has at the rear wheel (61 camshaft)from looking at some old dynos.

Tenere Tom 11 Jun 2010 23:49

From experience more cc=more power but when you run out of cc and still want more power then you have to start making things run better and more efficient , this is usually carburation and/or tuning the engine.

It's just a matter of getting more fuel/air into your cylinder and getting it to burn at it's best.

A ported head and a good carb setup will work wonders, it takes time to get it right but the results can be very rewarding.

03XT600E 12 Jun 2010 08:10

I think a bigger piston, getting the cylinder head rebored and a 660 from Kolben might be what I need then. Also a camshaft.

Tom would the ported head you have be suitable for after I have had the head rebored or only for what I have on the bike now?

Tenere Tom 12 Jun 2010 15:35

It would suit either. The size of the piston won't affect it.
Obviously a bigger piston is going to offer more power.

03XT600E 14 Jun 2010 22:49

Is there room to get the cylinder bored out to 101mm for + 6mm piston? Or would I need to get a sleeve?

Forget that wiseco tell me there is no 101 mm big bore kit for the XT600 after 1996, a few retailers told me the same.

Jens Eskildsen 15 Jun 2010 16:33

You need a new sleeve for anything much over 1-2mm.

Kedo has a 671ccm (ish) bigborekit, its 101mm and with compression around 10-11 as I recall. It should fit al xt600e and probably more.


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