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2012 KTM 300XCW S-3 Head or Not ?

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1st: I have searched... Anyone have experience with the S3 head and SX Ignition? would this be a better improvement in Low-to Mid than a Gnarly pipe? I'm looking to improve the Low-Mid response.. looking for smooth from the very bottom up to mid. The S-3 head looks nice in orange, not sure if I would need a XC or SX ignition with it ? I suppose the SX CDI is what everyone is running ? Just looking for opinions & input on those products. I have it jetted almost perfect, mileage is great, very happy, probably shouldn't even mess with it. Or maybe I should just add a Gnarly pipe and be done.

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I cant comment on a Knarly pipe, as I don't have one .

I do have the Slavens S3 head on my 15 300 xcw though.. and highly recommend it .

For the money and how quick and easy it is to install .. its a must have imo.

If you are looking for low end to mid grunt, yet smooth tractor torque ,the S3 head is the ticket.

I immediately noticed how much off idle grunt it had and how much harder the bike was to stall on the super slow speed technical trails when your riding down near idle speed and just off idle. The 300 already excels at this type of riding with its awesome torque ... but the S3 head made it noticeably stronger . Just go ahead and get one , you wont be sorry.

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I've got a '12 300 xcw, the best thing that I did to improve the low to mid spread was to install a JD jet kit.  I've also been running the red PV spring 1 turn in from flush and coming off of an '08 RM250 my 300 doesn't have a hit and it pulls from bottom to top.

 

Do the cheap stuff (like this) first, you may be surprised.

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Its really not the S3 head that does anything, its just the head work done to it thats specified by Slavens. The big thing I see as a benefit for the S3 head is that its supposed to have increased coolant volume through for lower temps. Other than that you might as well get the standard slavens head for $100 less.

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Does the added grunt from the head make it hard to handle in the tight stuff it steep hill climbs? I feel like it will make it too snappy but I have never tried one

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Does the added grunt from the head make it hard to handle in the tight stuff it steep hill climbs? I feel like it will make it too snappy but I have never tried one

Grunt is typically a slang term for torque.  Added torque is very different than change of power characteristics.  Your PV is going to change power characteristics the most.  More torque is just going to give more usable power everywhere.

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Does the added grunt from the head make it hard to handle in the tight stuff it steep hill climbs? I feel like it will make it too snappy but I have never tried one

No , I found the exact opposite . It made the bike much easier to handle in steep technical stuff because of the extra torque.

It did not not add any "snap" really at all . It just made the low rpm power more useable on slower speed technical climbs.

Its really amazing how hard the bike is to stall now .

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No , I found the exact opposite . It made the bike much easier to handle in steep technical stuff because of the extra torque.

It did not not add any "snap" really at all . It just made the low rpm power more useable on slower speed technical climbs.

Its really amazing how hard the bike is to stall now .

I ride a lot of tight technical trails and I am yet to have my bike stall out on me. The added power is sounding good to me, I just wouldn't want to get the head if it is going to make the bike real "snappy". It sounds like the head gives it more "4 stroke" type of power

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No , I found the exact opposite . It made the bike much easier to handle in steep technical stuff because of the extra torque.It did not not add any "snap" really at all . It just made the low rpm power more useable on slower speed technical climbs.Its really amazing how hard the bike is to stall now .

Did you add an SX CDI or are you running the stock one? I wouldn't mind trying the S3 head if that's all I really need.

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Why wouldn't you just reduce the thickness of the base gasket? This will change port timing, increasing low-mid, and also raise the compression ratio, further increasing low-mid. As long as you measure squish and you're within acceptable limits for the fuel you're running it just seems wise to me to try.

Edited by Eddie8v

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Did you add an SX CDI or are you running the stock one? I wouldn't mind trying the S3 head if that's all I really need.

No the bike is bone stock other than the S3 head.

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Why wouldn't you just reduce the thickness of the base gasket? This will change port timing, increasing low-mid, and also raise the compression ratio, further increasing low-mid. As long as you measure squish and you're within acceptable limits for the fuel you're running it just seems wise to me to try.

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I experimented with this, it did exactly as stated! Lil more grunt & mid, a lil less up on top, but if you never ride there it mite be a good trade off,

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No , I found the exact opposite . It made the bike much easier to handle in steep technical stuff because of the extra torque.

It did not not add any "snap" really at all . It just made the low rpm power more useable on slower speed technical climbs.

Its really amazing how hard the bike is to stall now .

did you lose any top end w/ head? What elevation are you riding at mostly?

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Will I have to change my jetting at all when I change the head?

I am really not sure if you need to change the jetting .

Me and a buddy both bought our bikes new the same week . he dug into the jetting day one and dialed his in .

I was riding mine with stock jetting and it seemed ok .. little blubbery off idle .. but really not bad at all .

Then we both ordered the s3 heads . He put his on and raved about it.. I went over to his place to put mine on..

and while we were at it he said he'd change my main jet to the one he had on his. he had already done the trial and error thing and figured he had the jetting figured out .. sorry but I can not remember what jet he put in . I remember him saying it was

only 1 or 2 sizes away from stock . bigger or smaller im not sure . Lol.

It does feel like I may have lost a very slight amount of top end .. so slight that it may be in my head and I am just getting used to the power of this bike now .. But if I did lose any it was minimal, and what I gained in bottom end and mid power more than makes up for it . I rarely ride in the top end of the rpm range . I also rarely get out of 3rd gear in the tight single track stuff I ride.

I mostly ride in the 2500 ft to 4000 ft range and on occasion up to 7-8000ft

Sorry I cant tell you my jet size .. I realize that's a big part of the equation . I had never had a carb apart in my life .. so when my buddy offered to change the jet I gladly let him go to it.

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I didn't end up changing the jetting on mine ('15, 300)  but I did turn in the airscrew 1/2 turn.  Sometimes I'd get a bit of decel knock when shutting down the throttle from a high RPM run, long straight-tight corner type of thing.  it's because suddenly slide shuts down cutting off most of the fuel and when you add the high compression sometimes it'll knock a little, turning in the AS gives it a little more juice at that point.  Of course if you add a little race fuel the problem suddenly disappears.  It's not a big issue. 

 

The head was the best bang for the buck to take away the lazy off idle feeling on my xcw, I ride technical trails so often it's a gear high.

 

My buddy also runs the S3 but lives up in CO so he runs the 6K'+ insert, I run the lower alt insert.  We swapped bikes recently so I got a back to back compare with the different inserts.  The high alt insert definitely had a little more off idle but lost a noticeable amount off the top, the low alt insert pulled it cleanly in a run.  IMO the bottom end improvement on the high alt wasn't worth the loss up top.      

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My opinion is you would be better off first putting in the thinnest base gasket then shaving the stock head to get the correct squish and then dial in your jetting and spend some actual time on it testing and adjusting. Then if you really need more add one or two teeth to the rear but I don't think you will need too. I don't think the Gnarly is a good pipe for a KTM 300 the PC platinum 2 with a PC 304 is the best running pipe/silencer I have found on a KTM 300.

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