When you do go with the 351 the cams need to go back to stock. I plan to do the 351 soon and may return the intake to stock and leave the exhaust modded. I recall reading somewhere in the cam mod post that marcelino said the modded intake will definitely not work with a big bore, exhaust might work. Maybe zomby-woof can give some insight on this as he is a cam guru. Either way it's worth a try, otherwise i will have to retime the ACR again.

 

I recall reading that I will have to reset the cam timing too. Simple enough. I only wish I had marked the ACR BEFORE I moved it. Now I will have to re-time it the hard way!
I plan to try the big bore kit without the new carb as a baseline for comparison. If runs like I want I may just leave it. If not, I will spring for the carb. Also planning to install an IMS tank to feed the big guy too.

 

Haven't cut the screen out yet.
I should add that I came to the KLX from a WR250F that would lift the wheel anytime, with ease. The KLX, now, will pull well but not nearly as hard. That has been the price I paid for a plated bike.[/QUOTE]

I would not bother too much with the screen, a lot of work with no noticable benefit on seat of pants Dyno. If someone can produce positive before and after Dyno results I would do mine again.

I am sure you miss the WRF. The things I miss the most about my last 250 MX bike was replacing shredded back tyres, streched chains and the joy of rebuilding the top end every 6 months.

 

Yeah, I loved that possibility with the WRF. Didn't keep the WRF long enough to shred the rear tire - but it was getting there! Until I get a KLX big bore I won't be shredding any rear tires! side note: I have a Pirelli MT43 Trials rear tire to put on soon. Supposed to grip well on dirt and street with 8 to 10 lbs.

 

The screen removal on my KLX required that i fatten up the jetting. If it made no difference than i suspect the bike would have run fine and not required more fuel. It is a pain to remove the screen, and i suspect different bikes (wrf) react differently to screen removal.

 

To clear benefits obtained Marcelino modification must be made with the motorcycle camshafts from the year 2009 and beyond. Ref: 12044-0175
In models with engine capacity of 250cc is where greater benefits are obtained.


In the 2009 models with displacement increased to 300cc the method works, but personally I like to make the change only on the intake cam.


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With the exhaust camshafts ref 12044 1487 I have not benefited by the change.



Left 2009 KLX250, ref 12044-0175
Right KLX300 2002-2007) ref 12 044 1487

 

You say this only benefits 2009 newer KLX's?
I have the 2008, was going to do this mod.

With the full headers and all mods done so far, the bike is night and day difference, it now declines like crazy in every gear and now rides more like a dirt bike. I was going to toss in new cams, see what difference it make.

 

Not that the change in his motorcycle in 2008 does not work, but I suspect it will do better even with cams 2009 models.

And of course always seen an improvement in the 250cc models. As displacement increases the benefits appear to decrease slightly.

Do not forget you can also make the change to half, ie, only the intake cam, in this way is less complicated and does not need to modify the ACR.

 

Thanks, ill do it. Any little extra is nice to have. Great post and directions!

 

How do you set up the timing if you only do the intake cam?
any fotos?