2010-2013 yz450f motor mods

[2-stroker96]

hey everyone I have a 2012 yz450 and am pretty happy with the bike so far, still getting comfortable with it, just came off a 05 cr250 2 smoke and is a whole different ball game, just got my suspension back from pro circuit, im looking at doing a motor mod either a high compression piston, or looking at doing cams instead, was looking at the gytr cams.  im just wondering if anyone has done any of these mods or which one would be better over the other, bottom to mid is good in my opinion but I really don't like the flat feeling top end, Im wanting to make the motor pull strong all the way from bottom to top so if someone has any advice on the topic id really appreciate it im not really sure where else to look for information, im an intermediate rider, 5'9" 145lbs w/o gear not that that really has any significance to the topic, and ive played with gearing a bit already and have kind of settled with 13/49 

[JLB943]

First question, what do you use the bike for?

 

I use my mainly for motocross with some trail/play riding here and there. I am not that fast so what I like someone else may hate.

 

I have the Hot Cams builder series cams in my bike along with the high compression piston. I also have a full Jardine RT99 exhaust.

A lot of places I have seen said the short-windedness of the bike and be fixed by changing the stock muffler so you may try this out first.

I didn't like the way the bike was when I first got it. It was abrupt and then died on top, Going down straightaways it was annoying. With the changes I have made, I really like the broader powerband,it is so easy to ride now as I don't have to shift as much. Part of the reason I made the changes was from reading this article by MXA where they did a Hot Cams 2010 YZ450 bike and the way the motor was described.(I know magazine sold me on cams I probably don't need.)  

 

I would try the exhaust first, then the cams, high compression piston last only if necessary.

 

 

 

 

 

 

[DDMX18]

I ran the GYTR cams/high comp piston and FMF exhaust on my 2011. On the dyno it gave it about 2hp more, but moved the power higher in the range. If you like 2 strokes and like to live in the higher RPM's then you would like this set up. I ran the GYTR map that is on their website and never had a problem. I'll see if i can dig out the dyno chart if you are interested? Also ran a 51T on the rear.

[raptorgabe]

i have hotcams and a dr d full exhaust and havnt even rode mine yet kinda wondering where to get a tune for my powe commander 5

[mxbrewski]

@raptor, I gave you this already i think   http://www.sisnerosspeedworks.com/

[2-stroker96]

I ran the GYTR cams/high comp piston and FMF exhaust on my 2011. On the dyno it gave it about 2hp more, but moved the power higher in the range. If you like 2 strokes and like to live in the higher RPM's then you would like this set up. I ran the GYTR map that is on their website and never had a problem. I'll see if i can dig out the dyno chart if you are interested? Also ran a 51T on the rear.

I use the bike mainly for racing mx, DDMX18 do you remember what you did for mapping, I have the tuner.  the other thing I wonder is with aftermarket cams, will the valve clearances still be the same as the manual specs.  I also have the procircuit Ti-5 exhaust, so im hoping that plus cams will move the power more so where I want it

[2-stroker96]

probably before I buy anything else im going to try the jay marmont map with the ti-5 exhaust might just be all I need

[DDMX18]

Hey 2-stroke96, Yeah the marmont map will be the way to go with the PC exhaust. If you do decide to go with cams  i ran the normal (stock) clearances.

 

The maps for the GYTR parts can be found on the yamaha website. They were spot on from my experience.

[2-stroker96]

Hey 2-stroke96, Yeah the marmont map will be the way to go with the PC exhaust. If you do decide to go with cams  i ran the normal (stock) clearances.

 

The maps for the GYTR parts can be found on the yamaha website. They were spot on from my experience.

thanks DDMX18 that's exactly what im looking for like I said ill be trying the marmont map and if that gives me what im looking for then it'll save me the money that cams would cost

[Crusty Cy]

13/49 gearing, exhaust, and Marmont or Smooth/ Broad map.  No need for anything else.