Top end/RB carb & Head mod//FMF pipe & Silencer

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summitrider04
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Top end/RB carb & Head mod//FMF pipe & Silencer

Post by summitrider04 »

Planning on doing the top end soon -

After researching on this site, both the Pro-X or Weisco piston kits seem acceptable. I'm going with the Pro-X because from what I've interpreted is that somewhere on my cylinder a letter is stamped (A - F) and I can purchase the corresponding Pro-X piston.

I would like to send my carb and Head to RB designs at the same time since I will have the motor apart. I will buy the 607 Boyeson Reeds also.

My questions are:
1. Is it OK to only do the RB head and carb mod without doing an aftermarket Pipe and Silencer? ...Or should I save up more money and do them all at once?

2. If there is a letter stamped on my cylinder, where is it located?


Thanks,
Jon

---
Not sure if these are showing up in my signature:
2003 KDX 200
Stock Jetting
13/49 Renthal Sprockets Renthal works chain
Riding at Mendocino Nat'l forest primarily - 1500-4500 ft, 50-90 F
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fuzzy
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Post by fuzzy »

1. Yes. In fact my next KDX will be done just like that. I want the heavier, yet ultra quiet exhaust.

2. Dunno...There's only a couple stamps on there. I'm guessing it's right next to the displacement notation that's cast in.

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Julien D
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Post by Julien D »

It will not be stamped a through f. You need to measure the bore and order the correct pro-x piston based on that measurement.
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plb
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Post by plb »

My questions are:
1. Is it OK to only do the RB head and carb mod without doing an aftermarket Pipe and Silencer?
My KDX220 setup is:

RACE:
RB-Designs head and carb
VForce3
FMF Rev/Desert with FMF POWERCORE silencer

RIDE:
RB-Designs head and carb
VForce3
FMF Rev/Desert with STOCK silencer

I can't realy feel a difference.
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fuzzy
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Post by fuzzy »

The real layman's way is...Pull out a C, install a D....etc. These super-minute sizes are to make up for the microns that wear off the plating while the piston/rings wear out.
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scheckaet
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Post by scheckaet »

You don't gain real power by adding aftermarker muffler, but you will save weight...and a bit more noise.
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Post by Indawoods »

Just take a big dump... now it's equal! :mrgreen:
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summitrider04
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Post by summitrider04 »

The real layman's way is...Pull out a C, install a D....etc. These super-minute sizes are to make up for the microns that wear off the plating while the piston/rings wear out.
I like this approach.


Thanks for the input guys
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TWMOODY
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Post by TWMOODY »

Put that pipe on there FIRST or at least do that and the carb/head together.
Your bike will wake up just by putting the pipe on it.......
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Post by plb »

In priority:

1- FMF Rev/Woods or Pro Circuit expension chamber
2- RB-Designs head and carb
3- VForce or Boyeson
4- Aftermarket muffler FMF/Pro Circuit, etc.
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fuzzy
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Post by fuzzy »

IMHO:

Susp first.
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Post by summitrider04 »

IMHO:

Susp first.
Haven't installed it yet, but I have a Race Tech shock spring 4.8kg. I probably weigh a little under 150 lbs with gear on. I know on Fredette's website (where I took his advice on the shock spring) it says I should install the .38kg fork springs for my weight but the stock springs feel fine for now.
Put that pipe on there FIRST or at least do that and the carb/head together.
Your bike will wake up just by putting the pipe on it.......
I'll probably save up the extra $250 and do this since then I can tell RB designs what I have and they can try to jet it properly. I understand jetting isn't a 'set it, and forget it' thing but I'd be bummed if I installed the Pipe down the road and had to do all he trial and error.
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Post by plb »

IMHO:

Susp first.
I agree. I have a KX125 front fork with Race Tech Gold Valves enduro setup on the fork and on the shock. Awesome upgrade.

But my previous answer was about the motor.
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Post by jbowens2401 »

On Ron's website he recommends you have an aftermarket expansion chamber for his mods to work properly. I spoke with him when doing mine and he said the silencer isn't necessary.
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Post by AtomicKDX »

I agree -> suspension 1st, esp the forks.

next -> aftermarket exp chamber

next -> head & carb both

then -> reeds

pipe? -> no (take a dump before hand)

>|<>QBB<
fuzzy wrote:IMHO:

Susp first.
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Julien D
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Post by Julien D »

Sounds about right. You won't believe the difference a good expansion chamber alone is gonna make for you.
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summitrider04
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Post by summitrider04 »

Holy crap my bike rips! Finally got around to doing some mods. I did the top end and went with a wiseco piston. Changed to VForce3 reeds and added the gnarly woods pipe. Re-jetted to 155 main/45 pilot and also took the airbox lid off (or cut it so the wiring harness can stay put). Yes it's a lot of mods at once but now I can lift the front wheel off of just about every bump in the trail! I was still able to drain a bunch of spooge out of the (stock) silencer at the end of the ride, but nothing was "dripping" out of the tail pipe onto my brake caliper like it used to, just a little wet. Running 32:1 Maxima super M for this tank and then switching to Motul 710.

I'm definitely going to send my carb to RB when I save up some more $$.

I want to thank everyone on this website for all the great knowledge.
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Post by SCREAM »

imagine if you took a big dump and swapped out the stock silencer! you'd be flying. :shock:
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Post by rbates9 »

>|<>QBB<
SCREAM wrote:imagine if you took a big dump and swapped out the stock silencer! you'd be flying. :shock:
I tend to do the first part before every ride just for that reason! :grin:
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