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Drz400sm stoker build question

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I have a Drz400sm and new to put a new crankshaft in it. Was going to put the Hot Rods +4 mm stroker crank in with a yoshi rs2, fcr mx 39 carb, and do the 3x3 mod. Do to money constraints i was going to add the CW 434cc big bore and a set of stage 2 or better hot cams. My question is splitting it like this better? Will i need to do any head work to the bike and is the fcr 39 okay for when i do that big bore kit? And how reliable is big bore/ stroker kits on the drz? probably been answered before just would like a updated answer. thank you.:)

and are there any other recommended cams to get for it

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You can use a 39 but if you are looking to maximize the build a 41 would be better. If you already have the 39 you can have it bored out for a few hundred bucks if you decide later on you want more. The Yoshi exhaust will be a big restriction, a MRD Z pro or SSW would be better. I'm pointing out the Z PRO or SSW because at one time(maybe still) MRD also had an standard exhaust with only a 2" mid pipe and core(ZPro is 2.250") Some people assume they are all the same.

 

Hotcams are made for 400cc and even then they aren't that big. If your going 462cc you should go Web 540/539 or larger.

 

 

 

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Dude thank you so much lol. How would the 41 do while I'm in between getting the big bore? And gona have to look into the exhaust and the cams.

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For sure yea I'll get one and I'm looking for just all around power gain while staying reliable. I ride the bike everyday to work and I wheelie it everywhere lol

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I have the 470cc stroker kit, fcr39 carb, yoshimura exhaust., open airbox, stage 2 hot cams. I have had the stroker kit in it for a bit now with no issues. You will not need head work done to make it work, although if you are wanting to get the most out of your bike its not a bad idea to talk to your local machine shop. i would go with a  different exhaust if possible, if not, what you have works just fine. The difference after all is said and done is amazing, this bike is a ton more fun when you spend a few bucks on it. 

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Okay cool. What do you guys think about the CW big bore kit? Never heard of vortex pistons, that's what is kind of making me think about it.

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Okay cool. What do you guys think about the CW big bore kit? Never heard of vertex pistons, that's what is kind of making me think about it.

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Okay cool. What do you guys think about the CW big bore kit? Never heard of vortex pistons, that's what is kind of making me think about it.


The Cylinder Works kits is proven time and again to be reliable.

Vortex pistons are high quality and actually OEM on KTM's. They are available in incremental A, B ,ect sizes like some OEM pistons and matched to the bore of each individual CW cylinder.
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Piggybacking off this topic:

I've got the BB +stroker parts laid out now, and am trying to figure out the head gaskets. I've got the 3 layer cometic ones now, but I see people running 4 layers. Is that just a 3 layer +1? Also, to run a 4 layer, is a cylinder spacer required?

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3 layer for 11.3CR, single for 12.5 CR.  Cylinder spacer was needed for the unavailable 5mm stroker crank.

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1 hour ago, 38super said:

3 layer for 11.3CR, single for 12.5 CR.  Cylinder spacer was needed for the unavailable 5mm stroker crank.

Isn't 11.3 CR with a 3 layer only for the cylinderworks BB kit alone and not with the stroker?

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On ‎7‎/‎15‎/‎2017 at 3:22 PM, Brogeezie said:

For sure yea I'll get one and I'm looking for just all around power gain while staying reliable. I ride the bike everyday to work and I wheelie it everywhere lol

One thing that isn't mentioned here is how loud and obnoxious do you want your bike ? The MRD is the loudest pipe you can put on it for the little gain up top . For riding in towns , daily commuting, I would go with the Yoshi , I have the FMF P4 and it's too loud IMHO already, only way you'll notice the power loss is on a dyno . Once you get out of this forum I've now seen a bunch of people turning around and selling their MRD to get something that they can stand riding , it all depends on what your interested in or don't mind putting up with. Straight up topend peak hp = MRD ,  sanity = Yoshi & FMF .

 

.

Edited by jjktmrider
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+1 MRD is extremely loud. I use earplugs and don't like riding with my friends who have that pipe. I have the FMF and like it, but the Yoshi fits better.

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Loudness is a relative thing. Compared to the average middle aged lawyer on a Harley, the MRD is whisper quiet. The stock pipe on my YZ250F is also louder than it.

 

Going from a White Bros, Yoshimura RS3 and finally a MRD, I don't think it was as much of a change in decibels as it was tone. Keeping fresh packing in a silencer is important and makes a huge difference. I guarantee most people aren't repacking as often as they should.

 

From my prospective as someone accustomed to MX and MX tracks, the MRD is average compared most 4 strokes at the track.

 

 

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