Posts: 460
Joined: 12/22/2010
Location: CA, USA
Edited Date/Time:
YZ325
http://www.eddie-sanders-racing.com/product_p/yz325.ceo.cylinder.kit-.htm
You can see photos of it in the trx add.
http://www.eddie-sanders-racing.com/category_s/171.htm
Sweet seeing some innovation in the 2 stroke world. Patent pending. It says "Incredible bottom end and top end power. Nothing close. Comes on the pipe without hesitation. Power band feels 3 times wider" This will be something to watch.
Posts: 881
Joined: 3/28/2013
Location: Chandler, TX USA
Is it the piston, or the big bore? I like to build big bore bikes, as my buddies know lol. The power feels so much better the stock. Would like to see test vs stock bore.
Posts: 830
Joined: 1/11/2017
Location: CAN
Posts: 1235
Joined: 7/19/2018
Location: Wildomar, CA USA
Edited Date/Time:
racingfortheson wrote:Is it the piston, or the big bore? I like to build big bore bikes, as my buddies know lol. The power feels so much better the ...more
It is the big bore kit that increases the power, not the piston design so much.
Posts: 317
Joined: 9/20/2011
Location: Sedro Woolley, WA USA
ESR has been around forever from the micro sprint days in the 90s. We were taking CR250s and bore and stroking them on methanol . Clutch gone, power valves gone, huge pipes and replaceable domes and a host of other shit. Was getting close to 90 HP out of a 270cc honda engine. They still race them back east.
It's all in the squish... ( post piston to dome clearance)
Was once there, now old, fat and tired... require much more horsepower now...
Posts: 460
Joined: 12/22/2010
Location: CA, USA
Posts: 1197
Joined: 4/1/2008
Location: Trail, CAN
"Powerband feels three times wider"... if it sounds too good to be true....
Not saying it can't happen, but that's a pretty big claim.
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
YZ ESR 325 is awesome, similar to a 450 but not as broad of a power band!
Might be worthwhile to upgrade.
SDT-YZ ESR 325
Keep It Simple Stupid (KISS)
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Setup:
Yamaha YZ Eddie Sanders Racing (ESR) 325 Build (2007)
Purpose - Motocross and Off Road rider – Intermediate Level
-Eddie Sanders Racing (ESR 325 - S7 (Woods Porting), Race Gas Dome (use 50 Pump/50 Race Fuel) ($900)
-No - Fly Wheel Weight - None
-Race Tech Suspension ($600)
-Moto Tassinari Reed Valve ($250)
-Rekluse Clutch - Core EXP 2.0 ($900)
-ESR Expansion Chamber ($200)
-FMF Q Silencer ($100)
-Vortex Ignition ($250)
-Dunlop MX 3S 90/21 Front, MX 33 Rear - 120/19
-TU-BLISS -Traction Control System ($200 Total)
-Geared 14 – 48
-Jetting 165 Main, 42 Pilot (Works in 500” to 4,000’ Altitude)
$3,500 Used 2007 YZ 250, plus parts $3,450 = $6,950
SDT-YZ ESR 325
Keep It Simple Stupid (KISS)
Posts: 2944
Joined: 6/28/2014
Location: AUS
Interesting: Concave Piston
I wonder what the head shape is - Flat, or curved to mirror the piston profile, or any number of other designs?
I signed up to his newsletter, as I'm interested in the PV Cylinder he's got coming for the CR500. I'm not sure of his design - perhaps (well, likely) it's the CV / Diaphragm type I so liked on my Maicos. Or, better still, just vacuum without a diaphragm. Simple, though, of course, far more complicated than just a plain port 
. The basic simplicity of my 500 is it's great appeal to me, but a PV like the Maicos (and many others that used non 'mechanically linked' set ups) , just scoots into the simple / basic side of the ledger for me.
Posts: 7414
Joined: 10/31/2013
Location: PA, USA
goinrcn44h wrote:ESR has been around forever from the micro sprint days in the 90s. We were taking CR250s and bore and stroking them on ...more
This. My neighbor, across the street, has a wall full of melted pistons from his old 270. Methanol sure makes power...but those dirt track boys sure do scatter a bunch of engines.
Tomac and/or Anderson for 2020.....
Posts: 2299
Joined: 3/18/2016
Location: CA, USA
SDTony YZ ESR 325 wrote:ESR 325 Engine
Tony - I've been in contact with Eddie the last couple of yrs. as I've been contemplating picking up a 325 kit for a 02/07 CR250. The production date has been pushed back a few times in that span, but it shows mid Nov. 2018 on the link above. I've been unable to get in contact with him since this thread got started probably due to the holidays.
With his kits, Do you know if a 250 pipe can be run or do you need the ESR pipe I see on your list of mods ? Can the standard 250 38mm carb be run or does it need to be tapered for a bigger bore size to a 39mm ?
I would think the mods above would help to get optimum performance out of his 325 kits..
Speak softly and carry a big stick.
Posts: 895
Joined: 3/3/2018
Location: FRA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
SDTony YZ ESR 325 wrote:ESR 325 Engine
Yes the stock or FMF pipe (I had the Works and Gnarly) works great with the ESR 325.
The ESR pipe is about 40mm longer and maybe slightly larger diameter, it works better for a 250 or 325 than the FMF, maybe by 15-25% better, not a huge difference but noticeable.
Stay with a 38mm Carb, changing this will complicate things. Stock jetting on a YZ 250 was 170 main, 48/50 pilot, but the ESR 325 sucks harder (33% larger piston) and therefore you go down in Jet sizes. I tired a lot of sizes, but in the end 168 main and 42 pilot.
SDT-YZ ESR 325
Keep It Simple Stupid (KISS)
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Godzilla, mine is the current technology, which is outstanding. I am waiting to see the photo on ESR as well, we will see, ESR has been around for over 25 years.
SDT-YZ ESR 325
Keep It Simple Stupid (KISS)
Posts: 895
Joined: 3/3/2018
Location: FRA
Edited Date/Time:
Obviously the top of the piston is concave...
Don't have a clue what it does, lol...
Neither with the hollow side.
Any good 2 stroke tech around?
Posts: 72
Joined: 1/1/2014
Location: NEO, OH USA
1988-1989 KX125 OEM piston 13001-1266 used a concave crown, there have been others that use this design
Posts: 7414
Joined: 10/31/2013
Location: PA, USA
Posts: 1108
Joined: 5/13/2015
Location: Utica, MI USA
It's pretty simple. The head is either flat or has a reduced chamber volume. The piston needs a dish to get the desired compression ratio. It's not rocket science.
Race Bike: 2018 KTM 350SXF
Other Bikes: 1985 CR80R, 1990 CR250R, 1998 PW80, Yeti SB130LR.
Sold: 2016 YZ250F, 2012 CRF250R
Posts: 72
Joined: 1/1/2014
Location: NEO, OH USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
Posts: 414
Joined: 4/24/2014
Location: San Diego, CA USA
