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SDR_rider

2020 YZ125X first impressions and review

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On 2/29/2020 at 3:15 PM, SRD_rider said:

1: Keihin 36mm carb. Better off idle response and easier to jet.

I think you answered these questions in the past, but sorry I couldn't find it ... 

Are the PWK36 entry and exit ports the same size as the stock Mikuni or just close enough?

Are all PWK36 carbs "short body"  or do I have to be careful which one I get?

If you know the PWK36 port outside diameters and the length overall that could help. thanks.

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43 minutes ago, numroe said:

I think you answered these questions in the past, but sorry I couldn't find it ... 

Are the PWK36 entry and exit ports the same size as the stock Mikuni or just close enough?

Are all PWK36 carbs "short body"  or do I have to be careful which one I get?

If you know the PWK36 port outside diameters and the length overall that could help. thanks.

I'm using the short body carb were on ktms before they switched to mikuni. Same size as the mikuni so it's a direct bolt on. I'm even using the same throttle cable. If you can't find a KTM takeoff JD jetting sells them new.

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Are the ktm mikuni needles the same as the yam ones ? I have a bunch of ktm needles left over from my 150xcw so wondering if for example the ktm / mikuni 44-74 would be the same as the yam 44-74 ? 

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5 hours ago, Burger72 said:

Are the ktm mikuni needles the same as the yam ones ? I have a bunch of ktm needles left over from my 150xcw so wondering if for example the ktm / mikuni 44-74 would be the same as the yam 44-74 ? 

I do believe they are the same. 

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On 3/8/2020 at 4:00 AM, SRD_rider said:

I'm using the short body carb were on ktms before they switched to mikuni. Same size as the mikuni so it's a direct bolt on. I'm even using the same throttle cable. If you can't find a KTM takeoff JD jetting sells them new.

Hi 

How would describe them Keihin compared to the mikuni ? Does it have a noticeable better bottom end when you swapped ? I’ve never been a fan of Lectron carbs but a couple using them on the yz seems impressed with the increase in bottom end..... 

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17 hours ago, Burger72 said:

Hi 

How would describe them Keihin compared to the mikuni ? Does it have a noticeable better bottom end when you swapped ? I’ve never been a fan of Lectron carbs but a couple using them on the yz seems impressed with the increase in bottom end..... 

The bottom end, off idle power/ response was improved with the Keihin. Jetting was more stable over temp changes to. The big problem I had with the mikuni it was very temperature sensitive making it very hard to jet. I'm not a lectron fan either. Had two of them and both had issues. 

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Ok so my X has a slightly annoying throttle bog .....

some background, 2020 X amazing bike absolutely in love with it, from day 1 I have had a Dep Torque front pipe fitted apart from that it’s stock including the silencer, in the U.K. with temps around 10c and at sea level, running stock jetting but with a 37 pilot and and it flys but ..... if I come to a stop and then wap the throttle wide open it bogs deep , it won’t do it in the stand you can snap it fully open as fast as you like and it’s super clean but when on it it will bog out, if I’m rolling a little at a slow jogging pace and above it’s fine but I don’t want to have to use the clutch to get past it every time, 

I’ve tried going richer on the pilot and needle and clip positioning and in and out with the air screw but it just won’t budge, it’s better when it’s on a richer setting but it’s far to rich everywhere else and still doesn’t clear it completely. 
Im thinking it must be the pipe unless it’s a common issue ? I know the Mikuni gets a bad wrap but I have the jd jet block kit fitted and a few mods and have had these working really well in the past .....

Had anyone else experienced this ? Like I say it’s when you riding and come to a stop as if you about to blip over a log, go “wot” and the bog is there ......

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2 hours ago, Burger72 said:

Ok so my X has a slightly annoying throttle bog .....

some background, 2020 X amazing bike absolutely in love with it, from day 1 I have had a Dep Torque front pipe fitted apart from that it’s stock including the silencer, in the U.K. with temps around 10c and at sea level, running stock jetting but with a 37 pilot and and it flys but ..... if I come to a stop and then wap the throttle wide open it bogs deep , it won’t do it in the stand you can snap it fully open as fast as you like and it’s super clean but when on it it will bog out, if I’m rolling a little at a slow jogging pace and above it’s fine but I don’t want to have to use the clutch to get past it every time, 

I’ve tried going richer on the pilot and needle and clip positioning and in and out with the air screw but it just won’t budge, it’s better when it’s on a richer setting but it’s far to rich everywhere else and still doesn’t clear it completely. 
Im thinking it must be the pipe unless it’s a common issue ? I know the Mikuni gets a bad wrap but I have the jd jet block kit fitted and a few mods and have had these working really well in the past .....

Had anyone else experienced this ? Like I say it’s when you riding and come to a stop as if you about to blip over a log, go “wot” and the bog is there ......

Maybe jd jet kit or just get the keihin pwk 36 Ag. The 125X I rode had the 36 pwk installed and no issue like you’ve described. 

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Posted (edited)

Installed 2020 YZ 125X CDI on my 2013 YZ 125....noticeable improvement in tractability, depth of power when RPMs drop. Recovers sooner. Accelerates harder thru mid range. Still runs on top! Much better powerband for single track. 125X power valves coming today.  Stock YZ 125 compression and governor spring. This thing RIPS! Exactly what I was hoping for. Best $150 spent!!!

2013 YZ 125:

96 octane - 4000-6000 feet

38mm Keihin PWK: NECW, clip #2, 42p, 1.5 a/s, 175 main, 6.5 slide with notch (extensively tested between OEM Mikuni, 36 PWK, and 38 PWK, Prefer 38 PWK)

V Force 4R

Wiseco Forged Piston Kit – STD

Squish at 1.15 

Steahly 7oz. flywheel weight

FMF Turbinecore 2.1

2020 YZ 125X Ignition Module (CDI)

Other Bikes Owned: 2019 KTM 250 SXF  --  2018 Husqvarna TE 150

Edited by Tuner
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5 hours ago, Burger72 said:

C81CEACC-F8BE-4564-9BCF-372BF657ECED.jpeg

You’re bike is too nice to get dirty! Well done, good Sir.

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Hey I was wondering if 125X owners would be willing to share their jetting and specific carb settings? Along with where they ride i.e. avg. temp and elevation.  

I feel like this could be helpful as I have seen a lot of variation throughout this chain.

I am currently running the stock Mik 38 and ride in South Carolina and Georgia for the most part-at or around sea level.

I currently have a 35 pilot, 43-75 needle 3rd clip, 430 main and air screw around 2 turns out.  I'm not 100% happy with it at this point and I think the needle may be a tad lean, but I have three others to try.  Still experimenting but for now I have been running Super M 32:1 w/93 pump gas and octane booster.  

Any suggestions would be greatly appreciated, as I am also thinking about grabbing a lectron or Keihin.

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3 hours ago, mxhenz said:

Any suggestions would be greatly appreciated, as I am also thinking about grabbing a lectron or Keihin.

I’d go jd jet kit and jet block gasket or keihin. Lectron is iffy on success - typically 50% don’t eventually resell them. I’d also opt for ethanol free fuel if you can fairly easily locate it. 

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4 hours ago, shrubitup said:

I’d go jd jet kit and jet block gasket or keihin. Lectron is iffy on success - typically 50% don’t eventually resell them. I’d also opt for ethanol free fuel if you can fairly easily locate it. 

That really surprises me. My Lectrons have been fantastic. I love them. I think they're perfect for a 125. I had one on my 250 and couldn't get that as spot on, but still better than stock. I don't think I'd get one for a 250 again, but on a 125, most definitely.

 

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16 minutes ago, Drop-Bear said:

That really surprises me. My Lectrons have been fantastic. I love them. I think they're perfect for a 125. I had one on my 250 and couldn't get that as spot on, but still better than stock. I don't think I'd get one for a 250 again, but on a 125, most definitely.

 

I’m with you on the Lectron. It’s almost plug and play for me with 1 tweak and I never touched it after. Hands down, best mod for me matched with the Rad Valve.

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1 minute ago, crujones7 said:

I’m with you on the Lectron. It’s almost plug and play for me with 1 tweak and I never touched it after. Hands down, best mod for me matched with the Rad Valve.

I ride Suzuki, RM's. But exact same experience for me. One adjustment. All smiles.

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On 3/26/2020 at 2:37 AM, Burger72 said:

C81CEACC-F8BE-4564-9BCF-372BF657ECED.jpeg

Okay Burger; fill us in on your lighting setup. All the juicy details!

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Hi chaps 

Ok carb first 

stock mikuni 

JD jet block gasket and O-ring fitted 

Full Jarvis mods carried out.

small notch in the slide, sump bolt drilled to match up holes on the body, splash guard holes enlarged slightly, overflow brass pipe crimped partially closed, float height set around 6-7mm 

The Jarvis mods help a lot don’t be fooled into thinking it’s nonsense, it works this is the 3rd bike with that carb on I’ve done it to.

im running stock needle in clip 3 , 430 main, 37.5 pilot, as 2 turns out.

temps are around 10-12c and between sea level and a hundred foot or so elevation.

Standard Pump fuel mixed at 40:1

 

As for the lights I just hate the yam front headlight it’s but ugly to me so I went with a ktm 2020 headlight, it fits nice and I’ve secured it to the top of the front fender with 2 small pk screws through the bottom of fender into the two pegs on the bottom of the headlight mask.

The rear is an Acerbis led tail light add on. Neither are wired up yet as I’ll never use them I just wanted it to look more “enduro” then XC 

Skid plate is also Acerbis and fits superbly, Dep factory front pipe but I’ve since gone back to the standard Yam one, lastly I’ve just had a custom front brake hose made which is longer and fits through the front of the headlight mask as it should because the stock was to short to clear it and had to run behind which was snagging 

D3ECA224-55D3-4460-A1EA-23980689E027.jpeg

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