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Beta2Stroke RK Tech on a 200rr

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18 minutes ago, HERA said:

The 175 may be too large and this will effect all areas... Try the same with a 168 main.. The N8RG needle is very easy to obtain (2015 KTM 300 XC factory needle). also the STOCk needle will also work fine!!  This set up should not be lethargic at all.

 

okay I'll give the stock needle a go in clip 3 with 48/168 next.

just for reference:  according to the info I have the straight section of the "i" series is 2.735mm and is the same for the "w" series

the straight section for the "g" series is 2.715mm which is 2 steps richer than the i or w series and the "h" series would be in the middle @ 2.725mm

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16 hours ago, Primal Enduro said:

Today I tested JD Blue #4, with 40p and 175m.   Temp was around 70 degrees.   First impressions were that it lost a lot of torque off the bottom, but it did rev through the mid/upper range very clean and power was linear and seemless, but not overly strong compared to what I'm used to.

interesting, thanks for the update. i feel like my bike has great torque, just not refined yet ... i have an N8RG on order but will also test 50/168 on Friday with the stock needle.

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1 hour ago, typeone said:

interesting, thanks for the update. i feel like my bike has great torque, just not refined yet ... i have an N8RG on order but will also test 50/168 on Friday with the stock needle.

Perfect!!! Keep us all posted..

Remember, we are looking for low end "crawling" ability, NOT "quick revving" ability. Great test is to put it in a high gear(higher than you normally ride) and traverse some terrain without having to drag the clutch (as much or at all) or down shift..  You will also notice the ability to lift the front end (like onto a log or rock) at a very low RPM vs having to rev the engine to a higher RPM to get the front end lifted.. This also applies if you are using the clutch to help lift the front end... LISTEN to the engine RPM and notice how low it is vs needing to rev higher..

Looking forward to the results..

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The N8R* is the 1/2 clip leaner cousin of the N2Z*, FWIW.

Stock in Beta 250/300s and KX250s back in the day I believe.

Different taper structure, generally more hit than the NEC/D series, all else being equal.

Of course try what the developer suggests but I think you will like the other series a lot with the proper dia. 

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49 minutes ago, HERA said:

Perfect!!! Keep us all posted..

Remember, we are looking for low end "crawling" ability, NOT "quick revving" ability. Great test is to put it in a high gear(higher than you normally ride) and traverse some terrain without having to drag the clutch (as much or at all) or down shift..  You will also notice the ability to lift the front end (like onto a log or rock) at a very low RPM vs having to rev the engine to a higher RPM to get the front end lifted.. This also applies if you are using the clutch to help lift the front end... LISTEN to the engine RPM and notice how low it is vs needing to rev higher..

Looking forward to the results..

cool, will post impressions ... i have great torque in the lower RPM range with the RK head, have been surprised by dug out roots at the top of blind climbs and a simple twist of the throttle has lofted the wheel to clear the root, even when on a sandy hill. very curious to see if this torque increases with the 50/168 + stock needle. if it does, i'll be extremely impressed.

keep forgetting to mention, and i don't know how much it matters, but i also have a Thunder Products Torque Wing installed. ran one on my 250 and liked it so i added to the 200 a while back. installing a wing has always seemed to clean up/improve power right off idle when crawling up hill for me. 4th bike i've added one to.

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On the N8 needles.After much trial and error I ultimately decided on the N82M needle which is an old KX500 application.Works very,very good on my not so stock 250,Shaved head,shortened can and a hot GG XC cdi.The carb is modded too with a torque wing and Mikuni power jet kit addition. 38 pilot ,150 main and 40 power jet.Forty being the mik jet I used converted into Keihin speak.1500 to 4500 feet elevation.I might have to try that needle in my 300 with the 39 mm power jet carb although the N0ZJ works very well.Both bike run 14-48 gearing and pull cleanly right down to idle.

Edited by Odysseus

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On 10/15/2020 at 8:35 PM, Primal Enduro said:

IDK,  I must be doing something wrong, I can't get mine to the sweet spot.  I've tried extremely rich jetting per Hera (48p 175 main...he wanted 50 pilot but 48 was the largest I had) and had no bottom end.  Last weekend I rode with 45/170 stock needle in the 3rd and it felt pretty good at ~50 degrees.  Tonight at ~75 degrees it felt like I had potato stuffed in the tail pipe.  could come on the pipe easily at all.  Hera keeps saying go richer, but I'm not getting the results.  I'm thinking about going back to the stock head soon.

Last Thursday I rode the stock needle in the 3rd with 45/170.  Tomorrow I will try the same needle/clip with 48/168 per Kelsey and report back.  

 

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I hate to be hijacking this thread (lmk if I should start a new thread instead): But can folks using the RK tech head post about what jetting they were using prior to rk tech and what was the sweet spot after? I am planning to get my head cut by rk tech for my 250RR. I am at sea level, riding temps 60-90. Float height set; currently running JD jetting kit: 38p, blue #3, 165m. I am happy with this. I am looking for low rpm crawlability much like @Primal Enduro

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2 hours ago, ktm450cl said:

I hate to be hijacking this thread (lmk if I should start a new thread instead): But can folks using the RK tech head post about what jetting they were using prior to rk tech and what was the sweet spot after? I am planning to get my head cut by rk tech for my 250RR. I am at sea level, riding temps 60-90. Float height set; currently running JD jetting kit: 38p, blue #3, 165m. I am happy with this. I am looking for low rpm crawlability much like @Primal Enduro

before the RK insert, i was extremely happy with the JD kit, 38p, Blue #4, 175m ... 40:1 Amsoil Interceptor, 89 pump, stock pipe, open Scalvini silencer, 14/49 gearing, IBEX w/TUbliss ... super goat

~40-90 temps, ~300-1,100ft ASL

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3 hours ago, ktm450cl said:

I hate to be hijacking this thread (lmk if I should start a new thread instead): But can folks using the RK tech head post about what jetting they were using prior to rk tech and what was the sweet spot after? I am planning to get my head cut by rk tech for my 250RR. I am at sea level, riding temps 60-90. Float height set; currently running JD jetting kit: 38p, blue #3, 165m. I am happy with this. I am looking for low rpm crawlability much like @Primal Enduro

My 17' 250RR head is cut (not by RK however) and i didn't have to change my jetting.  Winter, 38p / 168 main, JD BLUE 3.. Spring / Summer i only change the needle.  Red 4 (or Red 3 if it gets really hot).  Belray Si7 44:1, 13 / 51.. @typeone has the super goat.  I have the mega goat 🙂

Edited by NW_drZ
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1 hour ago, typeone said:

before the RK insert, i was extremely happy with the JD kit, 38p, Blue #4, 175m ... 40:1 Amsoil Interceptor, 89 pump, stock pipe, open Scalvini silencer, 14/49 gearing, IBEX w/TUbliss ... super goat

~40-90 temps, ~300-1,100ft ASL

And after?

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29 minutes ago, ktm450cl said:

And after?

i don't have a preferred setup yet, hence all the brass swaps, but the bike runs awesome and has fantastic power. really only fine tuning and testing other combinations at this point. i'm still running the JD needle but want to test stock needle tomorrow, and KTM needle after that.

i'll have to look up my last spec with the 250 but like @NW_drZ, i had that thing ripping ... 6+ years of pure love with that bike ... only reason for the change to the 200 was that i missed the feel + size of my old '09 Husky WR165 on our singletrack here. mountain bike with a motor.

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Just got the head for the 200. Might put it on this week

My current jetting since I got my bike.

Conditions: 6000-9000 ft

Temp 60-80

Singletrack, ATV trails, 

 

1st ride: 45 pilot, 155 main, Stock Needle #3. Ran ok, blurble in the mid range

2nd ride: 42 pilot, 155 main, stock needle #3. Ran decent. Noticed ALOT of spooge

3rd Ride: 38 pilot, 155 main, Stock needle #2. Lean off idle, wants to stall, rips mid to top. Some spooge

4th Ride: 40 pilot, 155 main, Stock needle #2. A little lean off idle, AS was set at 1 turn out. 

5th Ride: 42 pilot. 155 main. Stock Needle #2. Pretty much mimics the jetting chart, runs pretty well. Lots of spooge that I think is related to oil injection. Running Motul 710. 

 

IMG_20201022_171447210.jpg

Edited by ReaptheHeat

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23 hours ago, Primal Enduro said:

Last Thursday I rode the stock needle in the 3rd with 45/170.  Tomorrow I will try the same needle/clip with 48/168 per Kelsey and report back.  

 

tonight I rode with the above settings (stock needle in the 3rd and 48/168 which is one step richer on each than I was running with the stock head)  70 degrees and humid @1000'ASL  power felt pretty good in the short ride but not drastically different than stock head with stock jetting.  Went home and swapped in the NEDW with the same 48/168 combo. and as expected this needle took away a bit of the "hit" but felt a little lean in comparison to the stock needle, exhaust note was also mellow and somewhat quieter than stock needle.  

Next I'll try the N8RG needle when I can get to the dealer and pick it up.

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19 hours ago, whitemike said:

So does Kelsey tell you what jetting will work best once you put his head on?  What does he say about using a JD kit?

I don't think he likes the JD needles, or maybe he just has no experience with them.  The first post in this thread should answer your questions.

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tested 50p/168m today for an hour or so until my 7 year old EarthX took a dump. man i wish this bike came with a kicker, never used it on my 250 but needed one today ... knew it was gonna bite the bullet eventually but it's been fantastic throughout it's lifespan, never charged it, only remove and keep on bench for winters. anyway...

60 degrees F + muggy (wack fall weather), dropped gap on plug from 0.7mm to 0.5mm, stock needle, 3rd clip pos, 50p, 168m

super rich off idle, way too blubbery for me, turning the air screw out 2.5t helped but the ZipTy screw i'm running was ready to fall out around that range. also had to turn my idle way up from the previous setup. top end felt great wrung out, nice meat in the middle. tried a bunch of slow hill climbs a gear higher, had nice torque but i missed the strong snap off idle when burping along from down low and had a lot of 'over run' (?) which didn't sound or feel good ...  if i had some momentum going, the front end lofted real easy from the middle up but bottom was just mushy and sounded crappy. a benefit i did like was that decel was super smooth, that was different.

guess i'll try the 48p next while i wait for the KTM needle ... then i'll go back to the JD Blue in #4 w/ 40p, 175m and test that

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4 minutes ago, typeone said:

tested 50p/168m today for an hour or so until my 7 year old EarthX took a dump. man i wish this bike came with a kicker, never used it on my 250 but needed one today ... knew it was gonna bite the bullet eventually but it's been fantastic throughout it's lifespan, never charged it, only remove and keep on bench for winters. anyway...

60 degrees F + muggy (wack fall weather), dropped gap on plug from 0.7mm to 0.5mm, stock needle, 3rd clip pos, 50p, 168m

super rich off idle, way too blubbery for me, turning the air screw out 2.5t helped but the ZipTy screw i'm running was ready to fall out around that range. also had to turn my idle way up from the previous setup. top end felt great wrung out, nice meat in the middle. tried a bunch of slow hill climbs a gear higher, had nice torque but i missed the strong snap off idle when burping along from down low and had a lot of 'over run' (?) which didn't sound or feel good ...  if i had some momentum going, the front end lofted real easy from the middle up but bottom was just mushy and sounded crappy. a benefit i did like was that decel was super smooth, that was different.

guess i'll try the 48p next while i wait for the KTM needle ... then i'll go back to the JD Blue in #4 w/ 40p, 175m and test that

Those settings are pretty close to what I tried yesterday, I was just 1 size smaller on the pilot.  Like I said, it was just okay, and even with the suzuki NEDW it didn't feel as snappy as it did the previous ride with the same needle and 45/165.  So I had attributed that to the richer 48/168 pilot and main.  Then tonight I walk in the garage and notice I had the map switch in the rain mode...DOHHHH  

I'll go out and test again tomorrow before Sunday's full ride.

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