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Burger72

Beta2Stroke RK Tech on a 200rr

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2 minutes ago, firffighter said:

Sounds like you are getting close.

I know it's tough to do, but ignoring the spooge and focusing on that feel of 1/8-1/4 openings and then the transition from 1/4 to mid is where the fine tuning is.

If you're confident in that needle fitting the chart shown for your elevation and temperatures,  then you can make the fine adjustments with clip position then AS to see if you can land on the sweet spot.  

Lean knock can be common on a head mod, but sometimes all it takes is a clip move or AS adjustment to slightly richen it up to remove it.  

Making large adjustments or going with huge changes can make it difficult to pinpoint the areas of fine tuning.  

 

So in my quick test ride on goat trail the power felt strong but linear and friendly.  Easily popping the front end up for pivot turns and such.  I've always had a good amount of spooge with this bike, just never that much in such a short distance...it doesn't really bother me, but maybe it's an indication of having to go a clip leaner?

I'm going to take it out for the full ride tomorrow and see how it does in various situations. 

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8 minutes ago, Primal Enduro said:

So in my quick test ride on goat trail the power felt strong but linear and friendly.  Easily popping the front end up for pivot turns and such.  I've always had a good amount of spooge with this bike, just never that much in such a short distance...it doesn't really bother me, but maybe it's an indication of having to go a clip leaner?

I'm going to take it out for the full ride tomorrow and see how it does in various situations. 

Hey man 

It might be coincidental, with temps lower after just a few miles your silencer won’t even be hot enough to burn the oil and if it’s always had plenty of spoodge then it will already be full up and waiting to piss out. 
Sounds like NECW same as mine would be near perfect, mine still blows a bit of spoodge after riding trails and not being on the pipe all the time but it rides mint 👍

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12 minutes ago, Primal Enduro said:

So in my quick test ride on goat trail the power felt strong but linear and friendly.  Easily popping the front end up for pivot turns and such.  I've always had a good amount of spooge with this bike, just never that much in such a short distance...it doesn't really bother me, but maybe it's an indication of having to go a clip leaner?

I'm going to take it out for the full ride tomorrow and see how it does in various situations. 

I don’t care about spooge. I go on how the bike runs. If it’s running good that’s all that matters. We aren’t riding mx etc. we are lugging low rpms in a bunch of places. Sounds good. Looking forward to your next report. 

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38 minutes ago, hawaiidirtrider said:

I don’t care about spooge. I go on how the bike runs. If it’s running good that’s all that matters. We aren’t riding mx etc. we are lugging low rpms in a bunch of places. Sounds good. Looking forward to your next report. 

no doubt!  I'm not worried about spooge, just an observation.  As Burger mentioned a 3 mile ride is not the best overall test.  That will come tomorrow.  I will report back after the ride.

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@Primal Enduro

Where are you experiencing the knock? Does it happen at all throttle openings? 

I'll just share my experience with that specific part of the equation.  Once I had the needle, pilot and main set that gave me the perfect linear smooth power delivery I desired, I had a lean knock that was happening sporadically.  It was consistent though  when coming off the throttle at 1/3 on up. The lower throttle openings I did not get the knock. 

So, since I had the power delivery characteristics I wanted I made really small changes to eliminate that knock. 

-I 1st moved the clip 1 position richer. This eliminated the lean knock, but resulted very slight richness that affected that linear throttle response that I wanted.  

-I played with adjusting the AS in 1/16 leaner increments until I had the rich condition gone.  

This resulted in accomplishing both lean knock being gone and linear power delivery throughout all throttle openings. 

On a side note.  This lean knock you're experiencing is not unique and there have been many threads on this with the RK Tek head on other brands and various cc 2-strokes. 

My brother has a Beta 250rr and has both an RK Tek head and a RB design head.  Since Ron is retired it's a moot point,  but the results are that the RB head was much easier to jet and find great linear power delivery.  But, the RK Tek head was significantly better in gains with low end pull, and cooler running engine.

My brother has struggled as well with finding a good compromise with jetting the RK head, but he's also a stubborn mule and won't use a Suzuki needle, Lol. 

Hope this helps and keep us posted on your progress.  This might be extremely helpful for me when I grab singletrack riders 200rr from him when's he's done with it! 

Edited by firffighter

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I’ve never had a spooge free ride on my 17” 250RR with the keihin or SC2 and a spark arrestor.  That said it’s generally only a couple inches down the pipe.  This was from last ride.  Almost all slower single track.  For me it’s all about how the bikes rides. So if it’s good and there is some spooge, no biggie. 
 

 

61DF06C1-5411-47B4-8F72-C30CD02586A9.jpeg

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6 minutes ago, firffighter said:

@Primal Enduro

Where are you experiencing the knock? Does it happen at all throttle openings? 

 

it was at idle after coming off the throttle when doing some bushwacking at a walking pace.  I think I got rid of it by richening the pilot circuit with the air screw.

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Just now, Primal Enduro said:

it was at idle after coming off the throttle when doing some bushwacking at a walking pace.  I think I got rid of it by richening the pilot circuit with the air screw.

Awesome, appreciate the feedback 

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Spooge means nothing with that long silencer.  You could saturate the packing enough over time that a really lean setting would eventually drool.  Cut 3 inches off and it makes more sense and is not any louder.

Burger is in UK, fuel is not a constant here. 

There is a certain overlap of pilot ckt and needle straight dia.   If the dia is wrong you attempt to compensate for it with the pilot and a/s.  Problem is your working with what you have, not with what you need.

Shouldn't be that hard.  In the end if it is, swap the head back.  Never had an RK head but every 2stroke had an RBD cut head.

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Just got back from full ride with the benefit of being able to swap back and fourth with a stock 2019 200rr.  Overall I had a good ride and am pleased with the way it was running.  when switching to the stock 200rr.  I did notice that it had a lot more "hit" than mine with the rk tek head and suzuki needle.  He mentioned my bike was more "responsive feeling"  I wouldn't say either had more torque or power but just a different delivery.  Not sure how much the head plays into this, or simply swaping the needle might yield the smoother feel?

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On 10/17/2020 at 1:42 PM, Primal Enduro said:

I'm heading out shortly to test the NEDW which as stated by Burger is only 1/2 clip richer, today's temp in NJ is about the same as his 12C/55F.  I'm taking the jd blue needle with me also so it will interesting to compare our results.

JD Blue #5 w/ 40p was a bit blubbery for me today. no knock, which was great, but i'm going to try #4 clip pos next to see if it cleans up a bit. i tweaked the air screw a few times but it still stayed kinda too fat burping along ... twist throttle climbing and smooth power though so we'll see

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On 10/18/2020 at 9:45 PM, typeone said:

JD Blue #5 w/ 40p was a bit blubbery for me today. no knock, which was great, but i'm going to try #4 clip pos next to see if it cleans up a bit. i tweaked the air screw a few times but it still stayed kinda too fat burping along ... twist throttle climbing and smooth power though so we'll see

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.  I then changed the pilot to a 45 and the bottom end felt much better.  Mid and top were the same as expected with just a pilot change.  Next I changed the main back to 165 and felt very little change in the mid/top compared to the 175 which is a pretty drastic change in size.  

I'm going to ride tomorrow with the NEDW 45/165 but have the feeling if I stay with the Suzuki needle I'm going to need the NECH, or DH.

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53 minutes ago, ktm450cl said:

@Primal Enduro i havent ready all 9 pages so appologies if this has been covered. Were you happy with the jetting before the rktek head? Are you messing with jetting now because things changed with the new head?

Yes and yes 

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58 minutes ago, Primal Enduro said:

Anyone try the N8RW or N2ZW (1/2 clip richer) with or without the head on the 200's yet?

The W will be too lean,... You should run the N8RG or H   The 45 pilot should also be lean.. I suspect you are fighting a pilot that is too small and that is why the needle is having such a pronounced effect. 1/2 clip changes only have big effects when you have the pilot or main sized incorrectly..

PLEASE install a 50 (at least a 48) pilot with a 168 main and N8RG (or stock) needle and see how it reacts . I think you will be surprised..  

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36 minutes ago, HERA said:

The W will be too lean,... You should run the N8RG or H   The 45 pilot should also be lean.. I suspect you are fighting a pilot that is too small and that is why the needle is having such a pronounced effect. 1/2 clip changes only have big effects when you have the pilot or main sized incorrectly..

PLEASE install a 50 (at least a 48) pilot with a 168 main and N8RG (or stock) needle and see how it reacts . I think you will be surprised..  

recently with the stock NE1I needle in the 3rd clip, I had tried 48/175 and everything was very "lethargic".

48 is the largest pilot I have at the moment

As far as richer straight section needles I have the following on hand:

NOZH
NOZG

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9 minutes ago, Primal Enduro said:

recently with the stock NE1I needle in the 3rd clip, I had tried 48/175 and everything was very "lethargic".

48 is the largest pilot I have at the moment

As far as richer straight section needles I have the following on hand:

NOZH
NOZG

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.

Remember, contrary to popular belief, the main jet does have a nice influence on all throttle openings.. The 175 is just too large and is effecting the rest of the circuits. Get the main down to a 168 and keep the pilot large (48 or 50) and reinstall the stock needle and things should get better.. 

Please try it

Edited by HERA

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3 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, just looked and I have 48p 168m and stock N1Ei needle to try next, Isn't the stock "i" diameter the same as the ''w" diameter @ 2.735?

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1 minute ago, Primal Enduro said:

okay, just looked and I have 48p 168m and stock N1Ei needle to try next, Isn't the stock "i" diameter the same as the ''w" diameter @ 2.735?

Great... that should work well..  I do not know on the diameter.  gap your plug to .020" as well and make sure you are using genuine Keihin Jets and genuine NGK plugs (very important)

What you will be looking for is very smooth low end tractability.. NOT quick revving engines.. but the ability to put the bike in a high gear and "tractor" around without having to downshift.

 

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