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slide change
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Posted by: Porter---------------------

What effect will a #7 slide have in place of the stock #5 slide?How will it affect the rideablity?Looking for some advice from someone who runs a stock 200 carb with a cel,cek or bel needle.Is it easy to modify a #5 or better to buy a new #7 slide?Current config is a stock head,K35 pipe,DF2,cel4,35p&152m.

Posted by: canyncarvr---------------------

re: is it easy

Sure. If you know how to do it. Everything is.

I wouldn't attempt it.

Ron (of RB carb mod notoriety) will machine your slide for $15. You wanna mess around with a grinder for how long for that price?

You can just BUY a slide from him for around $40. Buy whatever cutaway you want. Then you can experiment between the two of them.

Ron can be contacted HERE.

Do some reading HERE! to get some excellent input on slide cutaways and what they do. That the thread is headed 'rb carb..' isn't of consequence. There's good information in there related to your question...like (from jd):

Quote:

Different slides are going to make the needle straight diameter difficult to select for a broad recommendation. A #5 slide may work best with a 2.705mm straight diameter where #6 needs 2.695 and #7 needs 2.685 and a richer clip position to get the close to the same jetting.

Seeing as you're running a 2.705 with a #5..and that being rather unusual for someone that hasn't been paying attention..you likely have already BEEN on this thread. Congratulations!

Do you have a hi-rev problem on choke-cold start with your 35p?

Posted by: Porter---------------------

Ya.I've been on that thread before.First time I've actually read it.Thanks for sending me back.The 35 pilot has not gone wild during cold starts,but it's only been in for a handful of hot days.I've gone through that with a 38 & a 40 on colder days( below 68*)So,can you show me a picture(of the #7) so I can get it right?Sounds like I can run a BEL or CEK to suit my mood as long as I'm using a #7.But will the CEL work well with the #7? Also,I read an article about "proper plug gap".It made reference to a gap set according to cc size.Have you read it & what do you gap your plug at?Going riding on Thurs. on some tight trails with only a couple open runs(70* forecast).I'm running a BEL2/38/150 with my #5 slide.I'm really in love with the CEL but when I changed jets I noticed it was worn.I'll post my thoughts about the ride in this thread.Thanks again for your help.

Posted by: Jim Crenca---------------------

I'm in the middle of changing slides in an RB modified carb (thanks to advice from evil friend Canyon Carver); what year is your bike; Ron is doing research as 94 carbs are different than new and slide / needle relationship appears to be different. Dan (Acutemp) and Ron are sorting this out currently for me as I have this crazy idea to get in the middle screwing up a properly jetted motorcycle

Posted by: Porter---------------------

It's a 2001 with a stock motor.The 35mm is hooked on a DF2 and the inside of the carb has been buffed smooth with a dremel tool.

Posted by: Porter---------------------

The ride today was great.I was real happy with the carb setup.35mm#5BEL2/38p/150m-1.25as/VForce2 reeds set on high tension.K-35.Temp was 72*,running between 500ft-2000ft.The motor did everything I asked it to,right when I needed it.From low speed snot to top speed it was all there.On two open stretches it ran thru all the gears fast and smooth.The motor had revs that seemed endless right up to 65.That's the fastest my 13/50 combo has seen.One open stretch was full thottle shifting and the other was rolling the throttle thru the gears.Both had the same result.Did I say I was in love with the CEL?Jetting now falls into the obsession catagory.I thought with this needle that the ride might be a less than exciting. Not so.The front wheel was in the air alot(controllable lofting)and the thottle response was great for clearing things on short notice. I know now I have to buy a #7slide.

Posted by: Jim Crenca---------------------

My advice?

Send it to Ron for even more happiness & consider a CEK if you like motocross like response.

Posted by: canyncarvr---------------------

re: gap according to cc
I haven't seen it. Don't see the reasoning to it. I gap mine a bit on the wide side (.030"), something the bike has no problem handling with proper jetting and (sez me) the better spark with the electrex coil. I've been running a narrow electrode (-EG) plug with excellent results.

I haven't tried a CEL in awhile. I started rich and went lean, and the CEK has a perfect (not kinda ok, not reasonable, but perfect) bottom end. The bike doesn't 4-stroke off any sort of long downhill...twist the throttle and the engine is back on n-o-w! Also, the bike takes a bit long to get to that perfect spot from a choke cold start. It's gotta reach temp before it's good to go. I can tell it's on the verge of being lean already (#7 slide. I've tried a #6 with the CEK..didn't like it), so a larger straight diameter (CEL) isn't called for.

I used to run a BEL when I wanted to tone things down some. With the change of the DFII reeds to 'lo' and the -30 pipe, I haven't done that for awhile. Now it's a change from clip-4 to -3 on the CEK when I want a bit less 'handful-o-bike'.

Also, the AS is perfectly tuneable for given temp changes I ride through during the day. Another sign that the bike is 'just right'.

re: Jetting now falls into the obsession catagory

Isn't it something? The riders that aren't willing to invest the time and effort or make any headway in understanding how jetting works are so far behind the 8-ball..... When you hit that 'sweet spot', you sure-as-hell know it, 'eh?

Dang!! It's good to read a post from a rider that appreciates what can happen with decent tuning.

Jim: Hope you keep this up-to-date with what you find out on the '94. Ron and dan are good folk! They are hugely responsible for raising the fun-factor on the kdx a good bit! My hat's off to the both of 'em!

Thanks

Posted by: farmerj---------------------

To you guys with the RB carb mod - Can us guys with the stock carb follow the same jetting/slide recommendations? Doesn't the divider plate and larger bore make the jetting respond differently than stock?

To Porter - Re: the "hi tension setting" on the DF2 & the CEL needle - I'm surmising that you like the more mx-style "hit" - but why then a torque pipe? Have you tried the "low" tension setting on the DF2, and if so - what did you think?

(BTW - These sound like great mods. I'm planning to do them, but want to get real familiar with what stock "can be" first.)

Posted by: fishhead---------------------

The cek-3 with#6, cel-3with #5 and cej-3 with #7 will be close enough to get you in the ball park with the stock 200 carb. The cej will probably like a lean pilot if you spend much time on downhill technical sections. My favorite was a cej-3 with a #7 and lean pilot. 35-40

I do have a couple of slightly used slides in my box #5 and #6. For the sake of science and expanding the jetting knowledge base I'll let them go quite reasonably. If you currently have a #7 you'll be set for some serious tuning. pm if you have interest.

Posted by: Porter---------------------

To:Farmerj-When I ran the reeds on the low tension setting,with the only pipe I have(k-35),I had very little top end.The motor seem to be buzzing real bad with a definate wall at the end of the power curve.Now that I have tried it on the high tension setting, I'll never go back.Unless I have a K-30 or somehing like it.I've always had the bottom I wanted.Now I have some top to go with it.One thing I've learned from reading this forum is that all of our bikes are slightly different in some way.Of coarse,we as riders,are different.A hard hit to me may be not much for you.A motor thats been taken apart and put back together buy two different people will probably run slightly different.Using others ideas for a baseline set-up is good.It definately helps you get going.Finding you own baseline is the key.Once you get that,adjustments for any given ride is alot easier.

Posted by: fishhead---------------------

Good point!

There is a certain amount of setup knowledge that is universal and a certain amount that is tribal knowledge that applies to your specific application.

That is one reason why I practice thorough testing and keeping good notes. I did a test run the other day and temps were unusually warm and humid for this area and time of year. The bike was a lot richer than I expected and it helped me to appreciate some of the difficulties people face when trying to help others with setup or trying to use others info for setup. I spoke to several others on Sat who had noticed the same thing. Some had revised their setting to accomodate the unusual conditions and others had recognized the richness was the result of humidity and compensated accordingly.

Posted by: farmerj---------------------

Thanks for your response, Porter. I have both pipes, so your comments will give me something to think about as I try out the options. I went back and reviewed some old DF II threads, which left me inconclusive (is that a word? - how about "unconclused"??!) regarding which pipe people were using. It may be that the big DF II gains on "low tension" are with the KG-30/rev, while the torque pipe likes "hi"...

Posted by: canyncarvr---------------------

Thanks for the input, fishhead.

re: 'unconclused' ?

I like that!

I did use my -35 with the DFII reed tension set to 'hi'. I didn't notice much difference on the top end of things over the radvalve. Note that is where the radvalve is working its best considering its 45º construction and carbon reeds. My opinion (and proven to my satisfaction anyway) is no intake reed system is going to 'overcome' the tune of the exhaust system on its own limiting end.

But the -30 doesn't 'limit' the bottom end, it just isn't tuned to 'work' there.

An argument that the -35 doesn't limit the topend, it just isn't 'tuned' to 'work' there......is not an apples-to-apples argument.

Thus, I arriveth at the current state of affairs, a -30 with DFII reeds set to 'lo'.

There are two exceptional points made above:

1. (Porter) One thing I've learned from reading this forum is that all of our bikes are slightly different in some way.Of coarse,we as riders,are different.

2. (fishhead) ... temps were unusually warm and humid for this area and time of year. The bike was a lot richer than I expected and it helped me to appreciate some of the difficulties people face when trying to help others with setup or trying to use others info for setup.

Amen!

The general tendancy of 2-strokers seems to be intimidated, skeered or just plain not interested in the 'hassle' of jetting.

That is certainly their loss.

You just can't jet your bike like someone else's and expect it to be correct. There is only one choice, and that is to do it yourself.

I've glossed over a good lot of the detail that is associated with proper jetting. I don't want to scare anyone off from getting started on their own knowledge base of jet-sets by painting too fine a detail. There is not a strong liklihood that you can ride a woods bike in its natural environment for even a single day without some jetting adjustment if you want to keep on the cusp of performance.

Around here, you can easily ride thru a 40º temperature differential and 4000' el. change on one ride! That's not something you'll find in an mx-track race.

BTW, don't take that to mean I worry about that cusp all the time....or even a lot for that matter. I know when the bike is right, when it's not...and probably have a pretty good idea as to the whys and wherefores of its attitude of the moment. It's much more fun when it's right on, but I'm not going to stop by the side of the trail 3-4 times during the day to 'fix' it.

I might tune the day before for what I expect....but that's about it.

I'm looking forward to famerj's pov of the -30/35 hi/lo setups. His conclusions may well differ from mine (see #1 above), but I hope to hear about it anyway.

Posted by: acutemp---------------------

Porter,
While I do prefer a leaner slide than the stock #5, before you change slides I would try a couple of different needles. The BEM works well with the k-35 pipe and the stock slide. A CEM would be worth a try also if you like the hit of the C taper needle but in most cases that I've seen the B taper is a better choice with the k-35 pipe. That said, every bike and setup is a bit different and only through testing can you find what's best for YOUR bike.--Dan

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