Setting up the CVK - Can old dogs learn new tricks?
#11
I did a search for some video's of a cv in action under load to try and get a better idea of how the slide reacts under load. Found this one-watch around 3:30 and 5:30 to see how long it takes for the slide to go WFO.
This may make it a bit easier to see why it's more challenging to understand what circuit is actually working based on throttle and rpm.
#13
For those of us that think we know what we are doing and that our opinions should have merit.
My dyno testing and resulting AFR charts has proven that this article needs to be memorized. While I will not test the way the article describes – because I have a dyno shop around the corner – this knowledge should be CVK "101" for every one of our members - especially us loud "old dogs" that think we know..
Edit: This is CV performance tuning - Not CV problem troubleshooting. If your bike runs perfectly well, this article could unlock potential. If your bike is not running correctly, you need troubleshooting.
CV Carb Tuning Procedures
My dyno testing and resulting AFR charts has proven that this article needs to be memorized. While I will not test the way the article describes – because I have a dyno shop around the corner – this knowledge should be CVK "101" for every one of our members - especially us loud "old dogs" that think we know..
Edit: This is CV performance tuning - Not CV problem troubleshooting. If your bike runs perfectly well, this article could unlock potential. If your bike is not running correctly, you need troubleshooting.
CV Carb Tuning Procedures
Factory pro settings at sea level 2010 KLX250S 122 main, (since changed to 120 and just right) , 38 pilot metering rod on 2nd clip (still going to adjust the rod slight flat spot between 3500-5000rpm. (Most wouldn't feel it but unfortunately I'm a little **** about things like that). Screw 21/2 turns, with snorkel installed, stock air filter and FMF Q4 slip on.
Can't say enough good about factory Pro kits. Will never use anything else.
I don't know how you guys ride with no air box cover. I removed the snorkel and couldn't stand the noise and replaced it after one short ride. The pipe isn't so bad as it is behind the rider not under you ***.
Last edited by Cota; 01-28-2015 at 07:13 AM.
#14
GBAUTO, Oustanding video ! I'm with TNC - It's crazy how slowly the slide responds to WOT input. Can you imagine the effects of a faulty/damaged diaphragm ? The lighter spring in the DJ kit probably does a lot more than I thought for overall responsiveness..
Obviously all circuits and systems have to be properly set up but it seems a lean idle and pilot system would really kill the responsiveness of the slide to WOT snaps..
Obviously all circuits and systems have to be properly set up but it seems a lean idle and pilot system would really kill the responsiveness of the slide to WOT snaps..
Last edited by Klxster; 01-22-2015 at 09:00 PM.
#15
Just finished a test run - DJ 136, needle at 5N, fuel screw out 3.5 turns.. It's about 49F out here.. Bike runs flawlessly and has more power hitting sooner than before.
#16
On the carb topic, but off the CV a bit -
Seems there was/is a TM34-2 kit made by White Bros. for the DR350 Suzuki. I found a TM36-2 supposedly set up for a DR350 and am giving some serious thought to it. One DR350 rider in the Thumper Page forum said this:
Seems there was/is a TM34-2 kit made by White Bros. for the DR350 Suzuki. I found a TM36-2 supposedly set up for a DR350 and am giving some serious thought to it. One DR350 rider in the Thumper Page forum said this:
I have a TM34 that was on a DR350, the jetting is
30 pilot
170 main
6DH2 Needle
with I think an 'O' nozzle.
I never could get rid of the bog at low rpms's when I whacked open the throttle. If you rolled the throttle it was fine.
If you ignored the bogging at low rpm's the bike ran better with the TM 34 than it ever did with either the CV or TM33 (currently installed) It made more power, lifting the front wheel was easier. Also with the TM34 it was much easier to start, a light half hearted kick was all it ever needed to start the bike.
Overall the TM33SS is better, less headaches and more info availible.
Having ridden SR500s one with a VM38 and one with the stock non pumper I know what they're talking about. You do not just crack the throttle from idle or extremely rpm, they will gulp and bog or stall. That jetting listed was the set up from WB, the question would be if the pilot jet/screw were right for the set up, would it do better with a size bigger? Would it help if the needle went one notch richer? No discussion found yet on that. Clearly if you can keep the Rs up a bit the non-pumper can be a viable alternative per WB thinking. I've wondered about that from my first reading about the TM36-68, knowing about the SR kits and others.
30 pilot
170 main
6DH2 Needle
with I think an 'O' nozzle.
I never could get rid of the bog at low rpms's when I whacked open the throttle. If you rolled the throttle it was fine.
If you ignored the bogging at low rpm's the bike ran better with the TM 34 than it ever did with either the CV or TM33 (currently installed) It made more power, lifting the front wheel was easier. Also with the TM34 it was much easier to start, a light half hearted kick was all it ever needed to start the bike.
Overall the TM33SS is better, less headaches and more info availible.
#18
Actually, you will never get the CV under control - the vacuum does that!
Really, one of the reasons I would like to do the non-AP carb is to avoid dealing with the pump timing, etc. The slide carb alone is pretty much the same as the CV - pilot/needle/main - for the most part. It might have a needle jet that can be changed out, but highly unlikely needed if using the DR350 WB carb settings, and the slide cutaway might be an issue, but not much and again not likely needed if using the WB set up. I was really looking for something to give ball park jetting stuff and that's it.
Really, one of the reasons I would like to do the non-AP carb is to avoid dealing with the pump timing, etc. The slide carb alone is pretty much the same as the CV - pilot/needle/main - for the most part. It might have a needle jet that can be changed out, but highly unlikely needed if using the DR350 WB carb settings, and the slide cutaway might be an issue, but not much and again not likely needed if using the WB set up. I was really looking for something to give ball park jetting stuff and that's it.
#19
I am getting Dyno runs today - one with the full FMF system(megaboop + PC4) and one with the DG-R + stock header.
The DJ136 + 5N + 3.5 turns out on the fuel screw + lid off .. Makes the bike exciting.. Even for an old "Open Class" rider like me.. I would include the MCM except that more than a few aren't running with MCM and report great results and happiness with 132/4n and lid off.... Since the 132/4n is still lean near sea level and can produce a "hiccup" every now and then when snapping to WOT from lower RPM, members up to 2-3k(and a perfectly good running DJ kit) should try 132/5n and 3.5 out on the fuel screw IMO.
The DJ136 + 5N + 3.5 turns out on the fuel screw + lid off .. Makes the bike exciting.. Even for an old "Open Class" rider like me.. I would include the MCM except that more than a few aren't running with MCM and report great results and happiness with 132/4n and lid off.... Since the 132/4n is still lean near sea level and can produce a "hiccup" every now and then when snapping to WOT from lower RPM, members up to 2-3k(and a perfectly good running DJ kit) should try 132/5n and 3.5 out on the fuel screw IMO.
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08-30-2008 04:47 PM