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SUPERTUNER ECP FILTER QUESTION

needle position

good day of testing for me raised needles 1 notch helped some with the hesitation,set all fuel screws to 2.25 turns,no difference,set needles to last notch hesitation gone,90 miles from railroad bed to slow going in the woods,no matter where i hit the throttle let off whatever was right there :D i especially like the sound ,doubles the effect of the armstretch,thanks again freddie,by the way you are know all over,all the veteran racers ive talked to know you by name ,sounds like you've been around keep up the good work,fresh snow tonight and tomorrow up to 12 inches expect b4 its over, finally,next thing to tackle is the tps,everylittle bit helps
 

I found zero difference moving my needles around with 165 jets ?? Running at -25c today about -10f and top end suffered today with 165, would not pull over 10,000 and seemed to go flat at 110mph on the speedo
 
top speed

i made several top end runs today 1/2 mile stretch of rr bed,hit 128-129 everytime,no loss of topspeed with 165 mains,2.25 turns on fuel screws,silver springs,stock tps setting,i thought temperature would affect it more but it didnt make a difference -10 or 20 today,needles made all the difference in hesitation,still will try to get carbs sync'ed just to be sure
 
I have zero hesitation from partial throttle to WOT at any speed, it only happens when throttle is fully closed on deceleration and they go to WOT. I am conviced it is simply the CV spring not allowing the slide to open quickly enough and is really a non issue as it only presents itself very infrequently !
 
hesitation

brx-1 i think your right ,i never had any higher speed bobble or hesitation just lower speed when you let completely out of the throttle and then back into it anytime below6000,above that was a non issue,i currently have fuel screws set at 2.25 turns out,any higher than that would be a bit much with the needles also in the highest position i would think but if anyone has set them higher with good results let me know thanks
 
I had a problem with my rx1 from the first day I got it.The hisitation when hitting bumps at high speeds was there all the time.Thinking it was the float bowls issue when it was the CV spring.Change to silver CV spring and it was gone.Put the stock CV spring back in and the hisitation was there again.With the silver CV springs my problem was slove. :D
 
Here's a reply I posted on the "mountain" side of the house. It almost sounds like I have the same thing going on as you guys. The below examples are from 6-8,000 feet. The sled ran great at WOT with the 156.3 main jets.

It's the midrange I had a tough time with though. With the needles one position richer than stock and the Holtzman silver springs this is at least what I thought I saw. On the trail cruising steadily between 8-9,000 rpm it seemed like there was a lean spot. I may have been more on the main jet but if I mashed the throttle it pulled like crazy and the lean bog or flat spot went away instantly. It only showed up if I loitered in this RPM range. It sure seemed like the upper midrange was lean. The fuel screws are at 1 1/4 (3-6,000 ft. mountain spec with air box) could this effect engine operation this high in the RPM band? Maybe a nozzle change is in order?

Then while boondocking up and over mountains with the same settings as above the sled seemed rich and seemed to load up in the midrange until I punched the throttle to clean out the blubbering. I imaging it's all about airflow into the carbs? At trail speeds there is way more air available to the engine and it actually leans out the mixture. Just the opposite could be true at slow boondocking speeds? Heck, I don't know but I'd sure like to find out why this is the case. Honestly, I'm convinced their must be a much better needle design that would compliment the use of these filters. PB
 
Hum?? Maybe. I did notice the same TYPE of thing when we were getting close to Stanley Idaho and there was a bunch of ice fog hanging in the air. Turning on the carb heat cleaned most of the problem. PB
 


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