3 needle carb questions????

[woody]

Hey Guys,
I just got my 777, and I'm presently breaking in the Engine. The kit cam with the Sirio Kanai Evo II, and its a 3 needle carb. Now I've been in the hobby for a little over a year and can tune engines (2 needle) pretty good. But, this is my first 3 needle carb. When I got the engine, I inspected and flushed it out. Reassembled it, and got it cranked the first time really easy. I know where the low, mid, and high speed needle is! I'm using 20%, good fresh fuel, maybe a month old. Glow plug charged, etc... The factory settings, I think were really off. So, I went to Trinity's website and it said:

Sirio .21 (General Carb Settings)
Low End: 2-1/2 turns out
High End: 5-1/2 turns out
Midrange: Flush then ½ turn out

Does low end 2 1/2 turns out mean from fully closed? Also the same for High end, does it mean 5 1/2 turns out from fully closed?? If so, they were way off.

My biggest problem it seems, is that the idle is like really high! Once it warms up a little it will settle down, but not like it should. You know after running, you bring it in and your engine will wind down a little. Well, mine won't do that! Also, when I give it gas anywhere throughout the power band it seems to want to die out, or try to. Especially in the middle. I have set the carb settings to what it says up top, and I really can't get it to run worth poop. Most people say to never touch the mid speed needle, is this true?? Anybody with a Sirio .21 3 speed needle, what are your normal settings for just everyday running? Any help would be appreciated! Thanks!!

 

[Rolex]

Read this link......pretty much the same question as yours. And yes, the settings are from fully closed.

https://www.rcnitrotalk.com/forum/showthread.php?t=21882

 

[woody]

Thanks Rolex, but that did'nt answer my question. I have a three needle carb, not a two needle which you referenced in the other post. I have three needles, and them the idle screw. I've got the idle screw adjusted properly, but the Low speed needle, and mid speed needle are what I need help on. Anybody out there with a Sirio .21??

Woody

 

[WsW-WYATT-EARP]

most of the articles i have read and threads i have read concerning a 3 needle carb ... say that it stays stock 99% of the time ... it is a needle that can really mess your tuning up ... and that unless you really know what you are doing with it you won't better your tune ... most people just leave it stock and tune the 2 needles (high and low) ... also that it is there to help smooth out the transition between the high and low needles ... and unless you run everyday you won't notice a difference ...

here is an article i found on a different board ... you will need to register to see it ... but it is well worth reading ...

needle balance article

 

[Diver6127]

Don't touch that third needle. It's basically a spray needle. It adjusts the atomization of your fuel. Mess it up and you'll have your hands full for a while.

 

[Rolex]

Sorry, I misunderstood. On a 3 needle carb, you DO NOT mess with the middle setting. Only the LSN, the HSN and the idle screw.

 

[woody]

Thanks WSW Wyatt Earp!!! That was a great article! So, in turn I learned that you really should'nt mess with the MSN (mid speed needle) at all. You should just tune the LSN and HSN! Let me put the needles back to what Trinity's website says, and then I'll tune the LSN from there. After I got it all worked out, I start with the HSN. Just like a 2 needle carb. Don't sweat it Rolex, I appreciate the help. I'm seriously considering getting the Sirio 2 needle carb for it. But, at $100 I think they can have it for right now!! Talk at you guys later, and I'll tell you how things are coming along!!

Woody

 

[Robie6]

the "third needle" is actually not a needle at all but is the adjustment for the LSNV SEAT. Listen up hear cause there's no magic & if someone tells ya "dont touch it" & your a human being your gonna touch it cause they said not to. I did.
My Dirt Demon has a 3 needle carb so I bought a book that tells all about them with pictures & alot less confusing then I can but the bottom line for the adj. is for racers to "tune in the mid-range at the track. It shouldn't even be on a carb that sells to us normal guys cause its a pain in the wazoo till ya understand. It has to do with the air-flo over the LSNV "SEAT" as the engine is running & the position of the barrel over the SEAT. Seems some rocket sientist figured he could get more air-flo over the seat at an earlier rpm range if it didn't stick out in the bore so far & the barrel was passed it earlier in the rpm range. This causes a tad more vacume over the seat at an earlier time & it works but but is so non signifficant in our world its just a pain. What most don't say is if you move the SEAT you have to move the needle the same amount or the whole adj. will be out. The best way for me to try to help ya is put the "SEAT" or third needle (as is called) just sticking into the bore of the carb (WHEN LOOKING INTO THE BORE) about 1/3 ways as ya screw it in. This should allow the barrel to be completely past the SEAT a little before 1/2 throtle. Dont get the word barrel mixed up with needle. When the barrel is past the LSNV seat there may still be part of the LSNV in the seat. If I try to explain any more I'll really confuse ya so If ya dont get it let me know & I'll drag out the book & edit it here, or email me & I'll copy the article for ya & send it out robie6