Curiosity about carburetion adjustment.

[Selvagem]

Hello.

I'm curious to know how you do to carburet their bikes. My current setting is perfect for large most situations, I can run fast, accelerate the engine to the maximum, shows no hesitation in standing idle while turning the acelardor fully., but when I face a high stress situation, such as being locked or need to push the bike up the hill, she ends up in these situations presenting the typical symptom, who is staying with the fast idle.

I have my perfectly adjusted carburetor from the level of float, which is in 18mm, I have no problem with the seal crank, everything perfect.

Personally, I think this is something normal. This weekend, I used a richer configuration needle and jet pilot, it ran well in tight spots, but with this set, I end up running out of idle, which I imagine using a rich set there is excess fuel in these circumstances, making it impossible to find a consistent idling, although that with this setting the bike did not show any symptom of being poor in the worst situations.

I do not know if other motorcycles happen the same thing with GasGas which to present a consistent idling, you need a perfect combination of needle and jet pilot. I realize that this confugura??o is perfect for almost any situation except for the mentioned above.

I would like to hear some opinions about it.

Sorry for my bad English.

This is the setup I like to use:

AS1 Carburetor
NECF #3
#48
#178
Screw air: 1,5V

Rich Setup:

NEDF#3
#50
#178
Screw air: 1- 1/4

 

[Zman]

If you can not fix the idle witt the idle mixture screw, then I would try going back ot the 48 pilot jet and then lower the needle clip one position to richen the midrange.

 

[Selvagem]

In this video, from 28:06 gives to get a sense of how the pro riders who participate in Hard Enduro evidence adjust the carburetion their bikes ... it's not for nothing that is rare visualize super bikes warming .... extremely rich carburetion, unfeasible for mere mortals ....

https://www.youtube.com/watch?v=4j6dyAMrPZU

 

[Jakobi]

Almost sounded like the float stuck open for a bit. Definite rich condition there, but did clear out eventually and then appeared to run like a champ (even in the tighter sections).

But on topic, there are definite compromises between the best power for heavy load applications vs putting around in the bush. Considering that these 2T carbs have no accelerator pump, any additional fuel required for heavy throttle transition needs to already be present (supplied by the pilot) which means you will have a certain amount of richness/burble during low loads.

 

[memphis2857]

That was caused by all the head pressure from the fuel can. There was more pressure than the float in the carb could overcome therefore forcing fuel straight down its throat. Happens a lot with those types of cans especially when the can is full.


Sent from my iPhone using Tapatalk

 

[Jakobi]

That was caused by all the head pressure from the fuel can. There was more pressure than the float in the carb could overcome therefore forcing fuel straight down its throat. Happens a lot with those types of cans especially when the can is full.

Makes perfect sense!

 

[Selvagem]

Thanks for the consideration.

One more question:

Assuming that already have a generous fit, with a jet pilot slightly larger than the ideal and yet the bike have minor symptoms characteristic in situations of great demands, it is necessary to try a needle with the richest straight part or is inevitable ? Their bikes, no changes to face situations like those seen in the video above in 19:50?

 

[julianorettore]

Selvagem the level of the float is 16mm according to the carburetor manufacturer's manual.I set my GG 2008 in this level, set in # 42, # 175, N1EG needle position 2 (up to down). note that the measures of the jets is well above the existing calculation in the manual because you're using a level of lower than recommended float. Therefore, thou mayest have problems idle when you're going down a hill or missing when climbing

 

[Selvagem]

I use jet pilot and main larger pilot because of needle use, very different from the OEM that you quoted.

18mm is the level of float that in most forums cites as the ideal, so that the fuel is not wasted in normal use....

 

[julianorettore]

http://www.gasgasrider.org/forum/attachment.php?attachmentid=5566&stc=1&d=1434058826
No manual da moto est? claramente q s?o 16mm com toler?ncia de 0,05. Eu mesmo tive problemas de nivel de b?ia em 1 mm de diferen?a e a diferen?a ? grande: sem marcha lenta, falta nas subidas, enfim, se o ajuste n?o for exato n?o funciona

 

[Selvagem]

His float level verification suggestion made me think of something that had gone unnoticed:

The angle that the carburetor is riding the bike.

Very Interesting:

http://www.thumpertalk.com/topic/899792-pwk-as-float-height-on-05-07-cr250/

In GasGas, the carburetor is very steep and this surely changes the fuel level in relation to a carburetor fixed on a more level plane.

 

[Jakobi]

Exactly why I have found adding another mm or two helps. The carb sits forward so far that when riding you get splashing and inconsistency with the stock float heights.

I don't think anyone has ran into issues running the bowl dry yet.

 

[julianorettore]

Selvagem , my GG 2008 has carburetor PWK Air Striker AS and I had to change the needle float. To re-adjust the level was complicated because the bike did not know enough. What happened was that left up to 1 mm above the recommended (17mm) she did not keep the slow or was in the slow and shut down in less than 10 seconds. Also I realized that there was a considerable slack in the pin float, pulled this off and improved fit. Since the carburetor is leaning forward causes the fuel downhill incline further and believe he pull air and the bike turn off intermittently. Obviously if you leave a lower level than recommended, more vacuum will be necessary to suck the mixture and if not enough it off. If you leave less than 16mm it leaks fuel with a breather. Another thing which is concludes that the slow adjustment of GG's too sensitive, 1/4 turn already causes her to be accelerated and after a while with the loose throttle it will reach the idle (+/- 1100 RPM ). If you adjust the level of float, already prepares some orifices that will be too rich with these measures that you are using.

PORTUGUESE:
Selvagem, a minha GG 2008 tem carburador PWK Air Striker AS e tive de trocar a agulha da boia. Para ajustar novamente o nivel foi complicado pois n?o conhecia a moto o suficiente. O que ocorria era que se deixasse ate 1 mm acima do recomendado (17mm) ela n?o mantinha a lenta ou ficava na lenta e desligava em menos de 10 segundos. Tambem percebi que havia uma folga consideravel no pino da boia , retirei tal folga e melhorou o ajuste. Como o carburador ? inclinado para frente faz com que em descidas o combustivel incline mais adiante e acredito que ele puxe ar e a moto desligue intermitentemente. Obviamente se tu deixar um nivel mais baixo que o recomendado, ser? necessario mais v?cuo para sugar a mistura e se n?o for o suficiente ela desliga. Se deixar menos de 16mm ela vaza combustivel pelo respiro. Outra coisa que conclui ? que o ajuste de lenta da GG ? sensivel demais, 1/4 de volta ja faz com que ela fique acelerada e depois de um tempo com o acelerador solto ela venha a atingir a marcha lenta (+/- 1100 RPM). Se voc? reajustar o nivel da boia, ja prepara alguns gicles que vai ficar rica demais com estas medidas que est?s usando.

 

[Selvagem]

According to many surveys conducted in various forums, the best compromise for the level float does not compromise the operation of the engine, preventing the tank from drying in critical situations and at the same time do not be too high, thus leaking fuel vents is by 18mm .

Image taken from a forum that I no longer have the record:

Noting the information leaving 1mm gap between the seams of the float, the measure resulting from the high part of the buoy and the carburetor is exactly 18mm.

I will try a different setting, with 16mm. Probably due to the inclined angle at which the carburettor is in GasGas, 18mm in some situations it is really inadequate.

Regarding your problems with idle for sure are due to needle using. I suffered for years with this problem and I know how much it troubled me.

I made a reasonable investment importing multiple needle models, and you know that in Brazil import is expensive time-consuming, which eventually resulted in a collection of needles.

 

[julianorettore]

Wild, it's great exchange ideas with those who have different experiences for your bike which type of needle that showed better results? I've been searching where is highly recommended to use JD Jetting needles. Used these type of needles? What are the improvements he felt on the bike?
I realize that the needle use the N1EG is too poor in the range of 30 ~ 40% of throttle opening where it fails even symptom of lack of fuel

PORTUGUESE
Selvagem, ? otimo trocar ideias com quem tem experiencias diversas, para sua moto qual o tipo de agulha que apresentou melhores resultados ? Estive pesquisando aonde ? altamente recomendado o uso de agulhas JD Jetting. Usou estes tipo de agulhas ? Quais as melhoras que sentiu na moto ?
Percebo que a agulha que uso a N1EG ? demasiadamente pobre na faixa dos 30~40% de abertura do acelerador aonde ela falha , mesmo sintoma de falta de combustivel

 

[Selvagem]

My problems were simpler than I thought .... I almost seven months without using my bike for several reasons .... when faced these symptoms was the 1st time I used my bike after this stopped time.

The fuel in Brazil is very bad, the government forces the mixture of almost 30% anhydrous alcohol in gasoline, that is one reason we use so rich adjustments relative to other parts of the world. In addition, there is the problem of adulterated fuel .... I decided to open the carburetor for a check and came across a lot of rust and pilot jet rather obstructed.

After a nice clean, went back to using my setup, NECF # 3, # 48 and # 178 all went back to work perfectly.

Now I need a suggestion:

There is another needle with characteristics similar to the NECF providing greater fuel economy?

My current autonomy is 75KM/80KM. When using NECH needle could 100KM, but lost much torque and the famous buaaa happened, to completely turn the throttle from idle.

Open suggestions.