[2 stroke] Honda RS 125 rotary valve

A la chasse au Micowoy lol!

julien #41 a écrit:: Je parlais juste de calculer la section de passage dans le gicleur réglable correspondant à un gicleur donné qui fonctionne sur ce moteur pour avoir une base de réglage pour le premier démarrage. Le calcul est pas très compliqué.

Julien, can you show me your simple calculation of the available flow area in this real-life example, where the needle is not completely centered in the jet bore, which is usually the case, and with respect to the boundary layers of stagnating fluid inside the jet bore and around the needle?
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Frits I just talk about the adjustable jet of Micowoy where the needle (for the jet size adjustment) is centered in the hole for the setting of the gas flow, that is simple to calculate or design with 3D sotware.

I don't speak about the throttle valve needle wich is I agree very difficult to calculate according to the position of the needle and his radial free play.. [2 stroke] Honda RS 125 rotary valve - Page 4 980796

[2 stroke] Honda RS 125 rotary valve - Page 4 980796

julien #41 a écrit:: Frits I just talk about the adjustable jet of Micowoy where the needle is centered in the hole

So did I, Julien. You can only be sure that a needle is centered in a hole if there is zero diameter difference (which would be rather bad for fuel flow), or if there is a very long, tight guidance.
Often, when certain settings could not be repeated, the cause turned out to be a very slight tilting of the needle.
Without the boundary layers this tilting would not make any difference, but alas, reality is not so forgiving.

About the throttle valve needle: you may have noticed that in some carburetters the needle is spring-loaded laterally,
so it is always pushed against the same side in the needle holder, preventing the above-mentioned problem.
Another trick is a small O-ring tightly around the needle, between the needle clip and the slide body.
This prevents vibrations of the needle, that would otherwise noticeably influence the fuel flow.
These little details were the result of much head-scratching scratch

.

Il est toujours intéressant de prendre connaissance de plusieurs aspects du problème...

[2 stroke] Honda RS 125 rotary valve - Page 4 771973

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Un p'tit clik vaut mieux qu'une grande claque; c'est Harry qui l'a dit! [Vous devez être inscrit et connecté pour voir cette image]

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oui ,l'aiguille à du jeux dans le boiseau ,et celui ci dans le corps ...,après chaque démontage de cuve je dois la recentrer avec 1 axe centreur dans le gp mais il y a toujours 1 jeux mini pour le fonctionnement,c'est inévitable

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Nombre de messages : 351 Localisation : Belgique Date d'inscription : 05/12/2011

micowoy a écrit:: [Vous devez être inscrit et connecté pour voir ce lien]

ça, c'est de la musique [2 stroke] Honda RS 125 rotary valve - Page 4 101130

Frits Overmars a écrit:

julien #41 a écrit:: Frits I just talk about the adjustable jet of Micowoy where the needle is centered in the hole

So did I, Julien. You can only be sure that a needle is centered in a hole if there is zero diameter difference (which would be rather bad for fuel flow), or if there is a very long, tight guidance.
Often, when certain settings could not be repeated, the cause turned out to be a very slight tilting of the needle.
Without the boundary layers this tilting would not make any difference, but alas, reality is not so forgiving.

About the throttle valve needle: you may have noticed that in some carburetters the needle is spring-loaded laterally,
so it is always pushed against the same side in the needle holder, preventing the above-mentioned problem.
Another trick is a small O-ring tightly around the needle, between the needle clip and the slide body.
This prevents vibrations of the needle, that would otherwise noticeably influence the fuel flow.
These little details were the result of much head-scratching scratch

.

Frits, I really don't want to contradict or reinvent your works, at the started of the discussion I just said that it was possible to approximate (by calculate, modelisation or test like Micowoy as done) the setting of the adjustable jet to rich a known jet size to start the engine and begin the real setting.. [2 stroke] Honda RS 125 rotary valve - Page 4 980796

I always said that this first setting is "approximate", I know that an accurate setting depend of many parameters and the case of the throttle valve needle is another really interesting problem.

And finally many thanks Frits to share your knowledges here. [2 stroke] Honda RS 125 rotary valve - Page 4 771973

Je suis Fan micowoy, j'espère la voir de près le mois prochain [2 stroke] Honda RS 125 rotary valve - Page 4 809262

Je ne manquerai pas de venir voir ça de près [2 stroke] Honda RS 125 rotary valve - Page 4 980796

Toop a écrit:: Je suis Fan micowoy, j'espère la voir de près le mois prochain

Je ne manquerai pas de venir voir ça de près

Tu monte à Chimay , [2 stroke] Honda RS 125 rotary valve - Page 4 980796

On va même rouler ensemble Wink

Bonne nouvelle ,vous etes déjà inscrits ?
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Oui Etienne en ipc125 et moi en EVO [2 stroke] Honda RS 125 rotary valve - Page 4 980796

mickey a écrit:: A la chasse au Micowoy

Héhé, c'est moi ça ;-)

Bravo Michel pour cette naissance [2 stroke] Honda RS 125 rotary valve - Page 4 771973

» [GP125] All that you wanted to know on Aprilia RSA 125, and more, by Mr Jan Thiel and Mr Frits Overmars (PART 2) (Locked)
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