[jopro]

Hi all,

Related to my previous topics, see post: "running with choke open novice tuner!! HELP please"

I have reduced the size of the pilot Jet to 30.. it seems to work better at idle ..

I still get the same problem that when I open the gaz the bike won't accelerate unless I have the choke level pulled.
unless I have the choke level pulled: the bike has a very big deep: a big BOOOWWwww! with no power what soever when accelerate..

I am decided .. and think that I will do some trial with a smaller main jet: my current Jet is a 200 and I have an intuition that it might be the cause of all my problems.

1) can the jet cause to have a total loss of power?... is it that critical?

2) by reducing the jet size what would you recommend to start from? what intervals would you guys try first..

Let countinue on ridding..!!
Jopro

PS: forgot to add: I have a 500cc. with a sport silencer. and an boyer digital electronics ignition. Let me know if you have any question about the configuration of the bike.

 

[Thumper]

Jopro,

For background, you might review this:

http://www.enfieldmotorcycles.com/forum/index.php/topic,190.msg1069.html#msg1069

- When you remove the air filter and look into the carb throat you should see the slide valve and the choke mechanism (as you engage it and disengage it). When you "have the choke level pulled" and the bike is able to run, do you see the choke mechanism visible in the carb throat? - Or, is it lifted up out of the way and not visible?

Matt

[jopro]

Hi Thumper,

I have a Velocity Stack air filter.. When I engage the choke level, there is a rectangular slide (called the air valve, apparently) which is situated inside the throttle slide, which lift upward and become none visible.

do you think it means that the choke is actually off? cause I had the feeling that lifting this bar inside the the throttle slide was increasing the volume of the air chamber and therefore having an effect on the mix... effect which I obviously do not understand, I must make this clear.
How am I looking for something to far there?

thanks for the link.. and for your help
 

[Thumper]

Hi Thumper,

I have a Velocity Stack air filter.. When I engage the choke level, there is a rectangular slide (called the air valve, apparently) which is situated inside the throttle slide, which lift upward and become none visible.

do you think it means that the choke is actually off? cause I had the feeling that lifting this bar inside the the throttle slide was increasing the volume of the air chamber and therefore having an effect on the mix... effect which I obviously do not understand, I must make this clear.
How am I looking for something to far there?

thanks for the link.. and for your help
 

jopro,

You are correct then: when the choke mechanism is lifted up and out of the way then it is not having any effect. You are correct that when it is lowered and blocking the throat then it causes less air to come through, thus enrichening the mixture.

Back to your original question: Yes, if the main jet is too large (waaaaay too large) it can cause the bike to bog down. (Even with my bike running great, I can detect a richer mixture at the upper RPMs as compared to when I have it running leaner). It is hard to tell if that is your problem. There are a couple of things you can do to methodically trace it down: first is to determine precisely where the problem is - and where it is not. Eliminate the choke from the equation altogether. Use the 4 circuit method and find out which circuit is affected. If it won't run smoothly at or near full open throttle, then it is your main jet after all. If its when you transition off of idle then it is likely the slide valve cutaway. After that it could be the needle. You might also post to the Hitchcock's forum since they have a lot of Amal experience and someone might be able to immediately recommend a main jet size.

Matt