Yeh definitely, I will try playing with its adjustment when I next start the bike.
In the meantime, I've been reading up on how carbs work - these have been a great source of information:
carbkitsource.com/carbs/tech/articles/Tu...buretorTuneUp01.html - Too bad its missing the section on High Speed and power systems
and a 1980's Cycle World article called "In search of a Free Lunch" -
www.mediafire.com/?7ttgomzmmjz
So I'm going to just think through what I understand, as there are some things which don't quiet make sense to me yet. Bear with me.
1. Carburetors operate on the difference in air pressure, with the low pressure spaces forming vacuums which suck at high pressure spaces.
2. Initially, the low air pressure formed in the carb throat/bore is caused by the intake of the engine, or the downward motion of the piston.
3. This low pressure affects the fuel in the float bowl and draws it through jets, starting the whole process.
4. This also relies on the Venturi Principle, which states that when an air passage narrows, moving air flows faster, making it an even lower pressure...
Now, in the context of jetting and pods:
1. Pods provides less restriction than stock air boxes, and more air gets to the carb bore. (More air does not equal lower pressure does it? So I am thinking that the issue why more air enters the carb is because there is more surface area for it to enter from, thus when the butterfly valve opens (controlled by the throttle) then more air is coming in...ok that seems to make sense.)
2. So then, shouldn't more air create a higher atmospheric pressure than before? Or is the low pressure even greater? I think what I'm asking is, does the engine suck in air at a greater rate because there is more air, or if the rate that air is sucked by the downward movement of the piston remains unchanged, which in my mind, means you will now have a higher low pressure than if you had an airbox, as there is now extra air?
3. Leaving that confusion alone:
lean - not enough fuel, too much air
rich - too much fuel, not enough air
It sounds like the mix of air and fuel occurs in the same volume - in the jet passages? so more air = a more air and hence less fuel. This is why carbs usually run lean. Hence jets have to be increased to allow more fuel to pass through. The aim of jetting therefore, would be to try to replicate the fuel/air ratio obtained when running the stock air box, at the different systems.
4. Therefore, if I'm running rich - I need to use smaller jets to decrease fuel flow. If it is the pilot system, I will also screw out the pilot screw.
5. If I'm running lean - I will need to use bigger jets to increase fuel flow. With the pilot system, I will be screwing in the pilot screw to also decrease air.
Symptoms of a rich running carb:
- boggy/sluggish acceleration
- black spark plugs
Symptoms of lean running carb:
- backfires when throttle is closing
- white/powdery plugs
- requires excessive choke to start
So at the end of all this, I am slightly confused because:
1. My spark plug shows I'm running rich.
2. My bike does not run without the choke on - it will stall
I'm thinking perhaps I'm not getting full power to my coils perhaps? That would explain the plugs.
The combination I'm running of the 130 main and 70 secondary seems to have worked for others on this site, so I'm not sure - I understand that jetting is particular to bikes and its not a one size fits all thing.
So, any advice would be great - and definitely let me know of errors in my thought process.