Carburator delay when adjusting mixture of 2-cycle engine

[levittownnick]

It appears that when adjusting the idle mixture of 2-cycle engines there is a long delay (possibly in the order of 30-seconds to 1 minute) in the time from when an incremental adjustment is made to when the engine responds. This delay is not apparent in 4-cycle engines. I would love to understand how this delay is possible. I'm hung up with the fact that over a period of 30 seconds at 800 rpm, the intake through the crankcase happened 400 times. What Gives?
Thank you,
Nick

 

[jakedaawg]

Just the way it is...but it is interesting. I think the longer delays are on the ones with the most carbs...tuning the old v8 Johnson's was fun. .unless we had the fuely manifold on...when I tune a single carb two cylinder the change is more noticeable.

Your also comparing Apple's to oranges in a sense with the 2 to 4 comparison. In one case we are adjust rich vs lean and in the other we are balancing manifold vacuum to do essentially the same result but different in a sense. This would be on the big multi carb units .

 

[jakedaawg]

There is also a lot of residual mixture I a 2 stroke case and it takes time to fully get to the new mixture where as a four stroke the intake manifold is less volume so less time to get new mixture.

 

[jimmbo]

Cause in a four stroke you are not using the crankcase as part of the induction system

 

[levittownnick]

The engine that I am referring to is a '97, 150 Johnson that has 6 carburetors, so you are right on with your analysis. I have zero knowledge about balancing manifold vacuum, can you talk about that?

Thank you,
Nick

 

[jakedaawg]

The engine that I am referring to is a '97, 150 Johnson that has 6 carburetors, so you are right on with your analysis. I have zero knowledge about balancing manifold vacuum, can you talk about that?

Thank you,
Nick

It's a four stroke thing...special vacuum tools and what not. Not done much anymore, everything is injected now.

You just need to turn a screw and wait, turn the next one and wait...over and over and over....till it's perfect.

Hope your somewhere warm

 

[82rude]

Didn't they use mercury filled tubes at one time?Idea was to adjust all tubes to the same value?If I remember thats how they adjusted my 3 2 throat carbs on my kz1300 six banger. I ever wanted a vehicle back its that beast.

 

[jakedaawg]

Didn't they use mercury filled tubes at one time?Idea was to adjust all tubes to the same value?If I remember thats how they adjusted my 3 2 throat carbs on my kz1300 six banger. I ever wanted a vehicle back its that beast.

Can you believe the screams from the enviromentalists if they let mercury back into things...and on the water no less...shame on me for even thinking it.

 

[levittownnick]

It's a mystery and I guess it's going to stay that way. The saying is "Curiosity killed the Cat ...: I'm glad that I'm not a cat. lol.:lol:

Best reards,
Nick

 

[rbh]

Didn't they use mercury filled tubes at one time?Idea was to adjust all tubes to the same value?If I remember thats how they adjusted my 3 2 throat carbs on my kz1300 six banger. I ever wanted a vehicle back its that beast.

Were they not called carb sticks? and plumbed into the choke plunger holes so you would get the preasure from each carb balanced by watching the mercury rise while you did each adjustment?