four stroke carb adjustments

[overbore]

Anyone have a explanation or a link on all
the circuits or adjustments for a four stroke carb?
Whats the purpose of accelerater pump?Is there a
idle fuel and air adjustment?primary,ect.
Thanks for helping me understand the big picture.
I understand the two stroke carb and how the circuits
tie together on the graphs,but not sure on four stroke.
overbore

 

[Ol'89r]

Whats the purpose of accelerater pump?Is there a
idle fuel and air adjustment?primary,ect.

Other than the size of the jets, a four stroke carb is much the same as a two stroke carb. The jet sizes are smaller in a 4-stroke carb since a 4-stroke is drawing fuel on every fourth stroke instead of every second stroke.

The accelerator pump is a minature fuel pump that squirts a little fuel into the intake when you first crack the throttle open. Gives better throttle response.

Just my $ .02 :thumb:

 

[overbore]

Thanks for the reply

Is there a place that anyone has seen that show it
in a graph or something like I have seen on a two
stroke site,that really helped me years ago understand
how they all tie together so you can understand
different areas of throttle response.
like if you just having problems off the bottom then look
for the slow air and fuel jet and needle,ect.
Dont know how to ask it any other way.
Thanks overbore.

 

[Ol'89r]

Is there a place that anyone has seen that show it
in a graph or something like I have seen on a two
stroke site,that really helped me years ago understand
how they all tie together
Thanks overbore.

overbore.

Sudco International used to have a neat little chart in their catalog that showed the different jetting circuits and how they overlap.

You could try their site at www.sudco.com

Good luck.

Ol'89r