Tecumseh 8 HP hesitates/stumbles

[creia]

1974 Tecumseh HM80 - 155042A mounted on a Heald Super Bronc "adult-sized" minibike.
When I open the throttle very quickly from a stop (idling) it very briefly hesitates/stumbles then will go WOT as normal. If I open the throttle slower it will not hesitate. Is that generally a too LEAN condition or too RICH condition? Is the correction with the high speed/main mixture needle or the low speed/idle mixture needle, or BOTH? Other than that the engine idles and runs very well.
Thank you for any help,
Michael

[KE4AVB]

Congrads you just discover why they added accelerator pumps to a lot of 2 and 4 cycle carburetors. You can try running the idle mixture a little on the rich side but that hesitation will always be there as of the small engine weren't design for sudden rapid acceleration.

Matter of fact many of the Zama 2 cycle carburetor have a form of accelerator pumps built in. Some Kohler carburetors also have accelerator pumps. I remember I use to have nightmares with accelerator pumps on my 4 barrel Holley on my 67 Chrysler 300 440 High Performance engine.

[creia]

Thanks for the reply- much appreciated.We have had various Briggs, Tecs, and even Honda engines. This is the first one that we have had with this kind of stumble/hesitation when you do a quick throttle "snap", YET still idles well and overall runs very good otherwise. I'll try adjusting/richening the idle mixture about 1/8 turn.
Regards,
Michael

[creia]

Another follow-up question. Will a LEAN carb setting produce a faster or slower IDLE rpm than normal? I have had some trouble getting this engine to idle down to the proper rpm- it tends to idle a bit fast.
Thank you,
Michael