22R88

No real problem, just want to understand. I push my pedal twice, hit the key and it fires right up, but the rpms are hovering around 2,000 for about a minute and the engine sounds choppy until I slightly gas it or just wait and the engine smooths out and revs to about 2400 till I pop the throttle off of the choke cam and it idles down to about 1500 till it gets warm then it idles around 800 rpms slick. What is the non smooth running at first crank from and what controls the idle to fall down to 800 after the engine begins to warm.

Thanks,
22R88

peow130

Yeah that sounds normal for a carb that old. Mine gets up to about 2500 if i let it, then i touch the skinny pedal and it plummets to 850 or so

Non smooth running is from an old carb being loaded with years of junk gas and particles.
The cold idle thingy

Zim

This link is the best I have found when it comes to 22R factory carbs. Hope it helps.

http://www.bluebassdesign.com/boonin/carb_faq/

22R88

Thanks Guys !! Appreciate the advice

abecedarian

Honestly, you should only have to "pop" the throttle once. That should be sufficient to add some fuel from the accelerator pump to the intake, giving you a rich mixture to start.

After that, the choke should be closed, which cuts off some air to the engine, and the steps on the throttle cam shaft should hold the throttle open too. It should start up and idle fine, maybe around 2000 or so, and should start idling lower after a few moments / minutes as the choke opens.

If it idles "up" from a cold start, I would really worry about that- think that this is a mechanical thing that can only approximate perfect conditions, and a "step" on a cam is not a variable thing but is rather a "hard" jump from one point to another.

Maybe we could argue that a sloped cam with a bearing for the choke and throttle positions would be better, but we are talking about 1980's tech here, no?

And if carb's really were better, we wouldn't have EFI, would we?