# Zuma adjustment screws



## Dunwood (Jul 14, 2007)

*Zama adjustment screws*

First post, newbie. Great resource! Decent mechanic. 

Eager Beaver McColluch blower. No primer pump on this one. Its been sitting a few years, had zero fuel in it. Replaced the broken fuel line and new filter. Fuel tank cleaned out. The air filter had very little debris or even dust in it, therefore this is probably a low usage unit. Belonged to my dad. 

Zama carb. Got it started, doesn't low idle too well. There are three screws: One directly before the throttle plate. A second one closest to the engine and one furtherest away from the engine. 

What is the process for adjusting these screws. And which screw is which. I suspect the one directly before the throttle plate is the idle speed (not idle mixture). 

Thank you in advance!


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## 30yearTech (Sep 14, 2006)

The two screws side by side are the mixture screws. The one closest to the engine is the low speed or idle circuit, and the one closest to the air filter is the High speed or load adjustment. There is usually an "L" and an "H" next to each of these screws cast into the carburetor body.

Turning counter clockwise on either of these screws will "richen" the mixture and tightening down on them will "lean" out the mixture. Start with the screws backed out 1 1/2 turns from seated position.

If the diaphragms in the carburetor are stiff, you may never get the carburetor to adjust properly. Many times the diaphragms will dry out and get stiff when they set up for an extended period of time.

You can obtain additional info at the Zama Carburetor site

http://www.zamacarb.com/tips.html

Good Luck.....


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## Dunwood (Jul 14, 2007)

Well that was my first problem, I used the search function first and mis-spelled ZAMA. Thank you!


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## geogrubb (Jul 28, 2006)

Dunwood, welcome;
Hankster and 30year are some of the best on this forum, enjoy. Have a nice one . Geo


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