HELP WANTED on carb issue!

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   I have a Zenith 7078-C   carb. that is dual fuel for my 35 WC , I have back together with a rebuild kit and gaskets and have  put it on the tractor . how many turns out on the air and fuel needle for it. The carb kit didnt have any info with it and I have almost had the big one trying to hand crank it. It has new paint and just cant bear to pull it off and the new engine dosent help matters.    thanks for the help !  Mark-east-tn 

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mark-east-tn Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 06 Oct 2009 Location: Rutledge Tn Points: 761	Post Options Post Reply Quote mark-east-tn Report Post Thanks(0) Quote Reply Topic: HELP WANTED on carb issue! Posted: 25 Jan 2010 at 8:45pm
	I have a Zenith 7078-C carb. that is dual fuel for my 35 WC , I have back together with a rebuild kit and gaskets and have put it on the tractor . how many turns out on the air and fuel needle for it. The carb kit didnt have any info with it and I have almost had the big one trying to hand crank it. It has new paint and just cant bear to pull it off and the new engine dosent help matters. thanks for the help ! Mark-east-tn

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AndrewGubbels Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: nebraska Points: 1515	Post Options Post Reply Quote AndrewGubbels Report Post Thanks(0) Quote Reply Posted: 25 Jan 2010 at 8:50pm
	You want to turn it clear in and then back out about 4 full turns. That is where ours is set and it runs really well. One thing that is probably not helping, if it has set for awhile everything is so dried out in the manifolds that it will take some cranking to get everything as it should to fire. I hope this helps. Andrew
	Andrew Gubbels Gubbels Restoration

Gerald J. Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Hamilton Co, IA Points: 5636	Post Options Post Reply Quote Gerald J. Report Post Thanks(0) Quote Reply Posted: 26 Jan 2010 at 10:14am
	The preset is only close enough to make it hopefully run so you can refine the adjustment running. Gerald J.

Dick L Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Edon Ohio Points: 5087	Post Options Post Reply Quote Dick L Report Post Thanks(0) Quote Reply Posted: 26 Jan 2010 at 1:20pm
	Just remember one adjustment has nothing to to do with the other. The small adjustment is for the idle adjustment. You can turn them both out 2 or 3 turns the when it starts you adjust the idle first. You want to alternate small adjustment between the needle and the stop screw on the butterfly lever at the back, working the throttle lever down/back. You want to get it to run as slow as you can get it to run without stopping. That will take a little fussing and restarting of the engine. When you get the idle where it needs to be then open the throttle wide open. You then adjust the power jet to the highest RPM. Then you turn the adjustment screw until you notice a slight lower RPM. Thats alls theres to it. The idle adjustment screw adjust the air with the fuel for idle only. The higher RPM's draws the air into the engine and the power jet adjusts the correct amount of fuel into the air stream.

Dave(inMA) Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Grafton, MA Points: 2399	Post Options Post Reply Quote Dave(inMA) Report Post Thanks(0) Quote Reply Posted: 26 Jan 2010 at 6:19pm
	Dick, for some reason that description of adjusting a carb is about the clearest I've ever read! Perhaps it's just your choice of words, I dunno. Thanks.
	WC, CA, D14, WD45

Gerald J. Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Hamilton Co, IA Points: 5636	Post Options Post Reply Quote Gerald J. Report Post Thanks(0) Quote Reply Posted: 26 Jan 2010 at 6:51pm
	If you do not get the speed really slow for the idle adjustment (e.g. throttle plate closed tight) there will be interaction between the high and idle mix adjustments so you have to do the sequence several times to get it optimized. Then setting for maximum engine speed lightly loaded near the normal maximum rated engine speed, but unloaded does not use fuel like being loaded and it may take a bit of tweaking under load to get maximum power. Maximum power will be on the rich side of the fastest running. Gerald J.

Rogers Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 16 Sep 2009 Location: Georgia Points: 2176	Post Options Post Reply Quote Rogers Report Post Thanks(0) Quote Reply Posted: 26 Jan 2010 at 8:31pm
	1. For a Zenith carburetor you start at 1-1/2 turns out on the upper air needle and 4-1/2 turns out on the lower gas needle. This should be good enough to allow the engine to run. 2. After starting open the engine to about half throttle and let it run for a minute to warm up. 3. Close back on the lower main gas needle until the engine begins to run lean starving for gas. 4. Start opening back up on the lower gas needle until the engine begins running rich keeping up with how many turns you opened it back up. 5. Leave the main gas needle set half way between lean and rich. I have found that the final main gas needle adjustment is about ¾ to 1 turn open from where the engine started starving for gas, and the air needle ends up staying at 1-1/2 tuns out. Edited by Rogers - 26 Jan 2010 at 8:32pm
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