ZCar Forum banner

Status
Not open for further replies.
1 - 7 of 7 Posts

·
Registered
Joined
·
181 Posts
Discussion Starter #1
OK, I gathered from you guys (Most, anyway) that the dome carbs are a better route. I tried to rebuild the flat tops I have but couldn't get the **** float pin out (Any suggestions?). Soooo... I put the domes on... it starts right up but just starts revving high as **** then goes back down... up, down, up, down. Plus it keeps backfiring through the front carb. Anybody know whats going on?? I apologize for my inexperience but this is my first Z! Thanks a bunch!
 

·
Registered
Joined
·
1,713 Posts
You're definitely better off learning on round-tops. Much easier to deal with.

Backfire often said to be related to lean carb condition, although in my experience it was more related to flakey brass intake seats. Be sure at least to double check your valve lash.

Massive rpm surge probably related to vaccum leak. Engine should not be able to draw enough air to rev like that through the carb throttle plates at idle.

Ztherapy video $15 highly recommended.
Good luck!
Al
 

·
Registered
Joined
·
181 Posts
Discussion Starter #3
Thanks Al.... I didn't expect a reply from a die-hard flat-top fan!! :) I guess I'll have to check for vacuum leaks when my wife can start it for me... of course if I stay in the car it will stay running, but as soon as my foot hits the dirt - out she goes!
 

·
Registered
Joined
·
181 Posts
Discussion Starter #4
by the way, it ran fine with the flat tops on, but the rear one was shooting gas all over the place... that's why I took them off in the first place. I'm just thinking maybe I overlooked plugging something or something or something... I plugged the holes that went to the old carbs and stuff, should I not have done that?? Ugh, I just don't want to go crazy and push it off a cliff............. No BeEr AnD nO z MaKe ShAyNe Go CrAzY!
 

·
Registered
Joined
·
181 Posts
Discussion Starter #5
Oh, and if I use the domes, I'll have a set of "boat anchors, doorstops, paper weights, wheel chocks, shotputs" to get rid of if anyone's interested.
 

·
Registered
Joined
·
1,713 Posts
Start with all vacuum accessories and smog stuff plugged. After you get carbs running and vacuum leaks under control, carefully reinstall vac lines. Recommend you keep at least:
line to dizzy advance w/ tee to carb can control dashpot.
anti-backfire valve.
egr. (lot a folks hate egr, but I think it is a good thing with no performance penalty).
vac brake booster.
crankcase ventilation system.

Good luck!
Al
 

·
Registered
Joined
·
685 Posts
This may help you get started in adjustment.under the carb there is a adjustment knearled "knob" turn it up all the way , that is turn it couner clock wise, untill it stops. Then back it down 2 turns . do this to both carbs. then start the engine and it should run and idle. If you go to the search section on this web site and pull up adjusting SUs You will find all the further instructions needed. If you dont have to pass emissions , you can set up the engine to run as it was designed to run. My 73 L24 now runs like a watch and gets 20+ mpg. A uni-sun to ballance the carbs is a must. $25. or so at the local parts store or speed shop. Gary Portland Or good luck
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top