I rejetted my Z last sunday due to a lean surge at cruise and drove it to work..and it ran just fine until I came to my first red light..I let off to slow down and it stalled.Restart..no big deal.Problem is anytime I am driving and let off to stop..slow down ..whatever it stalls unless I tap the throttle quickly to get it to stay running..once I do that it idles just fine.Its a Demon 750Dp.78/85 jets.Idle mixture is set for highest vacuum.Throttle plates are correct..the secondaries are closed to just below the idle transfer slot..and I get no vacuum at idle in the ported side so I know the primaries are not open to far.Float levels are aroung half way in the sight plug.Please help..this is getting aggravating.Ran fine before I jetted but it would do it occasionally...but now it is all the time.Please help!I was just starting to enjoy my Z and now I want to burn it!

 

ohhh grasshopper you must apply patience before passing judgement of the burn. I had this problem on mine when I rejetted. I ended up having to bump my idle up just a little from 600 to 750. not sure if this would fix your problem just thought id let you know

ps: by the way when is pappa smurf going to make it to island dw ?

 

I'll have to give that a try..willing to try anything right now.Need to get her running good for the cruise-in saturday night in middletown.Island is soon...just need drag radials!Damn bills..kids..house...lol

 

hell I got those 28x9x15. half wore out. 100.00 takes them.

 

DAMN that's a lot of jetting. I run 76/81 jets in my 850 Demon and I'm fine with a 408 and a pretty big cam. I'd say you're giving it too much fuel ...

 

I also thought that was large jetting for my combo but any smaller on the primaries and it will surge when cruising..almost miss.And on the secondaries I try to keep the 7 split so that leads me to the 85 witha 78 primary and I have to say it pulls noticeably harder than with the 83's.I am thinking I will open the secondary throttle plates a hair more and see what that does.I'll just keep tinkering till it stops stalling.

 

How is the ignition system? That can give you a 'surging' problem. Running that big of jets, when you let off the throttle the engine was getting 'plenty' of fuel--that fuel is in the intake and you cut off the air(by letting off). It will create a rich condition. Not usually bad enough to cause it to die though. Like he said above, up the idle a bit. Lean the idle mix as much as possible--but still running smooth. Try the float level at the bottom of the hole. What are you running for ignition parts?

 

Brand new MSD pro billet 8361 distributor..brand new Blaster SS coil..6AL about 5 years old.MSD super conductors 8.5 3 months old..fresh Autolites 3924's.

 

The jetting combo is what the carb and motor want. There is no set standard should or should not. I used to think that way but figured out it was wrong. I run 78-86 in a 355, afr heads, 224-230,530-540cam. Anything smaller and it would not run as good and it would lean surge going down the road. Just like the split. There is no rule on the jett split, its what it runs best with.

Drew