cletus

Ok, many of you may be familiar with my plight to change a carb and get it running right.

The third screw to hold the butterflies open at idle waas missing on my carb. The ones from my other 2 carbs were too long to fit in there with the other stuff on there. Instead for now I adjusted the throttle cable to it always holds it open. I'll probably go find a short screw for it at home depot.

Now, she will idle. But she will not idle very smoothly until about 2k rpm. It has the little like "putt" sounding misses or whatever is going on. The car has always done that. But if I'm below about a 1800-2k idle it does it excessively. The exhaust is aftermarket if that matters.

I was told from the guy I got the carb from that it was "bored out" and he said it would idle higher than my stock one did. That's quite a bit higher. I know nothing about what is what on a carb and really what boring a carb entails unfortunately.

Any suggestions on where to go from here? Remember I don't understand carbs too much, so simple man's terms please

On the bright side, she starts a ton easier and seems to have better throttle response (doesn't stutter if you just tap the gas quick).

Thanks again. I know you guys are sick of hearing from me.

hanman

cletus,
I can't remember the specifics from your first post, but......What year carb? 81 or newer?
I would say that you need to adjust the air mix screw, but if someone did mods to the carb all bets are off. If it was Paul Yaw, fine, but anyone else I am not qualified to comment on. Sorry,
hanman

cletus

I think it is an '83 or newer carb. My car always did idle a little high. I may run it to someone who knows about carbs to look at it now that it is atleast drivable.

cletus

I'll tell you what though. She runs beautifully now though. Smooth transition to the secondaries (my old carb was almost like a turbo coming on sharply with a nice jolt). Runs great all the way up to redline. Need to get her in to some hard corners to see if she dies on my like my old carb did. My guess is no. I need to go get that screw and get that in though so my idle doesn't drift around a little like it does with the butterflies being held open with the throttle cable. It'll vary from 1500 to 2500. I'm shooting for 1500 for now for an idle .

hanman

cletus,
make sure that you don't have an air leak somewhere. If you have a bad leak, it will suck fuel in from the carb and you will never be able to set the idle down where you need it. Try spraying WD 40 or ether (be careful) around possible leak areas, i.e. carb and manifold gaskets. Another way is to use a propane torch and introduce the raw gas to the possible leak areas.
hanman

cletus

I'm taking it you do this to see if the WD40/ether gets sucked in through the leak point and you'll be able to tell if it's getting burned in the engine.

Does this still work with WD40 since the stuff no longer burns (stupid new formula is no fun )? Cause I have no idea where I'd track down ether .

I mean technically I can set everything to idle at like 700 if I wanted to, it's just really really rough. Does that really sound like a leak or possibly the carb being modified or whatever. I really just have no idea what I'm talking about .

jeremy

iTrader: (1)

you sound like me man.

its the flubagaster. mine was blown on my carb. nothing a little duct tape and bailing wire wouldn't fix though.

fuel injection..................

hanman

I didn't realize there was a new formula for WD 40. It needs to be flammable. If you use ether (starting fluid, any auto parts store) it will work. When you find a leak the engine will idle up immediately. The more fluid you spray around a leak the more the engine will race. I like the propane torch trick because it is not so dangerous. Starting fluid is pretty scary stuff. You can also use a spray bottle with water in it, it will have the opposite effect on the engine.

If you can get it to idle roughly at 700 rpm, my suggestion is to take it up to 900 rpm and then enrichen the mixture (air mix screw) until it smooths out. You will then have to lower the idle back down to 900 rpm again. I doubt it will ever idle below that if you have had the venturis bored out.
See how that works.
hanman

REVHED

If it's been bored out then I wouldn't bother trying to get the idle too low. Around 1000-12000rpm should be good.

Here's the way I used to set the idle when I was running a modded Nikki.

1. Turn the idle speed screw (the top one) all the way in till it seats and then out 2 full turns.

2. Adjust the throttle position screw till it idles at aproximately the desired rpm.

3. Turn the mixture screw clockwise until the rpms start to drop and then back out 1 turn.

4. You can now use the idle speed screw to fine tune the idle speed. Just remember repeat step 3 afterwards.

cletus

I'll try that. Thanks. Right now though that carb is missing the throttle position screw. The one of my other carb is too long to fit oddly enough. I'm gonna head to home depot and get another screw that is just shorter. Anyone happen to know thread/size?

geikiganger

If there's a new formula for WD40...why isn't it WD41? I thought the WD40 had something to do with what chemical it was...

cletus

They just slightly changed so it is not flammable (or atleast not as super highly flammable as the old stuff). Apparently people were blowing up or something.