Jake, this is the shape of my plugs after about 10 min of idling.
1.7 (now a 2056), dual webers, 009 dizzy (PO), my jets are Main 115, Idle 50 not sure the air, Idle screw is screwed as far in as possible just to keep car idling (still the idle falls off and stalls), reving the engine smoke come out exhaust (new rings over the winter and never had the car on the road). I havent been able to time it, cant get a steady idle. Tried this weekend to take it for a ride and hopefully seat the rings, made it about 200 yards and it stalled (bucked and jerked the whole way). Had to pull plugs and clean them to get car started again, and put it back in the garage. Any ideas?

Heres another photo of the plug

the idle adjust is turned ALL the way in? . if that's the case you should be idling at about 3000rpm. start with the air mixture screws at 2 1/2 turns out from being gently seated. close or turn the air by-pass screws out 1/2 turn. what size webers are you running? i think your linkage is the first issue to address. on my webers i don't use the idle adjust screw on the pass side carb. i use the threaded rod to match the flow on the one with the idle screw, then the one idle stop controls both carbs. first, pull the idle jets and make sure they are clear. show a picture of your linkage. buy Thomlinson's weber book from cb preformance and get a unisyn so you can match the flow rates.

kevin

Kevin, I have dual 40 IDFs, I have the weber book and tried to do the steps for adusting the carbs. With idle screw at max I am only idling at about 500 and it will die of if you arent playing with the throttle (it doesnt idle to smooth, as you can expect, it will idle for a little while, and either rev up slightly and then down or just sart to die, I think because the plugs get fouled). I have used the unisysc and they all seem to be pulling in the same amount of air. The mixture screw is turned all the way in lightly trying to lean out the mixture and the air mixture screw doesnt seem to make a difference. I rebuilt these carbs a few months ago with a kit I got from someone in Italy on evilbay, They were for the newer weber and I have the older ones (I did buy the older accel pump diafragm and replaced it). I was wondering if the person I bought the webers from didnt ream the jets?

hows the fuel filter? what type of pump and fuel pressure regulator? the "hunting", up and down idling is weird. if you pull one of the fuel lines do you get good flow? with out a stable idle the unisyn is useless. did you look at the trouble shooting symptoms and proceedures?

kevin

Fuel filter is new and I have the rotary fuel pump from CB that has a built in pressure reg. I have plenty of fuel going to the carbs, There also was fuel in the oil, trouble shoot seems to be to rich a mixture, that is why I had to turn the mixture screw in all the way. If this happened to one side of the engine I would assume air leak or something, but to happen the same to the two carbs is strange.

check procedure #4 in the trouble shooting guide in the cb book. seems to be narrowing down to the float level. did you get the pump with the lower pressure rating?

kevin

The pump is for carbs, I did have to sdjust the float on one carb, would overflow. It should be set to the spec from the weber book, should I play around with the level?

with the fuel pump running and the engine off do you see any puddling on top of the throttle valves/butterflys?

Those look like Champion plugs... Please tell me they aren't...

Is there a certain brand of plug we should be running?

i use bosch

Champions are the worst!

I run Bosch exclusively.

Jake sorry to say they are Champion, went to my flaps and bought them before I knew any better. Which plugs are the best?

Bosch... I could tell they were Champions- thats probably why they are trying to fuel foul already..

I won't even use a Champion in a damn Briggs and Stratton!

They are also notorious for ripping the threads out of spark plug holes.

Two words- They - suck -.

Jake from what everyone else says my problem is definatly over load of feul, would the bosch plugs resolve this? What else should I lookm for, I am going to play with the floats sometime this week.

They fire hotter and may help it a bit..

The engine needs to be tuned at higher speed than idle- it must be driven and then go from there. Most aircooled engines do idle richer than they operate, especially when they are cold-

Bosch plugs have rolled threads, Champions don't.

But he can't get it to run long enough to even warm up.

Have you tried replacing the idle jets? If you can screw the idle mixture screws all the way in and not have the car instantly die, the idle jets are WAY too big, or you have fuel leaking around them. Buy a set of 52s from a known source, like aircooled.net. Remove the idle jets and blow out the holes they sit in with air before installing the new jets. Make sure all of the jets in the carb are present and properly seated.

Do you see any fuel coming out of the accelerator pump nozzles (in the carb throats) while the engine is idling? Does any come out when you blip the throttles? None should come out unless you open the throttles. If some is dribbling out all the time, there's the source of your extra fuel at idle.

The low idle can also be ignition mis-timing, probably way too retarded. Since you've said you've not been able to time it, I'd say this is likely. Try advancing the ignition (turn the distributor clockwise) a bit and see if that speeds up the idle. If you can keep it running long enough, turn the distributor clockwise slowly until the idle is at max speed, then readjust the throttle stop screws.

You can statically time the ignition w/o the engine running, as well. Set the engine to TDC on cylinder 1 (see the various tech articles on how to do this), set the distributor so the rotor is pointing exactly at the mark. That's 0 degrees advance. Now, turn the distributor a bit clockwise, trying to get about 5 degrees at the distributor. That's 10 degrees BTDC ignition timing, which is about right. You can adjust it again once you can get it to idle, but that should be enough to get you in the ballpark, and eliminate timing as the problem. You might also replace the points and condensor if you haven't recently. They're cheap, and can cause idling problems if they're going bad.

I was going to pick up an jet plug guage to check all the jets to see if they have not been reamed. I havent checked if fuel is going in the throats at idle (If the car stalls I notice fuel pouring onto the closed butterflys on one carb. Because this engine has been worked by the PO there was no timing marks on the impeller and the dizzy drive was way off the TDC mark, I had to go by the mark on the flywheel but couldn't be certin this was right. PO put in the 70 1.7 on the 74 side shift. I tried doing the timing by ear, keep turning one way then the other to get the idle right. Points, condenser, rotor and cap have been replace on the 009 dizzy.

The idle jet holes are VERY small, and I don't know of any spec that tells you how big the hole is supposed to be for, say, a 50 idle. If this tool you're thinking of costs more than $20, buy the jets instead. Then you'll KNOW the jets are the right size. Personally, I don't think this is your problem, based on the other things you're saying. I'd leave the jets alone for now.

If you've done the timing entirely by ear, it's possible its 180d out. The engine will run in this configuration, it just won't run well. Idle will be rough and hard to control, and you'll have no power. You can get TDC on cylinder 1 with certainty by just pulling the plugs and the valve covers. When both rockers are loose and the No.1 piston is at TDC (easy to tell with a plug out, using something like a long zip tie poked into the hole), then that's TDC on the compression stroke for No. 1, which is near where the plug should fire. You need to be CERTAIN the timing is close to correct before you spend any more time futzing with the carbs. Like Jake has said elsewhere: most carb problems are actually timing problems. If you can't get it to idle at all by fooling with the carb, I think you're looking in the wrong place.

If fuel is pouring into ONE of the throats with the engine off (but the pump is on), then I'd say you still have a leak in that throat, and that leak is 90% certain to be in the accelerator pump circuit. If it's BOTH throats on one carb, you have a stuck needle valve, a bad float, or a misadjustment of the float, still.