Running rich(long)

[audijunky]

Allright fellas here it goes. Some of you may know the story so I will get right to it. 79 Standard, Pod filters, open header, 145 main jets, 45 pilots, new floats, brass(not adjusted or measured yet),I have used the washer in the exhaust pipes trick to add back pressure. I had two of my idle adjust/mixture screws break off in the throat of carbs 1&2. I could not get them out by any means so I drilled them out.I know probably the worst thing I could do. But it is done, 1/16 drill bit. I ran it for about 120 miles this weekend in this state. Accelerated well after about 3k rpm. The idle would hang up after I would come to a stop, unless I let the clutch out a little to bring them(rpms) down then they would stay down. 1,2,4 spark plugs came out wet and black, I mean really black. Up the threads of the plug black. I have a dremel kit that has this conical shaped tiny bit , so I cleaned the holes up (1&2 carbs)with that and used a same sized grinding bit of sorts. I noticed while doing this that I had #4 screw turned way out. So as of now I have Cleaned out this passages of any debris,inserted all of the idle mix/adjust screws to lightly seated and turned them back 1 1/2 turns. I have not tried it yet, but while the carbs are off I figured I see if any one had any other ideas for me to try. Thanks for your patience
Steve

[Brian_D]

Steve,

Set the float height before re-installing the carbs.

Then sync the carbs to eliminate the high idle rpm - should follow the sync with a pilot screw adjustment and final sync.

[mro]

What Brian said.

If you think it accelerated well before,
you will really like it after setting floats and the sync.


mro
btw, exhaust sound/tone change after washer installed?

[DiverRay]

Steve, Brian is correct. You MUST set all floats to the SAME level. Check both floats in each carb, as they can vary a few mm. Then sync the carbs, adjust the pilot screws, and resync carbs. This sounds like a lot of work, but takes about an hour to do everything. DO NOT FORGET TO HAVE A FAN COOLING THE BIKE!!! If you try to sync the carbs without a fan on the engine, you WILL ruin the engine, quickly. An air cooled engine will overheat in about 5 minutes with no airflow. This is NOT dependent on the outside air temp.
Ray

[audijunky]

The tone of the exhaust changed a little. I think I heard a difference but my father in law thinks it sounds the same. Still a head turner/screamer. I think I may have lost a little top end though. I only ran it for a few minutes, so we''ll see next time I get it warmed up. So does any one see any problems with drilling out the mixture screw holes. I imagine the fuel amounts going through would be the same, but I wonder if it will change the way it gets mixed with the air. I have ridden it since drilling and really didnt notice a difference. Below 3k kinda weak and gimpy, sputtery,after 3k hold on tight. Thanks for all the info fellas.

[DiverRay]

The below 3K IS the pilot circut. If you have black plugs, and no bottom end, you do need to adjust the pilot screws. You will need to get the pilot circut correct before you can move on up to the mid and main circuts.
Ray

[audijunky]

Does this include the float adjustments/measurements
What about needle jet adjustments

[Brian_D]

If you are asking about the jet needle position, I believe the clip is located in the 3rd slot for stock jetting.

My limited knowlege of the carb workings tells me that the jet needle position *SHOULD* only affect the higher rpm range - vacuum increases, which pulls the diaphram assembly up, thus raising the jet needle and allowing more fuel flow thru the main jet.

[John]

The symptoms you describe are definitly in the pilot circuit, and it sounds like the pilot screw orifices are too large, and it is too rich for low speed operation. When you accelerate past 3k, the jet needle will raise to allow a lot more air in and lean out the mixture. I would say to turn the pilot screws in a little on the carbs that have the enlarged holes. I had to drill out a broken screw tip last year, and I used a #60 drill bit in a pin vise to do the job. I could have used a little smaller drill bit, like a #58, but I couldn't locate one, #60 was the smallest I could find.
On the jet needles, I believe the stock clip setting is in the center groove.

[skids]

I had to drill out two of 4 carbs pilot holes on an H model this summer. It still gets good fuel economy on the highway (38mpg) and idles fine, acceleration is about the same. The difference is that when coasting down a long grade, it seems to hurt the economy a bit, as if the extra vacuum is sucking more gasoline through the bigger holes. Normally you would expect better economy dow grades with the throttle mostly off.

Originally posted by audijunky
So does any one see any problems with drilling out the mixture screw holes. I imagine the fuel amounts going through would be the same,

[TopCatGr58]

Hey Steve,

Don't know if you saw the tip PGGG had posted a while back, but using some JB-Weld, putting just a small amount over the pilot screw hole on the throat side of the carb, then screwing the pilot screw down so that it would just poke a little hole thru the JB-weld, then back it out a bit and then let the JB-weld set. You don't need to use much, and make it fairly thin and flat around the hole. This can reset the hole back to its smaller size, then retune the pilot circuit either by sound or colortune.
T.C.

[Goin Commando]

I have had to drill out one of my air/fuel mixture holes on my 79 Special, now I can only turn the screw out about 1/4 turn to get a good idle and plug reading from that carb. What ever the size of your new holes are, will determine how far you can turn your screws out. If you are still using the broken off screws, that will make things even harder to adjust.
I tried a JB Weld fix on a carb related problem twice, in time they didn't like the gasoline and both times it failed. It could have been opperator error though. I can't help but to wonder how your motor would react to having a chunk of JB sucked into it.