#1 and #2 spark plugs are black. #3+#4 are not so black

Been around on here and see carb vents can cause that same problem. I feel rediculous but I don't know about the vents. Don't know where they are at or what is being considered a vent, let alone how to see if one is plugged. Nothing should be plugged though. The carbs are very clean right now and should be well tuned. But one side is black, the other is a little black. His name is "Raaaalph, man.
Anyway, any suggestions as to what I should look for. Some measures to take to fix the problem. Should I resynch them. etc...
Oh yeah, the shop guy said I might not have done the adjustment right and there are things in faulty valve adjustments that will cause this to happen. So it looks like there are a few possible causes. I want to eliminate the ones I can do myself before i have it looked at.

 

Anybody?

 

what part of wisconsin are you in?

 

Southern wi. Close to milwaukee.

 

bummer, i was hoping you were closer to the U.P.

the only carb vents i'm aware of are on the airbox side of the carb "throat". the vent right into the bowl - there are 2 jets in there, they are pretty large and not likely to clog, but if they are clogged, it wouldn't allow the bowl to fill properly.

edit:
based on what i saw you posted in the "only running on 2 cylinders" thread - i think the vents your mechanic was talking about are the YICS ports. I kinda doubt a blocked YICS passageway would be the cause of your issues.

if your valves are in spec, i would guess it's most likely a sync issue.

 

It is most likely a funky synch issue. I posted the same question on Yahoo answers (just in case I got lucky) and a guy tried saying a bad sync wouldn't cause the bike to run bad except at idle. I don't think I'll be going there anymore. Not for engine advise. I've had badly synced carbs keep me under 4000 rpms, had problems with flooding, rough running, bad idle, and different problems from low to high range. I am thinking he is under the impression that syncing carbs is all in tuning the pilot jets or something. Who knows. Just hope it's a sync issue. I am going to have the valves gone over again to make sure I didn't screw it up.

 

I had the same issue with my bike, where 1 and 2 were black, and 3 and 4 were close to perfect brown.

This puzzled me for months, and no amount of synching or fiddling would fix it ... I just rode it as is and then eventually all 4 plugs turned too black

 

You're running pod filters. Have you checked that 1 & 2 pods are clean? Black plugs would suggest running rich, which can be caused by a restricted air flow through dirty pods. Might be obvious info you've already clarified, but I've learned hard to always check the easy stuff first..

There are vents at the carb intake end, tiny pin-sized holes. But I believe this is the cold start tubing, so only applicable on startup. I could be very wrong on that, of course. But if your carbs are very clean, clogs shouldn't be the problem. Maybe the carb pistons aren't sliding freely (clunk test)?

Anyway, just theory diagnosing.

 

It may be that.Igotta check it out. Been looking for the write-up on clunk testing. I had seen something on here before.

 

uhh, theres an awesome video on clunk testing, however it got removed from the site or something because the user was inactive...

but take the top off the and the spring out, push up the slide from the bottom, then remove your finger, it should fall as fast a a gee-a-teen (yess i dont know how to spell it) , or bassically, it should as fast as if you just grabbed the slide out of the carb and dropped it to the ground

you should also hear a resounding "cling" like a hammer hitting an anvil

 

Well... they clunk. So still figuring things out. Oh well. I just thought of something though... Just put a new exhaust on the bike. It went from having a torn up header assembly where the stock header were broken in some places from the collector. Now I am not only running a new, solid exhaust... but its a 4 into 1 which I'll bet makes a difference with tuning and syncing.

 

Running progessively worse in all rpm ranges.

 

hopefully just running worse now because your plugs are getting blacker and blacker. if you can make it to the UP, i have a colortune and vacuum gauges . . .

changing the exhaust could certainly have an effect. especially if you went from one that was, as you said, banged up and separated from the collector.

+1 on the pods being dirty, too.

 

with 4/1 and stock air box you should be kind of lean , with pods you should be real lean
the sync won't have much effect past idle unless your in left field
make sure the fingers on the choke plungers don't even come close to lifting them
you did shine up the plungers and their seat down in the carbs, right ?
with a MAC 4/1 i was running 126 mains and shimmed the needles .04
and that was close but thats a 750
now i see you got a 550 so maybe forget all that ????

 

So I went for my ride this morning and figured I'd try running on PRI with the vacuum plugged. It ran smooth this way, hit on all 4 the whole way through, idled very smooth but it compromises my performance in two ways. My throttle response is not the same, of course. If I throttle too much (unless I give a quick shot of rpm right before takeoff) it sputters for a second before getting the response. And my top end (in 6th gear only, it seems) isn't as sprite as it was. I still have better pull than I did with the airbox and stock exhaust and can still get up to around 125 mph (about top speed now) but its slower than before.
I have a couple of experaments I want to try but don't really know what could happen.
Does the vacuum line have to be on #2 or can it be on any of the carbs? Also since I am running on PRI and just using gravity, I think I need to pull the in line filter. First of all, it is installed backwards. Can't see that having much of an effect. Second, it empties while I am riding. The carbs are pulling more fuel then the petcock is letting out. That is the same for when I have the vacuum line hooked up.
So I am thinking of just running the bike on PRI as it was when I first bought it and running a shorter fuel line with a charcoal filter that goes more directly into the carbs. Right now it looks like a snake winding its way down.
Any thoughts?

 

different filter and shorter line might help keep the line from pinching. Mine had a longer line and I found after a while the line would pinch and keep it from suypplying the carbs gas. I don't think it matters wich carb vac tube you use.

 

You said the carbs were "Well tuned". How did you set the idle mixture screws? Sounds like the mixture could be too rich and when you twist the throttle, Your giving even more fuel.The plugs can't burn all the extra fuel and therefore turn black. I would give the mixture screws a 1/4 to 1/2 turn in on those cylinders and see what happens.
Putting the "pet" on prime continuously delivers fuel to the carbs. Not a good thing for carbs that are already getting too much. JAT

 

Well I thought they were well tuned too. haha... It started (and still does) at any temperature. If I leave it alone from one morning to the next, go out and press the start button, it'll start. The problem started after the first couple of rides and got progressively worse. So i was wrong about the carb tuning. I wish i could do this stuff myself.
I had the carb work done at a shop. Redline in kenosha. If i turn the idle mixture screws in and everything works out and the bike idles fine, what about when I am riding? Then I am dealing with the main jets, right? The problem seems to come more from riding. Maybe i need to study carbs. I can take them apart and rebuild them and clean them thoroughly. But when I do that, I usually just set everything back to what it was before by counting turns of the screwdriver.
With the PRI on and the vacuum disabled, it seems I am running leaner than when it is set up correctly. Still running rich but not as rich. I would much rather be running with the vacuum operating than not. Just hate taking it to a shop. I am going to learn how to tune these damn carbs myself. Or at least the basics. this site has brought me a long way so I'll bet I can learn that much.

 

Do a forum search and build yourself a two-bottle vacuum sync rig and sync the carbs before you start twiddling with the mixture screws.

You've already taken it to a shop, that didn't work out so well.

One last item, has nothing to do with your issue though: As the owner of TWO very well-tuned 550 Secas, I can say that unless you have drastically altered your final drive gear ratios, a 550 won't go 125. Top end at redline is around 116, max. Sorry.

 

Buy a new filter and install it correctly. If you just turn the old filter around your going to get any particals the the filter traped straight in to your carbs. May sure your fuel line isn't to long and winding around (short line-filter-line to carb)
Now it sounds to me like your petcock may be plugged up with the filter going dry when running, get it off and cleaned up maybe order a rebuild kit for it from chacal.
GOOD LUCK

 

The gear ratio wasn't drastically altered but the sprockets were. Front is 17 tooth I think and the rear... Umm I think it's still a 45. I can't guage the speed on my bike since the guage is very inaccurate. So we used my buddy's '79 malibu with a built up, supercharges 350. So I still might be inaccurate but he was at almost 125 behind me. And... ok, 17 tooth front and 44 tooth rear sprocket. Just counted the rear. The carb mods did make a big difference in the feel and power of the bike. Well, with around 50 HP stock anything can make a difference. But with being followed in the malibu, we figured 125. If that is something unusual then I'll have to make a video tape of it.

The petcock is freshly rebuilt with the kit I got from chacal. The shop I have had my bike in said to recheck my valve clearance because the only thing they can think at the moment is that I might have something too tight. I did my own valve adjustment and had never done it before so that wouldn't surprise me.
I definitely would just turn the filter around. I am just changing to a different type.
I am going to change the plugs from D8 to D7 and see what happens and use mid-grade gas.
The carbs are all balanced perfectly and that is checking them using the YICS eliminator.
I guess the "Road Rash" experament sorta continues. I am going to go change the plugs. Hopefully I am not on here in a while asking how to change rings that have melted to the cylinder wall or something.

 

If the filter is going empty that could be the gas cap vent or the petcock's internal plastic screen stopped mostly up. The rich and lean carb pairs could be the center balance screw wasn't correct.

 

Exactly what i was originally thinking... the balance was off between the two sides. I used a local mechanics YICS eliminator and my firends dads merc sticks. The two sides were a little off. It didn't take much to synch them at all so i am not sure that was the problem. They were balanced perfectly. With the merc sticks I could rev and both sides stayed almost perfectly even and dropped evenly with eachother. Well... I am going to try the hotter plugs.I have been doing a lot of reading on plugs. Normally to run with a bigger gap calls for a higher voltage ignition system. I am wondering if, with the richer condition and the bigger jets, if a hotter plug would give me a little better ignition. but I don't want to burn a hole through a piston with that detonation business.
The more I read, the better way to go about it would be to beef up the ignition system. Anybody here ever do that?

 

I have been thinking about using stock ford 4.6 modular coils. I haven't tested them to see what the resistance is in the primary circut or if they'll even fit on 2 and 3 cylenders yet. I thought it would look cool to have the 4 coils on top of the plugs.

***this has not been tested*** so please don't try it with out testing the coils to see if they match the resistance of the old ones times 2.
because you would have to wire 1 and 3 and 2 and 4 together.