Author Topic: Black powdery sooty plugs (Read 5303 times)

Chuck Hahn · « **on:** January 26, 2014, 04:29:56 PM »

I had the problem of it running real rich and black smoke coming out the exhaust. someone said to poke out the air holes that lead to the emulsion tube and that took the smoking away.

But still have the plugs getting a powdery black soot on them. Heres what i have done so far::

Set the timing and set then points gap per the manual.

Reverified the float hts was at 14.5 MM and it was...then went to the other setting listed which was 12.5 and the soot reappears at either float ht setting.

I have verified the numbers on the jets and its stock jetting per the factory service manual chart.

I have moved the clip up to lower the needle and no change.

I have even ran it without the air cleaner paper element thinking it may be a problem..and I have opened and closed the choke a dozen times and they are not hung up either. Even remeasured the distance between the end of the accelerator pump and the tab that pushes it and its set correctly. I have went step by step thru the entire carb section of the manual.

I have turned the bottom screws all the way in and as far out as 3 turns and nothing. Even tried the "highest idle" per the service manual instructions and I really didnt notice any RPM changes. Right now the bottom screws are all the way in and it runs, idles, and pulls just fine.

I am a bit confused as to what exactly the bottom screws control. Is it air, fuel, or a air / fuel mixture its metering?? I have dipped these carbs twice for a full 24 hrs each time in new Berrymans too. New orings all the way around. I am open to any and all suggestions as to what the helllll is going on because i am out of ideas.
Could weak condensors be part of the problem ( weak spark maybe )

Chuck Hahn · « **Reply #1 on:** January 26, 2014, 06:19:14 PM »

I should add that I have taken the compressor and blew air into the two round inlets in the bellmouth of the carbs and air comes out the needle jet area very fast. And I have plugged the little hole at the back bottom that the screw points go in to and blown air down the hole the bottom screws go in and its all clear in that passage way as well..best i can tell.

Seems to me all the air passages at the front intake side of the carbs are open and allow a lot of air to go thru them. Are these two ports what supply air to the mixture? If so, I dont think they are blocked.

Sorry if I am rambling but I am trying to understand the air supply flow and why it seems its not getting the right mixture. I obviously have plenty of gas but no air..is that basically whats going on???

joesmotos · « **Reply #2 on:** January 27, 2014, 08:17:01 AM »

It might not really even be a carburetor issue...sometimes the spark plugs arent getting enough voltage to work properly..cant keep the plugs clean...another thing i have seen is the exhaust system has a restriction of some kind,whether it be mashed on the bottom(like someone ran over a speed bump and collapsed the pipe..or,the baffle wont let enough flow past,it chokes of the exhaust and makes the bike foul plugs...or...gasoline in the engine oil,when it gets hot the fumes of the gas gets by the piston rings and fouls plugs..

just a couple suggestions for other things to consider

Chuck Hahn · « **Reply #3 on:** January 27, 2014, 02:03:28 PM »

Joesmoto..thanks for the response. One thing I am OCD about is making sure the petcock is off when I get off the bike. I have several Suzuki GS bikes withn the vacuum operated petcocks and them seeping gas to the oi,.is a VERY common problem. I will take the cap off and give it a good whiff though..one can never be 100% sure.

As for the weal spark..thats one of my concerns. The bike can still run with weak condensors and have a weak spark..as I understand it anyways. Is this correct?

As for the exhaust..its like new. Nice clean headers and a like new muffler that I got off ebay. The original was indeed rusted thru real bad and it smokes then AND fouled the plugs. But since I poked the holes in the carbs real good as suggested the smoking went away, but the fouling of the plugs is persist.

I will,have to read and see if theres a check proceedure for the and I think new condensors may also be in order.

LesterPiglet · « **Reply #4 on:** January 27, 2014, 02:19:37 PM »

You are of course using the correct plugs?

joesmotos · « **Reply #5 on:** January 27, 2014, 03:31:11 PM »

An easy way to check might be to just get a fully charged battery and run 12v directly to the power leads of the ignition coils...basically bypass the wiring harness..in the past(and its been a while )when i did that,and got it fired up,you could literally stand there and listen as the bikes idling RPM just started going up and up as it cleaned the plugs off all by itself,to the point where you had to turn down the idle cause it went up so much..

Chuck Hahn · « **Reply #6 on:** January 27, 2014, 04:47:40 PM »

Yes the right plugs per the manual..D8EA or something like that if i remember right. I checked them with what the manual states and they were a match.

Will try the direct power to the coils thing too. So basically hook a hot wire from the battery to the leads on the coils...and then I can ride it like that with clean plugs to see if they get sooty again. I have a Central Pneumatics cleaner that uses the grit to sand blast the plugs. just hooks to the air line and blasts them super clean in seconds.

joesmotos · « **Reply #7 on:** January 27, 2014, 05:15:27 PM »

Well actually you can just do it with it sitting there...just unhook the leads to the power side of the coil and hook your battery to them...leave the regular battery therein place to get it running(electric starting)..course im lazy so thats how i did it ha ha

Chuck Hahn · « **Reply #8 on:** January 27, 2014, 05:22:43 PM »

Are they they shielded female end that I unplug and hook the wires to the male ends going into the coils? Arent the hot sides the shielded sides?? Wrap them up with tape. I would like to actually ride it the same trip ive taken all too many times to see if the plugs resoot again. If they dont, then we have the problem..low power to the coils. But then..what to check to see why thats happening?? And its a new battery and its been kept on a tender.

joesmotos · « **Reply #9 on:** January 27, 2014, 06:17:58 PM »

Im pretty sure theyre shielded yes,like male/female ends...up under the gas tank ,coming out of the coils..1 power wire per coil...

Dont want to get to far ahead of myself here,im not claiming this is the problem...just making suggestions of things to look for..

You might want to do a search in here regarding youre issue and see what pops up,theres tons of info available

But usually its some sort of resistance in the factory wiring dropping the voltage down..like crap connectors,switches,etc etc

Im pretty sure theres a thread somewhere on this site about wiring in a relay to the coils to get full battery power..

THis sort of thing wouldnt just be relegated to the Automatic,any of the 750s could have this issue.

If you have a voltmeter,you can just take the positive (red) probe and stick it in on of the power wires to the coil and see what the voltage is with the key turned on..

Chuck Hahn · « **Reply #10 on:** January 27, 2014, 06:22:23 PM »

To do that. dont the points also need to be kept open? Im not all that with electrical but i do know they ( coils ) fire when they open. Maybe put a piece of paper between them??

TwoTired · « **Reply #11 on:** January 27, 2014, 06:28:19 PM »

Have you verified the accelerator pump circuits aren't leaking?

Chuck Hahn · « **Reply #12 on:** January 27, 2014, 06:30:39 PM »

I have only verified that the gap between the top of the stem and the lever from the throttle linkage is correct..so how would i check to see if they are leaking bfuel into the carbs??

TwoTired · « **Reply #13 on:** January 27, 2014, 09:51:17 PM »

The pump has two check valves. If the outflow valve leaks, it will spit fuel into the carb mouths.

joesmotos · « **Reply #14 on:** January 27, 2014, 10:35:56 PM »

Im only talking about measuring the voltage at the coils..with a meter...dont worry about the points....if you pull the fuel tank off,you will see the wires going to the coils...two wires come out of each coil....one is the 12v that powers them(or should be 12v if its getting enough juice)...

All you have to do is hook the red meter lead to the power feed wire and the black lead to a good ground..and turn on the ignition key and read the voltage.Thats it..

You dont have to spin the engine over at all...youre just checking to see what the voltage is at the coils.

If its low and the battery in the bike is a known good one,then somewhere in the wiring is a restriction of current flow..
Thats why some guys just wire in a relay..

Low voltage=weak spark at plug=sooty plugs(assuming carbs are ok)

So...if you check the voltage directly at the battery posts..then check it at the coils..and theres a difference...something is reducing the voltage in the wiring..

joesmotos · « **Reply #15 on:** January 27, 2014, 10:38:20 PM »

OH yeah i forgot to mention...when you cleaned the carbs,did you actually remove the emulsion tubes and see if the little holes in them were clear?

If theyre blocked that will definately make it run rich..

Chuck Hahn · « **Reply #16 on:** January 28, 2014, 04:05:41 AM »

I removed everything, 24 hr dipped the bodies AND all the parts..then used a bread tie to poke all the holes. Once poked, I rinsed them with carb spray and then lots of air from the compressor. Same processes im use on all the Suzukis and i never have a problem with those carbs. But this Honda has got me stumped because I am 99.999% sure the crabs are as clean as they will ever be at this point.

TwoTired · « **Reply #17 on:** January 28, 2014, 11:00:01 AM »

Quote from: Chuck Hahn on January 28, 2014, 04:05:41 AM

I removed everything, 24 hr dipped the bodies AND all the parts..then used a bread tie to poke all the holes. Once poked, I rinsed them with carb spray and then lots of air from the compressor.

These are PD style carbs, aren't they? Did you yank out the pilot jets and clean them? What is the diameter of the "bread tie" tool you used? If more than 0.016", this will enlarge the pilot jet fuel orifices. Such damage will cause the machine to run richer.
If I recall, you also mentioned the pilot screws had little to no effect. If the pilot jets are still clogged, this is the exact behavior I would expect.

You soaked the accelerator pump diaphragm in carb cleaner? Carb cleaners are seldom agreeable with rubber and plastic parts.
With most carbs, you have to "prove" that each small passageway can flow fluid when disassembled. With pump carbs you also have to "prove" the check valves seal in one direction and flow in the opposite direction.

Imo, if the plugs are sooty, you certainly have enough spark to fire a mixture, but not enough oxygen to complete the fuel burn.

If you peruse enough threads regarding carb cleaning, you'll find it took quite a few 3rd or 5th tries to actually get the all the carb circuits clean, even though the poster was certain that the carbs were completely clean in their very first post. So, don't overlook the possibility that you missed something unique to these carbs.

Are each cylinder's spark plug deposit patterns the same as all the others? I use this indicator to tell me if the carbs are delivering equally, or if one carb is operating differently.

joesmotos · « **Reply #18 on:** January 28, 2014, 02:12:02 PM »

Yeah i forgot..arent those pilot jets pressed into the body of the carburetor?

THe only way i ever got them out to clean them was to get my heat gun and warm up the body of the carb while i grabbed the jet as far down as i could go with some small vice grips and OH SO GENTLY start twisting and turning and pulling till they came out...not for the meek of heart...

They do come out tho..you gotta be real patient and take your time no doubt..

I agree tho that if whatever you used to poke thru them was to big it basically made the jet a larger size..

Chuck Hahn · « **Reply #19 on:** January 28, 2014, 05:30:34 PM »

None of the rubber parts..such as the accelerator pump was soaked. The accel pump was actually replaced because when i tore them down the diaphram was as hard as plastic and had no flex what so ever to it

And yes, the pilot jets are plugged in right next to the emulsion tube and the main jet. I simply gripped the top with pliers and a twist and pull motion and they came right out.

As for what i poke what with..the emulsion tube got poked withg a regular old bread tie..it has big holes. the pilot jets small inner hole was poked with a wire from a wooden handled wire brush and it wasnt "jammed and ham fisted thru" like a rookie would do...I got a little bit more common sense than to do that.i have taken great care to be sure that they werent abused when poking them..trust me on that issue. I am leaning more and more toward an electrical issue not delivering a hot enough spark..and of course i will check the accel pump for leakage as was suggested. I am looking for some tiny rubber caps that I can slip over the tips inside the carb throats and thus assure they arent allowing the vacuum from the carbs to be sipping fuel from them..which i can full conceed and understand the theory behind it being suggested.

Chuck Hahn · « **Reply #20 on:** January 28, 2014, 05:52:41 PM »

Can I check each pump nozzle in the throats by starting the bike with the airbox off and stick my finger in front of them to see if it gets gas splatterings on it? Do you think there would be a proper flow that way to see if they are sipping fuel???

Looking for suggestions on how to test for fuel wetness at the nozzles when its running..follow my thoughts here??

joesmotos · « **Reply #21 on:** January 28, 2014, 07:03:35 PM »

I admit to being ham fisted on more than one occasion in the beginning ha ha

Sounds like you have a good grip on things..i dont know about the accelerator pump stuff,sorry

If i think of anything else i will post it..

Chuck Hahn · « **Reply #22 on:** January 28, 2014, 07:35:47 PM »

I think everyone has had that newbie heavy hand not knowing whats up. But ive done literally dozens and dozens of sets of Yammy and Suzuki carbs. Thbis Honda is my first big Honda experience and even though I am very very confident in my cleaning ability doesnt mean I know everything about these carbs nor the bike itself, for that matter.

I will for sure need to figure out of the accellerator pump system is leaking and be sure that been eliminated. Once thats done, the next thing would be to go thru probably every connector in the harness and all the switches to be sure they are spotless and making full conductivity. Its gonna be a long day this weekend doing all that but its gotta be done I guess.

joesmotos · « **Reply #23 on:** January 29, 2014, 08:47:06 AM »

Another thing i thought of...once,when working in the ole Honda dealer in the late 70's...i had this CB750 that would start up and idle fine,even rev up sounding pretty normal,but you would get on it and put it under a load and it just wouldnt go..after piddling with it and trying different things i finally ended up replacing the spark plug caps and viola,it revved out.To much resistance in those caps..never had one do that to me since then.

Lets see..what else..had a Kawasaki that had O rings that fit around the needle jet(emmulsifier tube) that had degraded to the point where fuel was leaking by them making the bike run to rich..basically were there to seal against the boss they screwed into..

As far as your condensers go,usually when a condenser is going bad theres alot of sparking at the points,when they do give up,theres no spark at all..

You pretty sure the ignition advancer is actually advancing the timing?Like,with a strobe light on it you can see the timing advance on the marks?Seen those stick too,bikes runs like..well you know.

Chuck Hahn · « **Reply #24 on:** January 29, 2014, 03:35:15 PM »

Yup...checked that when i set the points and the timing. Thanks for the tips though. Anything else anyone can think of I am all ears. next available time I will have to putter with it will be Saturday.

News:

Author Topic: Black powdery sooty plugs (Read 5303 times)