Carbs drive me NUTS!!!!

[johnboi71]

I am just wanting to vent at the moment! I have been working on my bike since friday when I got my new coils from MikesXS. They were a snap to put on my Special But when I started it up, #1 wasn't getting the pipe hot and it was running like crud of course.
I should say that it was running on all 4 (I think) before the swap. I had a low end stumble, and have been through the carbs a dozen times since last year, and just wanted some fresh coils and wires. I did bypass the Ballast resistor also.
Anyway, it wasn't firing on #1 so I pulled the plug to check for spark and it was good. HMMMM, drop the float bowl and there is fuel in it, WTF? I removed the octopus a couple of years ago and have it set up so either petcock will feed all 4 carbs. Check for kinked fuel line-nope. Pull the tank and make sure my wiring was ok to the coils and flipped the tank around so I could try and troubleshoot the carb.
Fire it up and now 1 & 2 are not goingWTF!!Pull the carbs in preperation for yet another teardown At this point sweat is dripping from my forehead and I need a break. My buddy calls and we go for a short ride on the HD's to clear the head.
Get home a couple hours later and pull the bowls . Checked to make sure the floats are even and the needles seem to seat fine. I haven't been leaking fuel anywhere, so I move on to the jets. Pull all 12 and they are all clear. Blow out the passages again and all seems ok so I reassemble and put it back on the bike, hooked everthing up and fired it up. Firing on all 4 again and seems to rev good in nuetral. Take it for a test spin and it is sputtering worse than before from 1000-3000rpm.
Come search the forum again after trying to adjust some of it out with the mixture screws without success. Everthing seems to point to my primary circuit. Go to the Parts store and get another can of carb claener and a set of iridium plugs. Put the plugs in and take the carbs off again today and blow out the passages again. Nothing seemed blocked. This time I take out my emulsion tubes also and they are clean as a whistle. Reassmble it all AGAIN after changing the float level from 24 to 26mm. Back on the bike and fire it up. Now #4 is cold!!! Check for spark and it looks strong. Pull the carbs again-lord I wish I had pod filters- and open up #4. blow out the passages again and back on the bike- #4 still cold
Screw it!!t is time for a break. Maybe I'll get back at it next weekend. It bums me out I couldn't get it running friday, I was hoping to make it to DennyZ for the Friday night BS session before the rally kicked off. Instead I have been working on this PITA for the better part of three days and don't feel as if I've done a damn thing! I thought of trying to get to DennyZ on it Friday and have the great gurus help me, but I didn't want to end up stuck on the side of the freeway at night. Eventually I will get tis thing running good at all RPMs and all will be good for a while. Then it will be time to start doing some mods. I want it to run right first.
I guess I'll just ride the Harley for the rest of this year and just keep trying to get my XS dialed in when I feel like dealing with it again. I am going crazy trying to get these carbs to work when I should be riding. Maybe the XS stays down till summer is over and I have more time to screw with it. All I can say is if I didn't have my HD to ride, I wouldn't be riding this year at all! The Harley may have been expensive, but at least I can ride it.

[Crazcnuk]

Heh, I know the feeling, intimately!

Just a couple things. The problem is with 1 or 4, and both are fed by the same coil. Have you double checked that the coil wires, to that coil are making a good connection, not corroded, that sort of thing? I doubt it is that, but never hurts to check.

Funny part is that both 1&4 fire at the same time(s), so you would think you would lose both, not one at a time. However, we were discussing tis in another thread, and since the coil fires both wires at the same time, if one or the other has a loose connection, would ALL the power go to the one that has a good connection?

It's VERY hard to tell if you have GOOD spark, just by looking at the plug.

Also, when I put my Mikes coils on, I mounted them to the stock mounts, so they are 90deg over, and the one connector, on each coil is very close to the frame, so bent mine, gently, away, just to make sure they wouldn't arc to the frame.

I would think if it was shorting, though, you would lose both 1&4, not one or the other.

Personally, once I have done all that you said, I take the bike for a ride. I find that some of these problems work themselves out a few miles on the road. Just don't do it when you have to be somewhere!

[thewiz]

I just put on some MikesXS coils ....

and I had something like that happen to me. I had other carb problems like needle clip position wrong and finally diaphrams that weren't sealing up .... BUT ... back to the coils

You might have noticed that on the original coils the 'eyes' that the mounting bolts go through have a raised brass nub on either side of each coil's mounting eye. Presumably those brass nubs are for an external ground. The Mikes coils however do NOT have a nub ... in fact they're actually recessed!! I then discovered with a test light that my coil mounting bolts were not a ground. Soooo ... I got a piece of metal tubing that made the bolt fit snugly inside the coil and mouting bracket on the frame and also put a little spacer on one side to make the coil touch the bracket solidly. Everything began to work correctly then ....??? I actually intend to go back and put brass spacers on both sides of each coil's mounting eye to make up for the recesses on the Mikes coils

[blue giant]

Is the resistor in or out of the loop based on the resistance of the Mikes XS coils?

JAT

Paul

[bikerphil]

ballast

By-pass (remove) the ballast when using Mikes XS coils.

[TopCatGr58]

Re: I just put on some MikesXS coils ....

Originally posted by thewiz
Presumably those brass nubs are for an external ground. The Mikes coils however do NOT have a nub ... in fact they're actually recessed!! I then discovered with a test light that my coil mounting bolts were not a ground. Soooo ... I got a piece of metal tubing that made the bolt fit snugly inside the coil and mouting bracket on the frame and also put a little spacer on one side to make the coil touch the bracket solidly. Everything began to work correctly then ....???

Hey Wiz,

The mounts for the MikesXS coils are just mounts. The only ground needed IS the (-) terminal connector, as well as the (+) for the power lead. Like you mentioned, they are a closer fit, and so perhaps one of the actual wire lead connectors was partially contacting the frame, which would interfere with the triggering signal for the coils.

It was reported by an Xsive that he was having ignition problems on 1 and 3 cylinders, which are not shared with fuel supplies as well as the common coils or PU coils. Turned out that he was NOT getting enough voltage TO the coils, and so there was just enough power to fire 1 plug, but not enough to travel thru the engine and back up to the other matching plug for that coil!!!

John, many of US have felt your pain, sometimes is something simple although unexpected...like a pilot jet falling out!!
So....back to basics, air, fuel, spark. The symptoms are jumping from #1 to 1&2, and then to 4? This does sound more like problems with fuel/carbs than electrical. You've got NEW ignition coils, caps, plugs. You bypassed the Resistor(Paul, it's OUT of the loop with the MikesXS coils), but you could check to be sure you're getting the 12 volts to the (+) of the coils. And checking the PU coils wouldn't hurt. Then, after confirming that the spark and control for it is working right, then move on.

Have you verified no vacuum leaks? Have you ever taken the intake boots off? The rubber on the mating surface can get hardened and crack. Also the intake boot Synch Ports....the rubber caps on them can do the same thing....I think it was our Guru "JOHN" that had trouble tuning his until he replace the caps which solved the intermittent vac. leaks!

Then, finally the carbs. You've cleaned them enumerable times, verifying that the Pilot circuit is clear. You've sprayed cleaner thru the Pilot Jet tower, and seen it flow out from the Pilot SCREW hole on the front, then capped it off, and seen it flow out the little holes in the top of the engine side of the carb throat where the butterflies contact when closing. And I'm sure you don't have any Pilot Jet SCREW tips stuck in the carbs?? And you've also verified that the vacuum slides and diaphragms are in good shape, no pinholes??

Yeah, having to ride ONLY your Harley would have me upset, too!
T.C.

[johnboi71]

Been out of town for work and haven't done anything else yet. I hope to take a look on Sunday. I will check the pickups after I triple check for vacuum leaks. The boots are cracked on the outside, but they looked good inside last year. Haven't looked at the inside this year. I think I will pull all the plugs and check for somewhat equal spark, then try and determine if I am getting fuel into all the cylinders. If those check out then onto the pickup wires and a doublecheck of the electricil system. I need to get some long fuel line so I can set up my tank better. Don't want it to fall off again and get another dent/scrape.
I also have to troubleshoot the charging system on my Ramcharger, replace the speedo gear on My 67 Dodge D200, GO FOR A RIDE!, and get ready to start my vacation Thursday. I just hope the weather is good so I can fix this stuff so I can move down the list-leaking skylight, rebuild the porch, fix the dry rot in my eaves, the list goes on......A man has to have priorities, and my wheels come first

[johnboi71]

Well I spent the better part of this afternoon checking things out. The boots are cracked on the outside but smooth as a babies butt on the inside. No apparent vacuum leaks anywhere else that I can find. Saw spray flowing out the little holes in the bore when I sprayed. The floats are set at 25mm. put it back on, hooked up the gas and started it. still cold on #4. Pull the plug and it smells like gas. Then I set the plug against the block and saw some spark when Ihit the starter. Said WTF and threw in the old plug in place of the nice Iridium I just pulled out. It started (was running real rough as I had messed with the sync and was hoping to be able to reset it while running) After a short warm up I managed to get #4 to steam when I sprayed it FINALLY!! I shut it down as it was running real bad and pulled the carbs to bench sync ( bread tie method) and put them back on. Went to start the bike and it wouldn't start. Tank low on fuel-yep. Go get gas to fill it up some more. Get home, fill her up and hit the starter button-no go. At this point I am pulling my hair out.
Time to pull out the multimeter. Negative jammed into the braid of the negative cable. and positive to the dual connector feeding the positive side of the coils. Turn on the switch and key I read 10.9 volts, hit the starter and it drops to 9 volts. I remember TC saying these coils need 12vdc to fire right.
The battery is on the charger right now, Hope this thing will fire up again after a full charge

[Ivan]

If I am not mistaken the TCI quits working at 10.5V. I'd bet a night on the trickle charger would at least get her to fire.

[scalded dog]

johnboi, you may have already checked, but make sure that none of the gas overflow gets into your oil. Just mentioned it, as a precaution. Later 'Dog

[psycoreefer]

May also want to work your way back along that wire checking any connections along the way. You should have checked the voltage at the battery as well, could be the battery was ok but there was enough resistance in the supply wire to drop your voltage to low. I read somewhere that a guy was recommending everyone with an older bike bypass that coil + wire and run a new direct supply wire directly from the battery. Claimed it made a significant improvement.

[randy]

psycoreefer;

bypass that coil + wire and run a new direct supply wire directly from the battery.

Of what coil+wire do you speak?

[psycoreefer]

let me be as clear as mud here....

The "positive" wire that supplies the coils with current when the ignition is on. I'm sure you'll correct me if I'm wrong but I think there is only one hot +12V wire going to the coils right? Then it splits right at the coils to feed both.

Also I suppose I should say that you shouldn't just hook a wire from your battery directly to the coil, (although you could do that temporarily to see if there is any improvement) you'll want to use a relay switched by the original feed wire so your coils only have power when the ignition is "on".

When I get home I can take a peek at the wiring diagram and be more specific about which wires should be hooked to which poles on a standard relay.

[randy]

Instead of adding more possible points of failure with switches, relays, new feeds, etc., why not just make sure the OEM wiring and connectors are intact, clean and tight?

Will also help future troubleshooting if the wiring is maintained as close as possible to the original schematic. How many of us have spent time scratching our heads over some hooey wiring fiasco from a P.O.?

[psycoreefer]

May also want to work your way back along that wire checking any connections along the way. You should have checked the voltage at the battery as well, could be the battery was ok but there was enough resistance in the supply wire to drop your voltage to low

I did suggest he check and clean the "factory" wiring first.

I have not done this mod to my own bike but I have read about it. I would only consider it for:
A. Testing purposes - its relativly easy to run a wire from battery positive to the coils.
B. If I found that cleaning the connections on the factory wire didn't increase the measured voltage to close to what I measure at the battery.

Instead of adding more possible points of failure with switches, relays, new feeds, etc., why not just make sure the OEM wiring and connectors are intact, clean and tight?

I doubt adding a single automotive relay is going to significantly increase the MTTF of the system.