1984 FLHTC HARLEY IS running rough after it is started.?

Question

The factory carb was jetted about a 1000 miles ago. It had this popping sound ever since then. So recently the starter solenoid, and the relay was changed. It was put together right, all wires and hoses were checked. And the only thing I could think is coincidently the carb went bad at the same time. When you fire the bike up it runs rough and it dies out. What could it be.

I had after market straight pipes put on at the same time carb was done. It ran fine about a 1000 miles until the starter solenoid started getting worse. So I changed it and the relay, and when I fired it up and took it for a ride about 5 minutes later it started missing really bad and then I had a heck of time trying to keep it form dying out. And it did a couple times. Really I don't now what it is.

Answer 1

First off, you only need to rejet a carb if modifications were done. What type of pipes are on the bike? Popping sounds can be carb or timing. Does the bike get smoother after it warms up? If it does you might want to check the mixture or go up one jet size.

Answer 2

Well running rough...you would think they chnage the plugs after jetting the carb...Personally I probably would not have kept the stock carb (non-cv Keihin) but you gots what you gots....I would start easy-check for fouled plugs if one is fouled most likely an intake leak, also a head gasket, or exhaust leak (but those would be obvious) if they are both fouled then I would look at the carb...but also you said that you had to change the relay (and the solenoid) after a while maybe someone made some mods to the timing for more power (or maybe to correct a fuel, ignition problem)that will give sghort life to the solenoid from extended starting times at worst case the starter too...sounds like you have a very easy problem to solve you just need to spend some time strating from the most recent changes to the the less obvious.

Answer 3

It sounds to me that your bike is running too lean. I highly doubt that the starter solenoid had anything to do with your problem, think about it, the starter is only is used to start the bike. I should tell you that I have never owned or worked on a harley, but have had plenty of experience working on dirt bikes that had carb issues similar to what you describe. I an assuming when they jetted your carb for your new pipes you were given the correct jets so my best guess is that they just need to be set correctly which is a time consuming a somewhat difficult task, do you have a buddy who knows how to do it? If so help and learn how to set it up correctly, efi is much easier to adjust since all you have to do is download the correct map, but on a calibrated bike you will have to adjust the mixture screws correctly. Without help or knowledge a manual may help but its more of an art than a science so you may be out of luck. Best of luck to you.

Answer 4

First of all, the starter stuff would have nothing to do with the carb other than coincidence or something like a hose was knocked off when replacing those parts.

Since the pipes and popping started at the same time, it leads me to think it's still jetted too lean. Not sure what make of carb you have, but if it actually has a true choke and not an enriching curcuit like used on Mikuni, when it's popping, try closing the choke slightly. If it stops popping and runs better, then it's certainly too lean. Using the idle circuit screw to enrich the idle circuit may be enough to fix it.

However, before you go screwing around on things, you need to determine when it runs crappy. At what throttle opening does it pop or run bad? Is it only at small openings, half throttle or wide open? Does it run worse before the engine is warmed up and still on choke, before warmed up off the choke or after the engine is throughly warmed up? Is the poor running consistant Monday through Friday or intermittent? Does it run worse on foggy or raining days and better on dry days? Does it pop out the exhaust or from the air cleaner? On decelleration, accelleration or cold running? When you whack open the throttle?

These are all things you need to determine BEFORE you start making changes or take it to a mechanic. If the mechanic knows what he's doing, he'll ask you the same questions. If he doesn't ask you, better let someone else work on it.

Notice I told you what I THINK it may be, but I also gave you a way to try to narrow it down before tearing into things. There's no way I'd work on your bike without asking you detailed questions. Any one who gives you a quick, steadfast diagnosis without questioning you or riding the bike is one to steer clear of. If you wish to email me with more details after you've ridden it and found what brand of carb it is, feel free.

Answer 5

sounds like you need to look at the last problem you were working on, starter and relay. If it was running fine with the combo of carb and pipes then no reason for it to suddenly run bad. I'd say something loose from putting starter and relay on or maybe there was a short caused on the wiring somewhere while putting those parts on which could cause it to run rough.

Answer 6

Don't mess with a Harley unless you know what you are doing, and it seems to me that you dont know :-) The old man is 23 years old now and deserves being looked aftre properly. Try your local Harley dealer. Drive by (if the motor will hold out that long or better still put it on the back of a trailer so that the expert can hear it when the motor is cold). Seriously though, it's hard to give a diagnostic online but sounds like Tim H has the right idea with that little air leak, whereas Dennis the Menace should go back to his bicycle! Neither a carb or exhaust are electrical, so what is he on about? Have a nice one!

Answer 7

The engine is working too slowly at idle. the foremost probable reason is that the idle velocity adjustment on the carbureter is desperate incorrectly or the idle mixture isn't in basic terms right. Get a Chilton's restoration instruction manual on your motor vehicle from the library and bypass in the process the completed carbureter idle putting technique. till finally now adjusting, as quickly as you have the air purifier got rid of, clean the carbureter with Gumout. Squirt some into the throat of the carbureter with the engine working for a minute and clean the dark deposits from the steel. additionally squirt some into the air vent tube that is going to the inlet bowl. The engine will stumble. Squirt slightly sufficient Gumout in to maintain the engine working. Then do the adjusting in conserving with the Chilton instruction manual.

Answer 8

As for all the other posts. They asked a simple question. Is your bike a Shovelhead or Evo Engine. Your intermediate jet might be to small.
It is popping, because your engine needs more gas.

Are you using Harley spark plugs. If so, take them out and put in Autolites. Put on a K&N Air filter also.

Then go out and get new pipes. Drag pipes make alot of sound. They do nothing for your bike. You can get the same sound out of other pipes.

Answer 9

It sounds as if you have fouled spark plugs. Remove them and look to see if they are black or wet looking. Use as little choke as possible and use the throttle set screw on the hand grip to raise the rpm of the motor when it's warming up and not the choke. Popping sounds can also be a bad ignition coil, but check the plugs first.

Answer 10

I might as well put my two cents in, if the carb was pulled off the bike and the carb seal was not replaced then it could be an intake leak. check and make sure that you don't have an exhaust leak also.

Strange side note check the battery if it's over 3 years old then it could be starting to break down (between the plates)and cause the bike to start popping.