QuestionQUESTION: i just bought this bike so ill tell you what i do know
the bike is a 1999 FXD harley with a 95 ci upgrade by carls speed shop in daytona 575 lift cam ,heads ported and polished ,typhoon carb with a thunderjet ,exhaust with minor baffles(some back pressure-27,000 miles on bike and upgrade was done when it was new
i just brought it home and it coughed anytime i was going thru town(about 40 to 50 mph and just cruising) if i hit the throttle it ran like a bat outa hell-the guy i bought it from says that it does this when its cold and its 55 degrees out today in florida. the drive home was 30 miles and it never stopped during the whole ride unless i ran thru gears hard it ran great then only. never got on the freeway tho-he says its not lean enough-i say its to lean .i know ill have to just fiddle with it but i wanted to hear what your advice is
thx
bob
ANSWER: Pull your spark plugs and let me know what color they are
Mike
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QUESTION: the spark plugs were autolite platinum-the upper elctrode was grayish-the bottom electrode had crude around
it- it looked like a round dirty pyramid around the skinny bottom electrode-they looked like it was time to change and the gaps were large- (incorrect)so i put in a new pair of ngk regular spark plugs-(figured that would fix it) no change(did run good for 40 yards tho)-i adjusted carb 1 flat lean no luck(that was by accident thought i was going rich)then i went back to original spot and then tried 1 then 2 then 3 flats rich-seemed to cough out of pipes then so i figured that ment to rich so i went back to original on the typhoon carb-the carb had a 90 on it with small filter-i put the original air filter assembly on and that didnt change anything either-still runs great under acceleration
but at a constant speed in any gear it coughs thru the carb
(coughs bad enough i can barely ride)i checked the spark plug wires -they read in spec-i tried to read the single fire coil-secondary circuit read infinite and primary read short-that is not what the book says is right-that reads bad-was going to check with another meter
but cant do that till tomorrow- i also found the ground strap to voltage regulater pulled from bottom of it-so its not connected)dont know what that would do-was going to solder it back in tomorrow -put in gas treatment in case it was bad gas-no change-took off gas cap while i was riding in case vent was messed up-still no change. the coil was checked after i was done messing with it-i have it out now trying to verify if its bad or not-i am trying hard to figure this out and i hope all this info helps-i did this since i first talked to you on initial request for help
AnswerYour cough in the motor could be caused by a pushrod being to tight if you have adjustable pushrods or a leaking valve. I would think the coil would be ok, since it runs good when you give it the throttle and only has the problem when you ride a constant speed. Also, check any vaccumn lines going to the carb and make sure they are tight.
Good luck and happy riding
Mike
