1973 Shovelhead losing power on acceleration

[Faroutfreak]

I have a 1973 HD FLH , one of my Kids friend got on it a few months ago ( without permission , he is 7 yrs old ) he turned the ignition on and left it on , The results were , dead battery , coil had split in 2 . I replaced the coil , Plugs, Points and condenser but for some reason it wants to spit , sputter and lose power when accelerating . I've reset the points to make sure they are at 18 on both lobes as well as the timing and Plugs , it fires right up with no problem . When I go down the road and get on it it sputters and sounds like its fouling the plugs . The Carb is a S&S E . Has anyone got a clue as to what is causing this to happen ,

[Ohio HD]

Did you check the ignition timing after replacing the points?

[westcomb]

Not sure this is your problem? ............ But I have seen lots of junk new just out of the box condensers 

Hard to find a good set of points and condenser anymore!

[harpwrench]

+1 on a new bad condenser

[Hossamania]

Not sure this is your problem? ............ But I have seen lots of junk new just out of the box condensers 

Hard to find a good set of points and condenser anymore!

Definitely something to look at. Also, did you get a new battery? I have found that when they get run completely dead, they do not recover to 100%. Damaged batteries tend to cause weird problems. Have you checked the voltage when the bike is running, both at idle and at about 2000 rpm's?

[tomfiii]

Recheck wire ends connection to wires also.

[Racepres]

If it ran OK previous...You caused a Problem in replacement...The old Condenser is most likely OK...put it back to start with..
Then, Ensure you are timed correctly...not trying to be a Dick...but, lots of folks have timed to the rear cylinder...Check...then Double Check

[76shuvlinoff]

The safest bet is always to go to the last thing you touched and take another look. The condenser is definitely a suspect.

Recheck wire ends connection to wires also.

Yes and maybe check the connections at the dash mounted ignition switch too. Sputtering under acceleration is sometimes due to bad contacts in the switch from years of vibration. Does your switch have a "run" and a "lights" position? whatever you are running it in try the other. Maybe reach down and twist it a little while it is acting up. See if anything changes or if you can recreate it.

[dirtymike]

Has the bike been sitting for a long period of time.

[packrat56]

     FwIw A few years ago I changed a bad  coil for a friend. He bought the coil from a indy shop it took three before
he got a good one. They were the ones with the molded tab and two holes.
Packrat56   

[Racepres]

     FwIw A few years ago I changed a bad  coil for a friend. He bought the coil from a indy shop it took three before
he got a good one. They were the ones with the molded tab and two holes.
Packrat56

Odd, as the Style is OE for older ones...
What was the problem? No spark??
If "weak spark" how the hell did you measure that?
My boys wont hold any wire while I crank a Bike anymore!!!

[packrat56]

     FwIw A few years ago I changed a bad  coil for a friend. He bought the coil from a indy shop it took three before
he got a good one. They were the ones with the molded tab and two holes.
Packrat56

Odd, as the Style is OE for older ones...
What was the problem? No spark??
If "weak spark" how the hell did you measure that?
    They  were dripping tar, all worked for less then ten miles.   
My boys wont hold any wire while I crank a Bike anymore!!!

[Faroutfreak]

Thanks all I was leaning towards the condenser , just was hoping J&P had sent me a good one , Well off to NAPA  for some old Chevy points and a Condenser

[Racepres]

Thanks all I was leaning towards the condenser , just was hoping J&P had sent me a good one , Well off to NAPA  for some old Chevy points and a Condenser

Corvair as I recall...but,  about any Chevy 6 cyl seem to work...

[Texasroo]

I have a 1973 HD FLH , one of my Kids friend got on it a few months ago ( without permission , he is 7 yrs old ) he turned the ignition on and left it on , The results were , dead battery , coil had split in 2 . I replaced the coil , Plugs, Points and condenser but for some reason it wants to spit , sputter and lose power when accelerating . I've reset the points to make sure they are at 18 on both lobes as well as the timing and Plugs , it fires right up with no problem . When I go down the road and get on it it sputters and sounds like its fouling the plugs . The Carb is a S&S E . Has anyone got a clue as to what is causing this to happen ,

From your post ( and I'm brand new on this forum ), it would appear that prior to the " Ignition left on " incident, you hadn't ridden this particular bike. First: Symptoms... 1. Can you ride through the issue ?. Can you slow the roll into throttle and the bike will straighten up and then move through the revs ?  Peg the throttle and it eventually catch up to itself ?  SUGGESTIONS  If the answer to any of these is yes, then it is not a secondary ignition issue. Once ignition starts to break down, it only gets worse. If you don't have compressed air in your garage, then try this old racer's trick. With the bike on the side-stand running and at operating temperature, and the air cleaner housing off, hold the revs to about 2000 rpm and then place your hand over the air-feed side of the carb while simultaneously cracking the throttle WOT. The object is to loosen anything blocking air bleeds / passages in the carb. The trick is to pull your hand off at the right time so that the engine can recover, yet long enough to suck through any dirt, etc.( and not blow your motor up )
Of course this is based on a yes answer to having verified all the basics first ... Battery Voltage, Charging rate / quality, Fuel quality and volume of feed, etc, etc.  Best of luck mate.

[billbuilds]

     While the points plate was off did you check out the condition of your advance unit? The pivots posts need to be lubed every now and then - I've used Marvel Mystery Oil. Check the continuity of the wire going from your points to the coil. Sounds like it might have gotten pretty hot. I agree with others who say make sure your timing is on the mark. Bill

[Tobias]

I agree with checking the ignition components as posted above
but since it's been sitting for a few months it could also be carb related.
Since it seems OK at lower speeds and then balks at higher speeds I would look for something plugging the main jet.

Hope you weren't too hard on the kids for being interested in the shovel.
I would have done that in a heartbeat when I was that age if I thought I would get away with it.

[Hossamania]

One of the kids didn't try to help dad out by filling the gas tank (with who knows what), did they?
Just saying. My kid helped me by filling the lawnmower with the garden hose. Man I was a bit upset (pissed) when I saw him doing it, then just started laughing and explained the proper procedure.   

[76shuvlinoff]

Hoss that's better than when my brothers helped gas up the old man's 68 Chrysler from the mud puddle behind it.  (In a gravel drive).

[farmall]

Blue Streak part numbers any auto store can cross-reference:

DR90X Condenser.

DR2240X Points.

I have two Shovels and one Evo with points so I buy two or three points/condenser sets at a time and keep at least one new advance unit/backing plate combo on the shelf. It's not that they wear quickly, it's that they wear eventually and don't cost much. I stock up on spark plugs too.  I make ignition wires using V8 aftermarket solid wire kits. Be sure to get a kit whose wires fit your coil and have both 90-degree spark plug and correct coil boots since some HDs are fitted with aftermarket coils with male connectors. It's not a lot of money, fewer separate orders, and I don't get bootyraped buying plug wires by the overpriced pair. I keep at least one spare coil.

I don't buy toilet paper by the sheet either. A spare set on the shelf even if you have one Harley is good insurance, and parts prices aren't going down.

Easy way to check spark on single fire Harleys (and wasted-spark Japanese fours) is rubber band both spark plugs together since coil fires pole-to-pole.

I look for excuses to clean carbs since modern fuel is so nasty. (I keep a spare carb too. It was painless to accumulate.) My '82 recently had the same symptoms as the original poster.  Dipped the carb in Pine-Sol and it's good to go. Just blowing out the jets wasn't enough.

Get a set of manifold seals (and one for reserve) and good clamps (I prefer the "aircraft" style but stockers in good shape work fine). Never hurts to replace those while you are there, especially since unbolting the carb can finish off a deteriorated seal or move things enough to make one leak. A

[Hossamania]

Blue Streak part numbers any auto store can cross-reference:

DR90X Condenser.

DR2240X Points.

I have two Shovels and one Evo with points so I buy two or three points/condenser sets at a time and keep at least one new advance unit/backing plate combo on the shelf. It's not that they wear quickly, it's that they wear eventually and don't cost much. I stock up on spark plugs too.  I make ignition wires using V8 aftermarket solid wire kits. Be sure to get a kit whose wires fit your coil and have both 90-degree spark plug and correct coil boots since some HDs are fitted with aftermarket coils with male connectors. It's not a lot of money, fewer separate orders, and I don't get bootyraped buying plug wires by the overpriced pair. I keep at least one spare coil.

I don't buy toilet paper by the sheet either. A spare set on the shelf even if you have one Harley is good insurance, and parts prices aren't going down.

Easy way to check spark on single fire Harleys (and wasted-spark Japanese fours) is rubber band both spark plugs together since coil fires pole-to-pole.

I look for excuses to clean carbs since modern fuel is so nasty. (I keep a spare carb too. It was painless to accumulate.) My '82 recently had the same symptoms as the original poster.  Dipped the carb in Pine-Sol and it's good to go. Just blowing out the jets wasn't enough.

Get a set of manifold seals (and one for reserve) and good clamps (I prefer the "aircraft" style but stockers in good shape work fine). Never hurts to replace those while you are there, especially since unbolting the carb can finish off a deteriorated seal or move things enough to make one leak. A

All good advice. Just bought two sets of plugs for my RoadKing, coincidentally.

[scootersage]

i kinda agree with condenser. with points faster you go less spark available. need to collapse  that field fast.  then again he didn't put his foot on the air cleaner and  move something there did he, little air leak at manifold.

[Hogman]

Been watching this for a bit now, and I'm Hoping it's Not a Coincidence of Issues happening at the Same Time, Like the O/P Stated, he Replaced the Needed Parts etc., BUT What IF he has a Crappy Aftermarket Fuel Filter on it, and THAT is the Rest of the Problem, all Just Coincidental mind you..... I Usually end up Removing them whenever a Bike comes in with issues, AND has one. SOME Folks get Lucky using them, Many, MANY Don't. Just Trying to help, & thinking outside the (Obvious) Box.
Good Luck with getting it up & Running, PROPERLY....... 









ME

[Racepres]

BUT What IF he has a Crappy Aftermarket Fuel Filter on it, and THAT is the Rest of the Problem, all Just Coincidental mind you..... I Usually end up Removing them whenever a Bike comes in with issues, AND has one. SOME Folks get Lucky using them, Many, MANY Don't.   
ME

Any inline filter is suspect and should be removed...I detest them...never Use one...
Good Point

[76shuvlinoff]