Heya all,

Quick question for someone who knows more about these bikes than I do (which is probably everyone and thier brother<g&gt

'74 Sporty (1000CC...guessing XLH?) Dual ingnition. Bought the bike, performed awesomly. Then I changed the plugs...

I'm getting erratic spark to the cylinders, noticed the points are kinda worn (doesn't seem *too* bad), just put a brand new battery and plugs in. Need to replace plugs again due to flooding, I don't see any amount of cleaning getting rid of the instabuildup on 'em.

Bike died under me last week, put a new battery in, ran fine this morning, sat at work today and died again at a friend's house. We ripped into the timing...it looks like it's timed right. But, the only manual I can find is for his '69 Sporty, so what do my points need to be gapped at? His book is saying .020. I'm also getting conflicting answers on what my plugs need to be gapped at, got three different answers at my local dealership ranging anywhere from .025 - .045, so I'm getting more confused as I go.

Also, any suggestions on why the plugs are consistantly getting fouled within minutes? If it was a car I'd say my coil is cooked, but, I know next to squat about bikes and less about HDs.

Sorry this post is disjointed, but, it's late, I'm covered in gas and grease and am not thrilled with this bike at the moment.

Thanks in advance,

 

You say 'erratic spark?' Just what do you mean by that? It sounds to me like your problem may be the carb rather than the spark or timing.
Are the plugs SOOTY BLACK? If so, it is the carb with the problem. You can set the points at .018. Check both lobes and if there is a difference between gap of the two lobes, then split the difference. BTY, they should not differ more than .004. That would mean a worn ignition cam. Rare to happen.
Gap the plugs to .025. Good luck.........................piniongear

 

Heya,

Thanks for the reply,

Yeah, the plugs definatly qualify as "sooty black". I guess I'll see who made the friggin' carb and see what it takes to reset it.
As for the erratic spark, first time I pulled plugs to clean 'em after foul, the rear plug was wet...second time the front plug was wet and the rear was dry as a bone.

Thanks again,

Wolf

 

Hey wolf1477,
It sounds like you may have a carb problem. Pull both plugs and stick a screwdriver into each plug wire boot. Turn the engine over holding screwdrier shaft 1/8 to 3/16 inch away from the cylinder head. If you get a nice fat BLUE spark, then the ignition is OK and the carb is the problem. If the spark is weak and orange, then replace the points and the condenser. Retest the spark jump/color after that.
As for the carb: When I restored my '71 XLCH I bought a new Bendix carb to put on the bike. Fired right up and ran well for two years. All of a sudden it started running rich. Sooty black smoke even came out of both pipes when I gave it the gas and of course the pipes were sooty inside. I had to carry three sets of spark plugs with me everywhere I went because the plugs would foul sooty black (over-rich condition) after riding 25 miles at highway speed. I changed the plugs and it cranked right up and I was good for another 25 miles. I could never determine what happened with that carb, but it must have been some kind of internal leak. That carb has adjustable high and low speed jets, so jet setting was not the problem.
To fix it I dug out the old Mikuni carb (from 1975) that I once had on the bike before the restore and put that on to replace the Bendix. Fired right up and runs like a top ever since! Instant fix. The only downside to giving up the Bendix for me was losing the enclosed throttle cable that I could run with the Bendix. The Mikuni cable blows out in the breeze, but it sure cured the problem of rich fouling of the plugs..............piniongear

 

Awesome thanks,

That exactly describes what's going on here, last night even had blowback thru the carb (timing was off also) but it's spitting black smoke (and some flames) on the start attempts and ever since I bought it it seemed to be running rich (to me). Guy I bought it from just had a new carb put on last summer so I'm going to check into getting a warranty replacement, but, if they don't want to swap then I'll just buy a new one and stop the nightmare. How much differnet is it to set a bike carb than say a Edelbrock racing carb? Much harder/easier? I'm new to HD, but, been building small block S10s forever it seems.

On another note, just picked up a new set of points and condenser, but, now I'm being told I have to have a special tool to do this? Also noticed on the new points the fibre ledge/lever/whatever the heck it's called, is a touch shorter than what's on it now...

As you can tell I've never worked with points before so I'm more'n a little nervous that I'm going to screw this thing up worse than ever, but, our local HD shop is a PITA and the custom shops want 3 arms and 4 legs to even look at it.

Thanks again, appreciate the help,

Wolf

 

All it should take is a screwdriver and a feeler gage to install those points. I certainly have never heard of any special tool needed for this.
As to the size of the fiber piece being a bit shorter than what is on the bike now, that is only a difference in manufacturers I am sure. That fiber is an insulator and rides against the rotating ignition cam, opening the contact points when it reaches the cam lobe(s). This cam has two lobes on it, one for each cylinder. Check the point gap on both cams. Set one position at .018 gap and then check the gap at the other cam. It should be within .002 plus or minus of .018. Any greater reading indicates a worn cam (rare to happen). I always put in a new condenser with points replacement. I have had only one condenser failure in thirty something years, but I still replace it.........................piniongear

 

Yeah, I got the points and condenser installed (PITA to get them set for a beginner!<g&gt

Still won't run...pops, sputters and blows out thru the air filter. I had no luck messing with the carb and finally broke down and called a new shop in town. $75 - $100 to check my timing job and set the carb. Not too bad considering the money I've blown on parts, beer and tylenol trying to get this thing done<g>

Thanks again,

Wolf

 

That could be money well spent IF it runs good after that Wolf. If the bike starts and runs steady but pops and backfires, that may be the timing is off some. The carb is going to cause the richness with sooty black plugs and tailpipes. As I recall you said this started when you changed the plugs? What brand of carb is on the bike?
The points are difficult to install because things are tight inside the case and the points want to creep when you tighten the base screw. This changes the gap, which also changes the ignition timing to a degree. Too wide a gap equals advanced timing, too small a gap equals retarded timing.
The ignition has a centrifugal advance unit that is located behind the points base plate. This might have some damage to it or a broken spring (unlikely) Mine quit once all of a sudden a few years back. Turns out that the main center bolt that holds the cam and advance unit had broken right where the threads stopped. That is the weak point, but I have never heard of anyone having this happen, although a fellow I know has a lot of contact with Sportsters and he told me it is fairly commom. This bolt goes into #2 camshaft (the rear cylinder intake cam)
I hope your shop can get the job done for that price and you are soon riding.......................piniongear

 

Heya,

Yeah, I finally figured the trick to adjusting the points gap without hosing things up too much, when it was fully tightened down it was a snug .018 on the feeler. And since I had everything apart I got curious to see what's behind door number one (the timing plate) and the springs seem fine, I opened the mech there and it snapped back into place nicely so I'm hoping everything's alright there.

Honestly I think the hardest part was getting the wires for the condenser and main connected to the points bracket. When I pulled the cover off and removed the set screw the whole dang mess blew apart so I had not a clue on where the wires were supposed to go (thank you google!).

Scariest part was right after I got the points and everything else in, I cleaned the plugs (I'll be dipped if I'm gonna ruin *another* new set of plugs figuring out the timing<g&gt, threw 'em in, hit the starter and BAM...she ran for about 25 seconds...then wheezed to a halt. After that no mattter what I did to the carb seemed to matter...which is when I called Doc's (is it just me or does every town have a Harley shop called Doc's?) to get an estimate on setting everything where it needs to be.

Oh, yeah, the carb seems to be along the lines of an OEM replacement, I don't see a name on it anywhere, but, it does have a crooked stamp starting with "10" (I can't remember the rest off the top of my head), supposedly this was a new carb last summer...I'm seriously starting to have my doubts. I'm thinkin the guy that did it just threw a rebuild kit at it and called it new, so I guess I know what I'll be doing in the off season...buying an aftermarket carb.

At any rate, thanks a ton for the help and if nothing else...I learned how to put in new points...so this wasn't a completely pointless adventure<g>

If you happen to think of anything else lemme know,

Thanks,

Wolf

 

Haven't seen anyone suggesting adjusting the pushrods. The solid lifters do tend to get outta whack, and can make starting/running a PITA experience.