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Discussion Starter · #1 ·
I'm trying to get my ironhead started for the first time in a while.

I got it as a frame with engine mounted. I rebuilt it as a complete bike from there. '74 sportster with electric start, points ignition. Engine was running when previous owner took the bike apart to do stuff, engine was not removed from frame.

I put the puzzle together to make it a total roller. I wired it up using Easyrider diagram like this (minus the horn stuff).


I first made sure oil was going to and from the engine. Turned it over a few times with the plug wires off to get the oil flowing. Good to go there.

Then I tried to start and fuel dribbles out the velocity stack. So I figure there's a carb issue but I decide to start from scratch before I go there. I adjusted the valve tappets like this video...
It was pretty much right on already but I went through the motions as in the video.

Then I went to check timing and points gap as in this video...

This is where I found my first bona fide problem. The points gap was right on at .018 on the wide lobe. But on the narrow lobe it was much much less at .010 or so. I thought they were supposed to be the same. Also, the contacts don't seem to exactly line up.

Now, I had checked the gap previously and it must have been on the wide lobe because it was right on and I thought all was good. So I've stopped here to try and figure out what to do next.

I guess my question is in two parts, but I need to take them in order. First, what is up with my points?

Once I figure that out, I can move on to the carb flooding issues.

Any help is certainly appreciated. I'm anxious to get to riding. I've been elbows deep into getting old trucks to run from nothing. But this is deeper than I've been on any previous bike I've had and my first American bike. Thanks!
 

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The cam your points actually ride on is not seated correctly, or the advance weight tower has an obstruction under the base. Remove the points base plate & the tower screws to expose your advance unit. Remove the bolt that holds the advance unit & remove. check the unit for defects & clean.. Good time to service your advance unit, remove weights & springs & inspect for wear. apply a dab of heave high temp grease to the 2 posts that the weights ride on. Then reinstall unit. You will notice a slot & a pin in the center of the opening. Make shure when you reinstall the unit that they line up or they will not seat. install the points cam & enshure the anchor bolt is not bent.use a dab of never sieze to the threads & install. before you tighten the bolt , crank the engine to see if it is rotating uniformly. if not, adjust by hand & repeat when its correct, tighten the bolt."DO NOT CRANK IT DOWN LIKE A HEAD BOLT, IT WILL SNAP" Tighten with your hand on the ratchet head & snug it down. reinstall points, gap & ride.... Your on your own with the carb!!!
 

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Discussion Starter · #4 ·
You can tap the point lobe with a punch and check both gaps...

Keep taking a light hit at it and checks until they have the same gap...

Do not get "John Henry" with the hammer.....
I will try that and report back tomorrow.

Any tips for the Keihin carb? Was reported by good friend to be off "running bike", no reason to believe otherwise. I adjusted the mixture screw to 1 1/2 turns out and cracked the idle speed open barely. Fuel drips out of the velocity stack and overflow when starting.
 

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Discussion Starter · #5 ·
The cam your points actually ride on is not seated correctly, or the advance weight tower has an obstruction under the base. Remove the points base plate & the tower screws to expose your advance unit. Remove the bolt that holds the advance unit & remove. check the unit for defects & clean.. Good time to service your advance unit, remove weights & springs & inspect for wear. apply a dab of heave high temp grease to the 2 posts that the weights ride on. Then reinstall unit. You will notice a slot & a pin in the center of the opening. Make shure when you reinstall the unit that they line up or they will not seat. install the points cam & enshure the anchor bolt is not bent.use a dab of never sieze to the threads & install. before you tighten the bolt , crank the engine to see if it is rotating uniformly. if not, adjust by hand & repeat when its correct, tighten the bolt."DO NOT CRANK IT DOWN LIKE A HEAD BOLT, IT WILL SNAP" Tighten with your hand on the ratchet head & snug it down. reinstall points, gap & ride.... Your on your own with the carb!!!
I will try that. Thanks.
 

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Discussion Starter · #7 ·
Exactly as Dragstews said, tap on it lightly and creep up on it 'till it's equal.

Jerry
Rhode Island
I'm going to try that first. If that doesn't work, I'll take it all apart and put it back together.

Still looking for tips on tuning the Keihin.

Thanks all!
 

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The best tip for tuning Keihin is replacing it. A 74 came stock with a Bendix, but that isnt much of an improvement. A modern CV from a big twin works real good, but you have to use an adapter to make it fit. Of course you can drop some coin on a Super E, the one on my 74 works great.
 

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Discussion Starter · #9 ·
The best tip for tuning Keihin is replacing it. A 74 came stock with a Bendix, but that isnt much of an improvement. A modern CV from a big twin works real good, but you have to use an adapter to make it fit. Of course you can drop some coin on a Super E, the one on my 74 works great.
Let's assume I'm keeping the current carb for now. I'm going to rebuild it. And talk to the local long beard to make sure it's jetted correctly.
 

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Discussion Starter · #10 ·
yu can adjust the cam by loosening the nut and pushing the cam with ur finger towrd the too wide side ,, old school trick
I took all that apart today. It makes it a little easier to understand taking it apart and putting it back together. But anyway, the contacts on the points aren't really lined up well. So for cheap peace of mind I'm going to change it for a new set of points and condenser and time it and set the advance from scratch.

That and doing the carb will hopefully have me going. All the other ignition stuff is new. I can get points and condenser today. The carb kit will take a day or two to get here. More soon...
 

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Several years ago a friend was having the same problem, told him to tap the points cam to even it out and he said, ya right...now will ya tell me how to fix it, you should have seen his face, lol.
Like slimm said, take it apart and lube it, inspect to make sure everything is moving properly, reassemble and check again and if need be, TAP the cam gently untill it is the same on both lobes and you should be good to go. If ya put a new set and condencer in, ya can keep the old set as a back up.
On your carb, these old intakes are bad about leaking. Can't tell ya how many times I've seen some one chase a carb tune and all it was was a leaking seal. I know your not gona like hearing this but....If it were me, I'd get a new set, pull the heads and install. While ya got the heads off ya can inspect the valves and guides, bore and play in the rockers. Your gona get two things from this, one, your gona learn what is involved and learn how it works and 2 your gona have the peace of mind that is is done right. Every time I've seen someone cuss an old ironhead or shovel for that matter the problem has been because someone has half assed something, take your time now and do it right and ride the wheels off of it.
 

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Discussion Starter · #12 ·
Several years ago a friend was having the same problem, told him to tap the points cam to even it out and he said, ya right...now will ya tell me how to fix it, you should have seen his face, lol.
Like slimm said, take it apart and lube it, inspect to make sure everything is moving properly, reassemble and check again and if need be, TAP the cam gently untill it is the same on both lobes and you should be good to go. If ya put a new set and condencer in, ya can keep the old set as a back up.
On your carb, these old intakes are bad about leaking. Can't tell ya how many times I've seen some one chase a carb tune and all it was was a leaking seal. I know your not gona like hearing this but....If it were me, I'd get a new set, pull the heads and install. While ya got the heads off ya can inspect the valves and guides, bore and play in the rockers. Your gona get two things from this, one, your gona learn what is involved and learn how it works and 2 your gona have the peace of mind that is is done right. Every time I've seen someone cuss an old ironhead or shovel for that matter the problem has been because someone has half assed something, take your time now and do it right and ride the wheels off of it.
Seems like most everything is half assed on these ironheads. I may wind up going through the heads just because I like to learn how stuff I have works. Seems so much easier to fix stuff when you know how it works.
 

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Discussion Starter · #13 ·
I got new points and condenser today and ordered a rebuild kit for the carb. The carb kit should be here in a couple of days. But today, I installed the new points and condenser and timed it from scratch and set the advance. I did wind up having to do that little trick dragstews described with the punch. Gap is now perfect on both lobes.

I did find the o ring gasket in the carb was ripped in a spot when I took the bowl off to check the float. So it seems like getting a kit for it was a wise decision.

Maybe I'll get it started soon?:D
 

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Nothing wrong with a keihin. Get the Andrews accelerator pump kit for it.

I like keihins. Mostly because I can buy em by the bucketful for $5.00, because nobody else likes them.

An upgrade to the accelrator pump makes em work pretty good, although permanently eliminating the low end lean cough can take a bit of tuning.
 
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