1981 Sportster, first Harley project

[Noob2015]

I just purchased a 1981 Sportster Sunday. I got it for 1k and I'm not able to spend a lot of real cash on it. I need advice since this is my first Harley. The rear motor mount is cracked, the rear frame is cracked in all 4 spots above and below the motor mount. I am at work today, but I'll take pictures as soon as I can. My question is, should I tear down everything and weld the motor mount and frame section? Should I weld the frame and replace the motor mount with an OEM or pingel unit? I really can't afford $140 for the motor mount. I found the broken frame section on eBay for $10 and OEM used motor mounts for 30-70. Money is tight, but I know doing it the right way the first time is worth it too. I have been interested in doing a rigid bike as well. I was thinking of doing it with an EVO motor instead of the solid mount ironhead. But since part of the frame is damaged anyway, should I just replace the whole rear section with a hard tail? Any recommendations on who makes a good one that fits right? And inexpensive would help. I have done a rigid frame jap bike before and built the hard tail myself. It was a pain. I'd really rather not go through hand fabbing one again. I'm going to the DMV to do title transfer after work and I have the old battery charging, if all that goes well and title is clear, I'm gonna start by making sure the bike fires up and runs before I tear it apart to repair or replace these broken parts. I was told by the previous owner that this bike has an S&S super B carb, high output generator and coil and that its been bored out to a 1200. If I take good pics of these items, can any of you verify if any of this is true? Sorry to sound so unknowledgeable. I have had 8 bikes in the past, but they've all been jap bikes. Any help and info that anyone can give, would be much appreciated.

[Noob2015]

[Noob2015]

[Noob2015]

[Noob2015]

[Noob2015]

Here's a pic of the last jap bike I did. I feel like I'm asking some probably basic crap about Harleys, but figured if I post my last bike, you guys may take me more seriously. I put all the wiring in a fake oil tank, fabricated the rigid frame by hand, mounted a DNA springer front end and Harley wheel setup. Had to cut the neck down to fit it. Modified a stock honda aero gas tank and nearly every part on the bike except the motor itself. I did have to rejet the carbs for the Harley exhaust and the intake I made. I also removed all the emissions crap. I can weld, fabricate etc. I just don't know Harleys off the top of my head and need a little help on the best direction to take on this bike. I'm really leaning towards replacing the back half of the frame. But a weld in hard tail is a few hundred more than repairing the original setup. I'd like some opinions and advice on my new-to-me bike since most of you have been-there-done-this-before.

[AusAndrew]

The motor mounts always seem to crack but it's a big job to change it. Don't know how successful re-welding it would be though. I would be hardtailing it personally but I guess it's all a preference thing. I think the 79-81 frame is the ugliest of the bunch in standard form. Mine is in getting a voodoo vintage hardtail installed at the moment, it was a nice looking piece of work, haven't seen it installed yet though. David Bird also does a hardtail for this model, he might chime in with his recommendations, I know his have been around for forever, I just preferred going single seat post with the voodoo hardtail.

Pictures suggest it is an S&S carb but my phone screen is too smashed to work out if that says E or B. I'm sure some of the guys on here that actually know a thing or two will verify the rest of it, I don't know shit.

[Noob2015]

The carb has the letter E on it not B. I think the rear swing arm the ugliest thing I've ever seen, its square stock and I don't think I can live with it. So I definitely think I'm going to do a hardtail on this. Besides it'll be more work to rebuild the original broken frame where the motor mounts than to just weld in the hard tail. The coil says Andrews on it. The generator says cycle electric. I still can't figure out if the previous owner actually bored out the cylinders by looking at the outside of the jugs. If anybody could give me some advice on how to find out if its been bored out without pulling the rockers off the top that would be helpful. I didn't have time to try and fire it up last night. I still have to drain the varnish out of the gas tank and clean out the carb before I try. I'd like to do a thick gauge steel rear fender with the hard tail setup so I can still have a passenger on the back when I want to. Will that cause me issues with it being a rigid or do you think I'll be okay? I'm single so I'd like to have the ability to take a girl for a ride on there. I can fab up pretty cool sissy bar on the back out of some round stock I already have in the garage. I also have 4.2 gallon fat Bob tanks that I'd like to use, a cylindrical oil tank and a used $200 springer front end. I'm not stoked about using the springer because it's only wide enough for a skinny front tire and no front brake calipers. I'm concerned about having only a rear brake. Should I use it? Or stick with hydraulic forks, or try to find a good deal on a wider springer on eBay or Craigslist? Everyone wants crazy money for them whenever I find one which is why I grabbed the one I have when I found it a couple years ago. I'd rather not go with a DNA springer, the last one I used didn't seem sturdy enough in the honda and I not sure I'd trust it on a rigid with a solid mounted motor and twice the power. Unless one of you think I'll be ok with using one? As I said, I'm new to the Harley, so any advice or input or info will definitely be appreciated. Thanks AusAndrew for your reply.

[Noob2015]

I looked at your voodoo vintage frame online. 219 for the builders kit is a great price. I think I'm gonna have to go with a pre fabbed one though. My frame is broken where the motor mounts and from what I've already read in the forums, that spot is critical to lining up the motor in the frame. Since mine is completely broken and the back swingarm is nearly disconnected from the bike, I don't think I'll ever be able to fab up the rear motor mount section exactly where it needs to be for proper alignment. Possibly if I go through re welding the frame together first, but then it seems I'm doing twice the work. I dunno

[Noob2015]

I checked out David birds hard tails and they look great too, but I looks like his expect me to use the stock portion where the rear motor mount attaches and that part of my frame is destroyed already.

[Noob2015]

I have another question. Like I haven't asked enough already. Lol. I'm settled on the hard tail conversion. I've seen several bikes with a drop where the hard tail welds on, like a funny angle. I'd like a straight line down the backbone and some stretch in the frame. First to make the ride a little better, the lines cleaner and to give me more room to mount the battery at the bottom and not have the rear fender right under my ass. Plus the stock frame geometry is really short and looks funny. Any ideas on the amount of stretch and drop if any I should be looking at? I can measure and get a better idea after I drop the motor. Just looking for someone whose done it already.

[AusAndrew]

You just have to get a solid picture in your head of how you want it to turn out, maybe find some pictures of other people's bikes for inspiration and work out if that includes a springer front end or not. People usually avoid dna springers because of their reputation for being shit quality. I think no front brake is a preference/confidence thing too, plenty of people do it and just as many say it's a bad idea. Once again, all down to the look you want. The dual disc is damn ugly but some people get away with it. I'm going drum front on mine I think.

Fender will be fine for passengers it it's mounted solidly enough. Just look how everyone mounts their king/queen set ups.

Not sure what drop and stretch is required to get a straight backbone. Might be worth you doing a rough mock up to get some measurements, see if it looks good or if it's too long. I have no idea about the geographics of America but people seem to use Haifley Bros, who also do a full kit with fender/oil tank/seat and stuff with their hardtail kits though I'm not sure if there's one for an 81, you could ask them if they have done the measurements already, then from what I gather Mike47 industries also does lots of custom hardtails, he might know too.

You really just need to get a clear image in your head of how you want it to look and just work towards that. Maybe post some pictures up and people can tell you what parts would be needed.

[Noob2015]

I appreciate the input. Right now I'm focused in seeing it fire up before I tear it down. So I know its OK. I drained the fuel tank and ckeaned the carb out and hooked up the battery. I get lights but no ignition. I look down at the generator and there's only one wire attached to the one of the two bolts on the generator. I looked at a basic wiring diagram I got off of the forum, but its not specific where the other line goes. So I've got a wiring issue ahead of me before I can hear it fire up. At least a get lights and I know the basic electronics for the most part okay. The previous owner started dismantling this to attempt to repair on his own, so I'm sure the issue is with that. I'm going to have to find a better wiring diagram or schematic to figure out what the other line that goes to my generator is. I assumed I could find the wire hiding somewhere close to the generator, but I did not. also my fuel line is bad going to the carb, so I need a replace that before I can even try.

[AusAndrew]

Get yourself a factory service manual and a factory parts manual. Seems to be rule number one of Harley's.

[Noob2015]

Working on it. Found a better wiring diagram, but its in electrical engineer language like a pile of spaghetti. Lol. It appears I'm missing a wire from the regulator to the generator. Before I fry a possibly good wiring system though, I'm gonna hit it when I'm sober and not drinking beers. I'm gonna have to also find the regulator before I can run a wire to the generator.