My first bike, the 1974 XL100

Thanks, I warmed up the engine but I wasn't sure about the throttle position for the compression check.

The coil is original. The next time the XL and CL are in the same place, I could try a swap. How would I go about testing it?
 
If it's the same as the coil on the 350 (6v single lead) set your voltmeter to lowest ohm setting and touch positive to the b/w wire coming out of the coil, then negative lead to the metal mounting bracket. Should read around 3-5 ohms. Switch to 20k ohms. Put positive on the plug wire lead, and keep negative on the mount, should be upwards of 10k, but check the manual for the actual values.

If you can't get a good reading at the plug wire try removing the plug cap, they often times get corroded and give a faulty reading.

Sent from my iPhone using DO THE TON
 
OK, great- I'll test the coil (with my good multimeter) and clean the connections the next time I work on the bike. Thanks for the tips!
 
Time for an update. I've been braaaapping all over the county on the XL and all's well. More on that, later. For now, feast your eyes on this fine piece of machinery I stole from my dad. We're pretty sure he used it for only one job, back in the '80s. Since then it sat dormant next to his Buffalo (unsurprisingly, he wouldn't let me steal that instead, though I tried). It'll be good to get some use out of it. Look how excited the oil can is!

sYzFNSv.jpg


The headroom above the existing workbench in the basement of our 100 year-old house was an inch shy of accommodating the drill press. Compared to the problems you come to expect with an old house, this is like being handed a glass of champagne that's gone just barely perceptibly flat; I happily built a new bench. The drill press is now squeezed between a massive beam and some cast-iron radiator plumbing, but with plenty of room to open the hood and adjust the belts.

VlQ3DkU.jpg


Show time! The first project will be panniers for the enduro. I decided to go with the same fat 50 cans I used on the scrambler, since they worked out great and anything bigger is probably overkill on a 200 lb machine. Boxes are pretty much ready for paint.

GgbeFUj.jpg


Mounting them might be a little trickier this time, but I think I have a plan.
 
Thanks for the tip, Limey. I use wire brushes in my RTX and drill motors all the time, but it may never have occurred to me to stick one in the drill press. Having two free hands sure makes manipulating fasteners easier.

Last weekend I had a chance to work on the panniers. I initially envisioned mounting them on a beer rack like I did with the CL, but those racks are kind of heavy and I don't like that they use the fender as a structural element, especially on the XL; the CL's fender has a nice curve to its cross-section, so it's fairly stiff, but the XL's fender is more broad and flat and mine's already dinged up enough from bouncing it into trees and stuff as a kid. I can imagine it folding easily under the weight of a rack and panniers. Probably just as bad, it's only held on by three dinky 6mm screws and two plastic sockets. I'm going to avoid placing a load on it.

Unfortunately, the upper shock mounts are the only two obvious tie-in points on the XL frame. I should probably just weld a couple tabs onto the back of the hoop, but since I'm a crap welder I chickened out and fabbed up a bracket that avoids modifying the frame.

qRYCwmx.jpg


The bracket slides over the back of the hoop, then the two bolts deform the flat bar up top, pinching it around the tube. It's solid, if a little funky.

Next I cut rails that run from the shock mount to the bracket out of the same 1/8" x 1" bar and fitted up the panniers. It may be a trick of the lens, but at least in photos they look surprisingly proportional on this bike, given their dimensions. I'm a bit shocked but I'm glad I stuck with the fat fifties.

GzuTHAr.jpg


Having the drill press makes this so much easier. I've been cruising CL for the past few weeks in search of a 14" vertical band saw and a belt sander to round out the basement workshop, but so far no deals have turned up. As it stands I'm cutting all the flat bar and channel with a hack saw. What a pain in the ass.

rpbI5K0.jpg


Now the plan is to add a stay from the bottom inside rear corner of each pannier to the bottom taillight-bracket mounting bolts on the fender. Hopefully this will be sufficient to stiffen the boxes up laterally. Vertically, the rails are good to go, but I could also weld a piece of bar flat along the top edge (so, like angle), which would help side-to-side rigidity. I'll try making the stays out of fender washers welded to 1/4" rod and see how it goes.

2rQxHCG.jpg


As you may notice in that last photo, spring has sprung around here and other projects are aggressively jockeying for my attention. Hopefully I can get back to the panniers soon.
 
Nice!

I finally got the ammo boxes mounted on the XL a few days ago. I am currently sorting out how to fab up a hinge so that the boxes only open from one side and I can shed some weight by cutting the original latch off.

Its been a giant pain in the arse getting them mounted, but looks like yours are going along smoothly.

Are the tie down hoops you have mounted to the cover there just aluminum drawer pulls? That's what I had in mind as well
 
advCo said:
Are the tie down hoops you have mounted to the cover there just aluminum drawer pulls? That's what I had in mind as well

Yep. Well, stainless, actually. I like the footman loops I used on the CL's panniers, but I wanted to do something different for the XL. I wish I had some extras I could send you- I used the rest as handles on some exterior storm transom windows we made for the house last fall. This is where I got them: https://www.amazon.com/gp/product/B00VMK8AHM

advCo said:
Its been a giant pain in the arse getting them mounted, but looks like yours are going along smoothly.

Ha! Time will tell- it wouldn't surprise me at all to run into an insurmountable problem and have to start over from scratch. Yesterday, though, I did ride the bike a few blocks back to my garage with the panniers attached like in the last photo, and nothing fell off, so hopefully my luck holds out.
 
This week I made the rear stays and finished mounting the panniers. I got lucky- everything fits and lines up surprisingly well. The stays attach to the fender and firm up the boxes a lot laterally. One minor issue is that the hoop bracket raises the seat about 1/8" in the rear. I gaffer-taped some big washers to the pan so it still sits on the frame tabs like it's supposed to. The bracket also makes reinstalling the fender tricky due to limited clearance, but I'm getting used to it.

I didn't snap any good pics, but I'll put up a few for the next round, which will be adding a platform between the panniers. Here's is a shot from this afternoon, in which I'm procrastinating from working on my taxes by experimenting with swapping out the original 49-tooth rear sprocket for the CL's old 43T:

SoBUFfI.jpg


I'll hang on to the big sprocket for when we cross the Darien Gap, of course, but for now gearing on the street is much improved!
 
My first bike, the 1974 XL100 - HELP, BURST PIPE!

So this happened at the end of my panniers shake-down ride last night. How?

bVLj2by.jpg


PfAKDQC.jpg


Before I left I adjusted the valves, timing, and points. I was out for a few hours and all was mellow until the very end- the pipe exploded coming up a hill about 2 miles from home. At the time, I thought the bike backfired, but maybe it was the sound of the weld ripping open? I did have the motor wound up a bit when it gave.

Over the weekend I cleaned the slinger. Think I torqued the pipe when I reinstalled it? It went on easily enough, and the rip is behind the rear mounting point, so I kind of doubt it. My ride included about 10 miles of deep gravel but that was early on and there aren't any scratches anywhere. The bike still runs fine, albeit louder and now the idle hangs. Any ideas?
 
Thanks, firebane. I pulled the carb and don't see any cracks in the manifold or insulator. The carb, airbox, and tube look normal, too.

WTF did I do? I have about 600 miles on this bike since bringing it out of the shed.
 
That's strange. The first thing that comes to my mind is that the seam there had been weakened due to rust on the inside from years of sitting. Then the back pressure from recent riding further weakened the seam and it blew. The entire bottom half of the muffler on my XL was rotted away when I got it, so even years of condensation building up and water standing in the seam could've weakened it significantly.


Sent from my iPhone using DO THE TON
 
Good call- I bet you're right. Well, it's at the welder's now. Nothing was rattling inside, but before I dropped it off I couldn't resist shoving the endoscope in to have a peek. Looks pretty exciting in there.

https://youtu.be/8MvEUwjug-Y

https://youtu.be/Av3DYZzsUbA
 
voqzMgr.jpg


Here's the source of that persistent oil leak. A pin hole had opened between the cooling cavity and cam chain galley due to 12 year-old me never adjusting the chain.
 
I found a new (used) cylinder on eBay for $20 that was in great shape. There's a guy with a small machine shop down the street from my house that specializes in engine work so I took it to him for a hone. He doesn't normally do small engine work (when I went in he had a truck crankshaft sitting on a bench that looked like it weighed more than my entire bike), but he was also happy to clean up the dome of the combustion chamber, which had a bit of a nick in it from who-knows-what, and lap the valves.

GBiplQ1.jpg


5QZuCrt.jpg


I7a9eXv.jpg


kYJlJxd.jpg


5xykHpA.jpg


stLcMX9.jpg
 
That all happened back in March of last year, so I had the whole season to enjoy the bike.

Ad4NEEI.jpg


Zff1bD7.jpg


Ek89eiX.jpg


zCkdopQ.jpg


The last shot was on the way to the White Rose swap meet in June. It looks like some farmer's driveway but it's actually a very cool county road. I hope.
 
Back
Top Bottom