{"id":20503,"date":"2023-01-01T00:01:21","date_gmt":"2023-01-01T08:01:21","guid":{"rendered":"https:\/\/exhaustnotes.us\/blog\/?p=20503"},"modified":"2022-12-31T22:03:12","modified_gmt":"2023-01-01T06:03:12","slug":"weve-come-a-long-way-baby","status":"publish","type":"post","link":"https:\/\/exhaustnotes.us\/blog\/index.php\/2023\/01\/01\/weve-come-a-long-way-baby\/","title":{"rendered":"We’ve come a long way, baby…"},"content":{"rendered":"
By Joe Berk<\/h6>\n

Susie and I recently visited the Franklin Automobile Museum in Tucson, Arizona, and while we were there I photographed their 1913 Thor Model U motorcycle.\u00a0 It’s a fascinating machine from many perspectives, one of which is what those guys had to do back in the day to start their motorcycles.\u00a0 Today, we have electric starters and fuel injection…hit the ignition, touch the starter button, and go.\u00a0 Turn back the clock 15 years or so and it was open the fuel petcock, close the choke, turn on the ignition, and hit the starter button.\u00a0 Turn back the clock 50 or 70 years and you have to add kickstarting to the mix.\u00a0 Go back a century or more (for this 1913 Thor, it would be a cool 110 years), and wow, you practically had to go to Thor University to learn the drill.<\/p>\n

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The 1913 Thor as viewed from the left side. The large lever extending up from the crank is the clutch. The drive chain on the left is one of two chains on this motorcycle. The left handgrip operates the throttle and the clutch. Think about that:\u00a0 Your left hand operated the throttle and the clutch.<\/figcaption><\/figure>\n
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The 1913 Thor Model U on its centerstand. Note the rear wheel ground clearance, the bicycle pedals, and the chain on the right side. There’s no front brake; the bicycle pedals operate a rear wheel coaster brake, like you might have had on your Schwinn in the ’50s or ’60s.<\/figcaption><\/figure>\n

Starting a Thor would keep a rider busy.\u00a0 The bike had to be on its rear wheel centerstand to get the rear wheel off the ground (why will become clear in a bit).\u00a0 Then you had to put the engine in gear by pushing the clutch lever forward.\u00a0 You might think that’s counter-intuitive.\u00a0 Read on, blog acficionados.<\/p>\n

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The clutch lever is on the left side of the motorcycle, and the “T” at the top operated the optional two speed transmission (as shown, the transmission is in first; turn the lever 90 degrees and it’s in second).<\/figcaption><\/figure>\n

If your Thor had the the optional two speed rear hub transmission (a $40 option on top of the motorcycle’s $290 price in 1913), you would want to make sure it was in the high gear position.\u00a0 You do that by turning the T-handle on top of the clutch lever parallel to the motorcycle.\u00a0 Having the bike in second gear would make the engine easier to turn over; it would be like putting your bike in second for a run-and-bump start\u00a0 (and I realize as I type this how few readers will know what a run-and-bump start is).\u00a0 \u00a0But we’re not going to run-and-bump this priceless 1913 Thor.\u00a0 Stay with me; this is going to get interesting.<\/p>\n

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Fuel petcocks under the left forward side of the fuel tank. The rear petcock allows fuel to flow to the carburetor. The forward petcock allows fuel to be removed for priming the cylinders or, as the owner’s manual states, “for any purpose.” It included a small cup for this purpose.<\/figcaption><\/figure>\n
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The right side of the mighty Thor 1000cc twin. Those little protuberances on the outboard side of the valve covers (bear with me; I’ve been looking for an excuse to use the word “protuberance” all day) are where you dump raw fuel to prime the engine. No kidding.<\/figcaption><\/figure>\n
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Another view of the priming port.\u00a0 The spring you see in this photo is the intake rocker return spring.<\/figcaption><\/figure>\n

Next up:\u00a0 Prime the engine by taking a bit of fuel from the Thor’s fuel tank priming petcock and manually inject gasolina<\/em> into the intake cups (the Thor has openings in its intake domes for this purpose…those Thor engineers thought of everything).\u00a0 Or, you could use the optional device on top of the fuel filler cap to extract a bit of fuel.\u00a0 Like I said, they thought of everything.<\/p>\n

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The right twist grip operates the ignition advance; the left twistgrip operates the throttle. The lever on the right handlebar is a compression release.\u00a0 It could be locked in the compression released position to hold the exhaust valves open.<\/figcaption><\/figure>\n

You then retard the ignition timing via the right twistgrip (you read that right; the left twistgrip works the throttle) by twisting it clockwise.\u00a0 Having the ignition fire after top dead center, you see, makes it easier for the engine to catch a spark and continue running.\u00a0 \u00a0So where’s the throttle?\u00a0 That’s on left handlebar.\u00a0 Open the left twistgrip a bit by turning it clockwise.\u00a0 It will stay where you leave it; there’s no return spring.<\/p>\n

That funny little chrome lever on the right handlebar?\u00a0 It’s not a clutch (remember, that was ginormous lever to the left of the fuel tank).\u00a0 The little right-handlebar-mounted lever is a compression release.\u00a0 Pull it in, and it opens the exhaust valves to, well, release the compression.\u00a0 It makes it easier to pedal, and we’ll get to that momentarily.\u00a0 Maybe you didn’t believe me when I told you this was a complicated undertaking.\u00a0 \u00a0Read on.\u00a0 It gets even more interesting.<\/p>\n

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Thor Plumbing 101: The “forward filling nipple” (Thor’s terminology; we’d call it a fuel filler cap) is where the gas goes.\u00a0 Thor recommended any “standard grade gasoline,” but advised straining it through a chamois first (things were different in 1913).\u00a0 The gizmo on top of the fuel filler cap extracts a bit of gas that can be transferred to the priming ports.\u00a0 The center cap is for oil; Thor also recommended straining the oil before pouring it into the oil tank.\u00a0 The third (and rearmost) device is a needle valve that should be left open to allow oil to flow into the reservoir immediately below the tank (and from there, to the engine).<\/figcaption><\/figure>\n
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The Thor oil reservoir, complete with sight glass.\u00a0 That little petcock halfway down the oil line?\u00a0 Make sure it’s open before you start the motorcycle!<\/figcaption><\/figure>\n

The Thor has a total loss lubrication system.\u00a0 That term, total loss, doesn’t describe how your 401K account is doing these days; it refers to how the engine uses oil.\u00a0 It uses and consumes it (it’s not returned or recirculated).\u00a0 Think of it as Autolube for four strokes.\u00a0 Ah, shoot, I’ll bet a lot of you are too young to know what Autolube is, too. Gresh can explain it later.\u00a0 Back to the main attraction, that total loss lubrication system…there’s an oil petcock halfway down the oil line on the left side of the motorcycle, between the sight glass and the crankcase.\u00a0 It needs to be open (you may void your warranty if operate the motorcycle with it closed).\u00a0 The Thor would consume a quart of oil every 50 to 300 miles depending on conditions and your riding style, but the tank carried a gallon, and with a top speed somewhere between 50 and 65 mph (again, depending on conditions, the rider, and whether or not you had the optional two speed transmission), it’s not likely you would run out of oil.\u00a0 “They smoke a lot,” one Thor expert told me, “so as long as you see blue smoke behind you, you’re good.”<\/p>\n

The last bit of preparation involved closing the choke on that big tomato can Thor carb nestled in the V between the cylinders, and that involved two actions:\u00a0 Closing a thumbscew on the carb’s rear and screwing down a tapered knob on top.<\/p>\n

All right…now we’re ready to get to the good part.\u00a0 You may have noticed that the Thor has two chains (one on each side of the motorcycle) and a set of pedals (like a bicycle).\u00a0 Once you have completed all the actions described above, you can get on the Thor and start pedaling like Lance Armstrong charging up the Col du Tourmalet<\/em> (I say that figuratively; the good guys at the Franklin Automobile Museum are not going to let you climb onto their 1913 Thor).\u00a0 \u00a0Your pedaling is going to drive the rear wheel via the chain on the right side of the motorcycle from the pedals’ chainring to the rear wheel sprocket.\u00a0 That’s going to spin the rear wheel and tire (which is why we wanted the bike on its centerstand), transmit the rotational inertia you generated through the rear-hub-mounted transmission, turn the drive chain on the left side of motorcycle, transmit your torque through the clutch (which we engaged earlier) and spin the Thor’s 61-cubic-inch V-twin.\u00a0 As you ponder all of that, be thankful that you’re not trying to crank the 1914 Thor’s larger 74-cubic-inch engine, and be thankful that I clued you into actuating the compression release.\u00a0 And finally, be thankful that you’re adding the rear wheel and tire’s flywheel effect to what you (the motive force in this cacaphony of early American motorcycle starting activities) have set in motion.<\/p>\n

Once you’ve attained sufficient rotational inertia, release the right handlebar compression release.\u00a0 \u00a0If Thor and the other ancient Norse gods are smiling, the engine will catch, and you’ll hear the opening chords of that delightful “potato-potato-potato” V-twin symphony we Americans love.\u00a0 As soon as you are sure the music will continue, pull that large left clutch lever rearward to disengage the clutch and reverse direction on the pedals (like you would have on the Schwinn you rode as a kid).\u00a0 As mentioned earlier, there’s a coaster brake back there; in fact, it’s the only brake on this motorcycle.\u00a0 While the engine is warming up, advance the ignition (with the right twistgrip), open the carb choke (it involves two actions, as mentioned above), and then, as the owner\u2019s manual explains with early American Aurora\u00a0 engineering precision, apply \u201ca trifle\u201d of throttle (with the left twistgrip).\u00a0 \u00a0The owner’s manual authors’ descendants, I’m sure, went on to become writers for Saturday Night Live<\/em> in the early days when that show was still funny.\u00a0 One more thing…if it’s a cold day, Thor recommended placing a rag soaked in warm water around the carburetor\u2019s float chamber.<\/p>\n

Once everything is percolating to your satisfaction, roll the motorcycle forward off the stand (Pro Tip:\u00a0 Remember to disengage the clutch first), and while adjusting the throttle, feather the clutch lever forward to start moving.\u00a0 As you read this, think about simultaneously feathering that clutch lever and<\/span> working the throttle with both of your left hands.\u00a0 Whew!<\/p>\n

After writing and then reading the above, I think I’m going to step out into my garage and start my Enfield 650.\u00a0 By pressing a button.\u00a0 Just because.<\/p>\n

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Never miss an ExNotes blog:<\/p>\n\n","protected":false},"excerpt":{"rendered":"

By Joe Berk Susie and I recently visited the Franklin Automobile Museum in Tucson, Arizona, and while we were there I photographed their 1913 Thor Model U motorcycle.\u00a0 It’s a fascinating machine from many perspectives, one of which is what those guys had to do back in the day to start their motorcycles.\u00a0 Today, we … Continue reading “We’ve come a long way, baby…”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":20505,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":true,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[392,140],"tags":[3281,3053,3277,3278,3282,3279,3280,1197],"class_list":["post-20503","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-back-in-the-day","category-vintage-motorcycle","tag-1913-thor","tag-franklin-automobile-museum","tag-thor","tag-thor-model-u","tag-thor-motorcycle-operation","tag-thor-starting","tag-total-loss-oil-system","tag-vintage-motorcycle"],"jetpack_featured_media_url":"https:\/\/exhaustnotes.us\/blog\/wp-content\/uploads\/2022\/12\/20221209_0266-900.jpg","jetpack_sharing_enabled":true,"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/posts\/20503","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=20503"}],"version-history":[{"count":23,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/posts\/20503\/revisions"}],"predecessor-version":[{"id":20634,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/posts\/20503\/revisions\/20634"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/media\/20505"}],"wp:attachment":[{"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=20503"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=20503"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exhaustnotes.us\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=20503"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}