View Single Post
Old 03-16-2008, 01:38 AM   #68
Gnarly Adventurer
Joined: Feb 2008
Oddometer: 315
Originally Posted by tcs
I'm no expert, but let's see...

Standardized controls are a fairly new thing in motorcycling, having come about really only in the last 40 years or so and still not totally universal worldwide.

These very old bikes will typically have a clutch, which could be as simple as a belt tensioning roller, usually worked by a hand lever. It's not spring loaded like modern clutches; push the clutch lever in and it will stay when you take your hand off. The throttle is probably a twist grip even from the earliest days, but you might not notice it in pictures because the cables were often run inside the handlebar tube. Some very old bikes will have an amazing system of external linkages instead of hidden cables! That throttle was probably on the right grip (most folks have right master hands) but not always. Then you'll need a spark advance lever, a compression release lever, a shift lever (well, if your bike has a multi-gear transmission, which came around 1910-1912 for most makes), and of course a lever on the oil pump for the rider to lubricate the top end. Then there'll be a kill switch, perhaps a muffler cut out lever, and, so the rider's feet didn't feel completely left out of the riding experience, a foot lever for the rear (only!) brake.

All these bikes will have unique features, but in general to get underway: put the bike up on the (center) stand, open the kill switch and petcock, tickle the carb, give the oil pump a few strokes, set the spark advance, open the compression release, disengage the clutch, select the best gear for starting, engage the clutch, put your hand on the throttle and then begin to pedal. As the engine begins to spin, close the compression release, carefully give it some gas and - voila - the engine began to fire. Quit pedaling, engage the clutch, tap the brake to stop the rear wheel from spinning, get the bike down off the stand, select first gear, tweak the spark advance, give the oil pump another stroke, disengage the clutch as you give it some gas and ride away.

Perfection! What could be simpler?
Thanks; that's exactly the sort of explanation I was looking for. Fascinating. I'd like to see a video of that start-up sequence. :) I don't even know what spark advancing or compression releasing is.
CGameProgrammer is offline   Reply With Quote