18/30 now how do I retard the timing on a points bike

miller0613 · Full Member Joined: Jun 27, 2007 Posts: 111

I know this is the drive section but I switched the chain and sprockets and now need to retard the timing and don't know how. XS John outlines very well how to do it on a EI bike and I have read somewhat how to do it with a light but is there a way to do it simply without a light. If so could someone walk me through it? thanks

jayel

you would want the points to break earlier, before the F mark and not go to the full advance line, you can set the points with a static timing light or Ohm meter but there is no subsitute for the final check with a strobe light in my opinion

miller0613 · Full Member Joined: Jun 27, 2007 Posts: 111

I think that I understand this but how do I adjust the timing I know ( ish ) where it should be set but how do I adjust it?

weekendrider

Like jayel said you have to set each set of points so you may want to scribe a line instead of just eyeballin it.

jayel

if both sets of points were set correctly and opening at the normal setting, rotating the back plate would retard both sets of points

miller0613 · Full Member Joined: Jun 27, 2007 Posts: 111

rotating the back plate which way will retard the timing?

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

deleted

miller0613 · Full Member Joined: Jun 27, 2007 Posts: 111

so loosening the larger (A) screws in the diagram will loosen the back plate correct?

jayel

miller0613 · Full Member Joined: Jun 27, 2007 Posts: 111

So today I decided to go after the timing without a light and just do it by feel. A process that provided mixed results. I scribed a mark on the backing plate loosened the screws that secure the backing plate and attempted to move the plate counter clockwise. ( One note, my bike was running well but missing and sputtering around 2100-2500 after the new chain and sprockets) There was no room to move the plate counter clockwise so I took the plate off and filed it down so that it would allow me to move it approximately 1/4" from my mark. Tighten everything down and it wont run. Start idle die. Start idle give gas die. Adjust the mixture and idle screws runs idles give it gas dies. After an hour or so of this I decied to set the idle screws to 2 and 1/4 turns and move the backing plate 1/4" past my mark clockwise. Starts runs drives. Kinda doggy but runs and is smooth, doogy ,but smooth, at 2000 or so rpm. Move the plate a touch counterclockwise runs drives a little peppier until I run out of gas a mile down the road push it home its dark and starting to rain will try again tomorrow may ust have it

jayel

1/4" is a long ways on moving a timing plate beg, or borrrow but don't steal a timing light before you screw something up totally

miller0613 · Full Member Joined: Jun 27, 2007 Posts: 111

I would say it was more like 1/8th of an inch or so I was just venting my electric start turns over now but rarely starts the bike so a couple hours of kicking had me to the breaking point

acbanks

You can check your timing with a multimeter to see exactly when the points open. (You'll have to disconnect the points wiring or it'll find a ground through the condenser) A light really is helpful to double check, and I won't kick mine until I double check timing.

So what's the benefit of this retarded timing? I'm guessing that because it fires late there's a longer push of expanding gases in the compression stroke and slightly more torque? Doesn't that also mean the mixture is still burning in the exhaust pipes?

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