spark issues on 79 bobber

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

So i have been building a bobber over the last month and it's coming along great thanks to alot of the posts on this website. I've recently built a custom harness for the bike (which ran before i took it apart) and now i'm trying to get it to spark. I'm using all stock equipment because i'm a broke college student, so that means i'm running the stock points, stock coils and stock seperated regulator and rectifier. i did recently buy a new battery for it and i believe i have it all wired up right. does anyone have any specs i could compare to as i do have a dvom on hand. or maybe someone could post a known good schematic for this set up. i have included a schematic that shows how i currently have the bike wired.

highspeedhamish · Full Member Joined: Jun 25, 2009 Posts: 62

www.cyclepsycho.com/ya...wires.html

1ironhead · Posted: July 14, 2009, 9:02 am Post subject: Re: spark issues on 79 bobber

Here's another w/o turm signals.

1ironhead · Posted: July 14, 2009, 1:43 pm Post subject: Re: spark issues on 79 bobber

Here.This is a little easier to follow....still learning the computer.

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

thanks i'll reference that tonight and see if i can work things out

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

is there any way to test my coils or condensers? also how do i know which wire from the points goes to each side. i'm guessing it's gonna backfire real bad if i get it wrong.

pumps · Posted: August 5, 2009, 12:31 pm Post subject: Re: spark issues on 79 bobber

R is for left. L is for right.
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Testing coils & condensers pages 54 and 55 I think.
www.knucklebusterinc.c.../XS650.pdf

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

wow thanks for that link to the repair guide. i'll have to do some reading in that bad boy. and by chance do you know the colors of those wires and what cylinder they go to?

baclay9 · Full Member Joined: Jul 30, 2009 Posts: 88

On my 79 as your sitting on the bike the white goes to the right coil and the orange to the left.

cpt137 · Full Member Joined: Jan 10, 2009 Posts: 97

Make sure your plug wires are screwed all the way in the coil and caps. Don't ask why.

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

i know this is an old post but i got the bike running, but it's really rough. by rough i mean an incredibly high idle. and when i rev the throttle it will raise rpm way up then stay there until i kill it. the carbs were just rebuilt with mike's xs kit. i'm running air pods and straight pipes. do i need to rejet or am i missing something? also what are those two openings that had air hose going to the oem airbox? some kind of pcv?

pumps · Posted: September 4, 2009, 3:06 pm Post subject: Re: spark issues on 79 bobber

When you have put freer flowing pod filters on it you have increased the airflow and caused it to run leaner. I believe the two openings you refer to is something like a pcv set up.The stock airboxes create a vacuum to draw gases out of the crankcase. Some guys will put a one way valve on there. I think mike sells one. Read this.
www.650rider.com/index...pic&t=7175
As far as the jetting, I don't know but I will say to be sure you don't have a vacuum leak where your carbs connect. Also check your throttle cable(s) to be sure they are returning fully to the idle position and not binding.

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

ok i'm pretty sure i don't have any air leaks... and i'm currently tuning it without an air pod. Even with the extra air, the plugs are black which tells me its running rich. when i adjust the air fuel mixture it doesn't change much. and when i rev it up, it will stay at the higher rpm until i kill it. also the throttle cable is not sticking and alows the carbs to snap back.

yamaman · Posted: September 16, 2009, 12:58 pm Post subject: Re: spark issues on 79 bobber

Make sure your advance mech is snapping back as clean as your carbs are!

minkistinkis · New Member Joined: Jul 13, 2009 Posts: 7

how do i check that?

pamcopete · Posted: September 17, 2009, 5:47 am Post subject: Re: spark issues on 79 bobber

Video works better the second time.

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