Author Topic: Ignition help needed (Read 3284 times)

Steph_GSF400VV · « **on:** March 21, 2006, 03:44:23 PM »

My bandit is suffering from a weak spark when starting when shes cold. Once its warm its fine and runs like a dream (thanks to the new race tuned engine).

Ive been told its not the Digital Igniter because if that was blown it wouldnt run at all.

The signal generator is working fine so its not that either.

Ive changed the plugs too so its not them. Does anyone know what else it could be or is it worth putting new coils and plug leads on it? and if so wheres best to get them in the uk?

Cheers, Steph.

Krautwagen · « **Reply #1 on:** March 22, 2006, 12:52:33 AM »

Most of the ignition system isn't that temperature sensitive.

Are you sure it's spark and not the choke circuit?

bonobandit4 · « **Reply #2 on:** March 22, 2006, 10:37:45 AM »

Quote from: "Krautwagen"

Most of the ignition system isn't that temperature sensitive.

Are you sure it's spark and not the choke circuit?

What exactly do you mean? Stickey choke? Not closing fully?

I'm having a similar problem. I know I'm getting some spark, but 1 and 4 aren't as consistent as 2 and 3 as far as heating up the header pipes. I can get it to turn over with starter fluid, but it won't keep running. Of course, with the tank off, the only fuel going in is in the ~18" of tubling I have setup, and I'm thinking I need to pinch the vacuum tube with no petcock in place while I'm working on it. Maybe it's just lack of vacuum, but I'm worried because my choke is not cooperating at all. It is impossible to close with the lever. I have to reach down and pry it closed with a screw driver now. Suggestions?

Also, is it supposed to feed fuel direct when it's choked. I can see the fuel level fall after I pry the choke closed.

Thanks,
B

Red01 · « **Reply #3 on:** March 22, 2006, 10:45:21 AM »

It's supposed to flow fuel when vacuum is applied to the petcock. Choke position has nothing to do with the petcock.

Try moving your coils to see if the problem follows the coil. If it moves, the coil or their leads are bad, if it doesn't, your plugs or the black box is the problem.

bonobandit4 · « **Reply #4 on:** March 22, 2006, 10:49:36 AM »

Moving 2/3 to 1/4, and vice versa won't cause any timing problems? Or, are you saying to just swap coils, and leave everything else in place? Duh. My bad.

Question tho... If I'm working on it with the tank and petcock off, do I have to pinch the vacuum tube when running it? Otherwise it won't get vacuum to the carb....

PitterB4 · « **Reply #5 on:** March 22, 2006, 11:13:55 AM »

Quote from: "bonobandit4"

I'm having a similar problem. I know I'm getting some spark, but 1 and 4 aren't as consistent as 2 and 3 as far as heating up the header pipes. ...with the tank off....I'm thinking I need to pinch the vacuum tube with no petcock in place while I'm working on it. Maybe it's just lack of vacuum...

Ding, ding, ding. #1 won't run right with the tank off unless you pinch the vac hose. I use a small vice grip. That doesn't explain # 4, tho.

1 & 4 both run off the left coil, right (bike & manual at home, pitter at work)? Check the connections to that coil.

PitterB4 · « **Reply #6 on:** March 22, 2006, 11:16:34 AM »

Damn - you guys were typing while I was responding....

No - swapping the coils is a good troubleshooting technique. Just double check the connection to that left coil b/f going to that trouble.

BTW - you do need to address that sticky choke. You're gonna foul plugs quickly if it won't close completely.

bonobandit4 · « **Reply #7 on:** March 22, 2006, 11:18:13 AM »

Thanks Pitter! Good news! I was thinking about that, but haven't had time to get back into the garage since Sunday... I think #4 wire was a little loose, but it may have been warmer than 1 also. I'll check the spark on 4, more after the weekend...

bonobandit4 · « **Reply #8 on:** March 22, 2006, 11:22:03 AM »

Quote from: "PitterB4"

Damn - you guys were typing while I was responding....

No - swapping the coils is a good troubleshooting technique. Just double check the connection to that left coil b/f going to that trouble.

BTW - you do need to address that sticky choke. You're gonna foul plugs quickly if it won't close completely.

okay, I just want to make sure I'm clear. When you "choke" the carbs, you're closing the choke, correct? That's what I meant. I always make sure that I open it back up after I choke it...

Suggestions on stickey choke? Lots of carb cleaner I suppose...

Red01 · « **Reply #9 on:** March 22, 2006, 12:05:04 PM »

Is it sticky on the carbs, or sticky thru the choke cable?
(The B4 does use a cable, right?)
In any event, clean the offending moving parts and lubricate.

Steph_GSF400VV · « **Reply #10 on:** March 22, 2006, 04:55:26 PM »

Hey guys success with my bandit.

We started it on sunday using 'easy start' fluid. Then took it out for a 4 hour blast into wales. Used the rev range and varied the speeds to clear her out and now *fingers crossed* for the passed 3 days shes starting on the button.

It hasnt been ran since the engine change so my theory is just that the bike needed a good run out to settle things in.

I went out on it tonight and its running perfect.

So problem solved. I might order some new plug leads and coils just to change when i have the tank off so i dont have to worry about them in the future tho.

Thanks guys, Steph

PitterB4 · « **Reply #11 on:** March 22, 2006, 05:14:20 PM »

Quote from: "Steph_GSF400VV"

Hey guys success with my bandit.

I'm glad cuz your thread sure got hijacked!!!!!

Glad you got her runnin' well!

bonobandit4 · « **Reply #12 on:** March 22, 2006, 06:36:02 PM »

Quote from: "PitterB4"

Quote from: "Steph_GSF400VV"
Hey guys success with my bandit.

I'm glad cuz your thread sure got hijacked!!!!!

Glad you got her runnin' well!

I resemble that remark! Sorry bout that.

Congrats!

Krautwagen · « **Reply #13 on:** March 23, 2006, 12:21:03 AM »

Quote from: "Steph_GSF400VV"

It hasnt been ran since the engine change

Engine change? That may have been helpful to know.

Brian, it sound like you've got some carb work to sort out. A thorough cleaning and reset to base settings would be a good start. While doing that, free up that choke.