Author Topic: Starting problem  (Read 6758 times)

Offline t6nis

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Starting problem
« on: August 31, 2013, 06:31:32 AM »
Hey guy's, it been a long time since i've been here. I was in the army. But anyhow, i have two problems with my bandit.

The first one is that when i rebuild it, had new crankshaft and new crankshaft bearings installed, i don't know what they are called in english, but i think u know what i mean. I rebuild the bottom end.
And when i put the bike together i could not make it to run. The spark plugs are wet and there is a spark, but it will not run, it kinda fired once for like 2 seconds or so but it did not ideled. And after that it just like kinda wanted to go to work, but it did not start. I changed the caps in the CDI for like 2 year's ago or so. But it did not have any starting problems like a year ago, after i went to the army it stay'd at my friends house and he did the bottom end rebuild. I have to say that the timingi is perfect, that could not be the problem.

The second problem is that even if i want to buy the new CDI, i dont have the numbers on the CDI. Is there a possibility of somehow finding out what CDI is suitable for my bike? I know I once had a cdi from a friend and that one worked for me, but i have lost the paper where i wrote the number.

Offline Mechannibalism

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Re: Starting problem
« Reply #1 on: September 01, 2013, 04:00:36 PM »
Are you SURE it's the CDI ?  and not cam timing or valves too tight or carb flooding or coil/spark plug wires mixed up?  I take it that you never have got  it running after the rebuild.

Offline interfuse

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Re: Starting problem
« Reply #2 on: September 03, 2013, 05:17:07 PM »
Are you using fresh gas?

My bike sat for a year with stabil in the tank and when I went to fire it up it wouldn't go. So I checked spark and it was good. So I figured it was time to clean the carbs. When i drained the gas out of the carbs it was orangey in colour. I opened up the carbs and everything was clean. I tried again to refire with old gas and it wouldn't go.

So I drained the tank, the float bowls and put in fresh gas and it fired right up. Needless to say I wont let gas sit for that long again.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline t6nis

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Re: Starting problem
« Reply #3 on: September 03, 2013, 05:53:36 PM »
yea, i did rebuild the carbs also, and used fresh fuel

Offline B4ndit

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Re: Starting problem
« Reply #4 on: September 03, 2013, 06:12:22 PM »
If the plugs were wet then you have a fueling problem. Have you replaced the plugs and tried to start? If it wont idle you still have a carb problem.

Offline t6nis

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Re: Starting problem
« Reply #5 on: December 06, 2013, 08:31:08 AM »
It must be the spark plugs, cuz i measured the resistance of the primary and secondary coils. The primary was ok, but the secondary only gave me 16 kohms, but it should be at least 30

Offline ventYl

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Re: Starting problem
« Reply #6 on: December 07, 2013, 03:16:09 PM »
Don't rely on secondary wiring resistance. Resistances on mine coils have difference of less than 1 kiloOhm but one coil works fine and second does not. But even with one coil non-functional I am still able to start it running rough just on two inner cylinders. By swapping coils I can get it running on two outer cylinders.
Bandit 400 1991 - stock except of swap from GK75B to GK75A

Offline t6nis

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Re: Starting problem
« Reply #7 on: January 11, 2014, 07:52:18 AM »
So, i bought myself a set of brand new coils, fresh of ebay. Everything is neat and tighty as it should be, but i still have a problem with my ignition. I wire everything up and when i push the starter button, the spark is kinda random, 2 out of three times it gives me a spark but at the third time there is nothing, no spark whatsoever. What could be the problem? CDI? If so, how can i identify the cdi without having the sticker on it.

Offline interfuse

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Re: Starting problem
« Reply #8 on: January 11, 2014, 08:14:55 AM »
Have you tried cleaning the safety switches? If the clutch switch is grimey it can make an intermittent connection problem and you won't get a spark some times.
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline t6nis

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Re: Starting problem
« Reply #9 on: January 11, 2014, 08:23:35 AM »
but there is no cluch switch, it's only connected by a cable. Im running out of ideas here. i changed the coils cuz the resistance of the secondary coil was way to low. But now i have a weak spark or no spark at all

Offline ventYl

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Re: Starting problem
« Reply #10 on: January 11, 2014, 11:54:27 AM »
first make sure that all input of CDI are correct and wiring from CDI to ignition coils is in good condition. inputs for CDI are 12V switched and crankshaft sensor. you can check wiring with V-meter. exact condition of crankshaft sensor cannot be checked without scope but you can check resistance of sensor. if all wirings are OK and sensor resistance too, maybe you'll need to do CDI repair.
Bandit 400 1991 - stock except of swap from GK75B to GK75A

Offline SoEazy

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Re: Starting problem
« Reply #11 on: January 13, 2014, 09:47:59 PM »
but there is no cluch switch, it's only connected by a cable. Im running out of ideas here. i changed the coils cuz the resistance of the secondary coil was way to low. But now i have a weak spark or no spark at all

The clutch switch is between the lever and perch. It's really easy to bypass and tuck the wires in the headlight bucket, I know it came on U.S. models.  At least that's what I did with mine. I doubt it's your problem though. I think it only prevents the engine from turning over not from making spark.

Have you checked the signal generator? This part goes bad often from sitting in hot oil and vibration from the engine. Also, you will not get spark if this part doesn't work properly. Good luck.
There's no such thing as a free bike.

Offline interfuse

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Re: Starting problem
« Reply #12 on: January 14, 2014, 11:32:48 AM »

The clutch switch is between the lever and perch. It's really easy to bypass and tuck the wires in the headlight bucket, I know it came on U.S. models.  At least that's what I did with mine. I doubt it's your problem though. I think it only prevents the engine from turning over not from making spark.

You sir are correct. The safety switches result in no crank... I'm getting forgetful in my old age...
Mike

'91 GSF400
It's more fun to ride a slow bike fast than a fast bike slow.

Offline t6nis

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Re: Starting problem
« Reply #13 on: January 15, 2014, 11:03:29 AM »
I just checked the signal generator. It showed me resistance of 2.5 ohm, but the manual gives me an resistance of 80-120 ohm. Soooo, this might mean that i have found the problem, buut, this raises another problem, where do i get a new signal generator?

Offline SoEazy

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Re: Starting problem
« Reply #14 on: January 15, 2014, 11:35:30 AM »
I bought mine from Bike Bandit. Here's the link to the page:

http://www.bikebandit.com/1992-suzuki-bandit-400-gsf400/o/m147864#sch248461
There's no such thing as a free bike.