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General Category => Maintenance => Topic started by: twangin4u on March 28, 2016, 07:22:51 PM

Title: No spark
Post by: twangin4u on March 28, 2016, 07:22:51 PM
Are those digital igniter boxes dependable? I have power to my coils and they ohm out good, but I'm not getting the signal ones the orange and grey wires to spark. The side stand safety switch has been removed and there's a wire dangling down underneath that I'm assuming goes to the oil level sensor. The bike is at a buddies house until I can get it running so it's hard to get a lot done on it like that. The bike sat for six years and I was told it sparked then but you never know. Anyway, does the side stand switch have a lot to do with the bike sparking if it's in neutral?
Title: Re: No spark
Post by: FJmonkey on March 28, 2016, 07:30:49 PM
I just checked, my '89 will start with the side stand down and in neutral.... My '86 was the same.
Title: Re: No spark
Post by: twangin4u on March 28, 2016, 07:51:31 PM
Ya my'84 is the same. Only time it kills motor or prevents starter from turning is when it's in gear. There's been nice living in the bike too I've noticed.
Title: Re: No spark
Post by: Pat Conlon on March 28, 2016, 08:15:51 PM
I suspect the critters have chewed your wiring.

1) check the ohm reading your ignition pick up coils (from the plug at the igniter box) if ok, then...
2) run power and ground directly to the igniter box from the battery. This will bypass all other sidestand/neutral switch/ignition key circuits.

If it does not run, it's the box....if it does run, it's the outside circuits causing power interruption to the box.

Your sidestand switch is a normally closed circuit. Without a functioning switch, you need to tie the 2 wires together to get power to the igniter box.
Title: Re: No spark
Post by: twangin4u on March 28, 2016, 10:36:39 PM
Thanks Pat. I did ground the orange wire yesterday and it did give a spark, but I haven't ohmed the igniter box yet. The weird thing about the side stand switch is there are no wires. The only connector I've found that doesn't have anything attached to it is on the opposite side of the bike. I think they were brown (chocolate) and black. I'll get to the bottom of it tomorrow. It's either gonna be the crack trigger, igniter, or a chewed wire. I'm getting closer, I can feel it. :)
Title: Re: No spark
Post by: FJmonkey on March 28, 2016, 10:42:31 PM
Quote from: twangin4u on March 28, 2016, 10:36:39 PM
The only connector I've found that doesn't have anything attached to it is on the opposite side of the bike. I think they were brown (chocolate) and black.

Might be the emissions connector, good for connecting other stuff that you want off with the ignition, my heated grips are connected via a relay by that connector...
Title: Re: No spark
Post by: Pat Conlon on March 29, 2016, 01:47:27 AM
You've got a workshop manual correct?
In the back is a wiring diagram color coded for your '84. Look at the color codes for the wires going to the sidestand switch. Look for those wires on the left side of your bike under the side panel.  There should be a plug connecting the switch pig tail to the wiring harness. If necessary, start at the igniter box, find the colors and work backward. You need to close that circuit.

Do the ohm test, not on the igniter box, but on the pick up coils that trigger the box (located on left side of your engine) do the test from the plug at the igniter box.
If either of those 2 pick up coils are bad, or the wiring thereto, you will get no spark to cylinders 1&4 or 2&3
Take off the side cover on the pickup coils, heat the coils up with a hair dryer, then test the ohm readings (again at the plug on the igniter box) You should see 149 to 182 ohms with the coils at 68* F

***Note that the test values shown in both the Clymer and Haynes FJ Workshop manuals are Wrong***

The Genuine Yamaha Service Manual (GYSM) shows the correct 149-182 ohm value
http://www.fjowners.com/index.php?topic=13448.msg135362#msg135362 (http://www.fjowners.com/index.php?topic=13448.msg135362#msg135362)