missing 650 Seca

When I rode my bike a coiuple of weeks ago, she ran fine. Now when I try to crank her she doesn't want to start, and would backfire (sounded like gunshot) through the right muffler (or so it sounded). I charged battery and got her to start up today, but ran very rough. Pulled #4 plug, seemed to make a difference. Pulled #3 plug, didn't make any difference. Seems like maybe the coil for the #3 plug isn't working, or possibly, the wiring is disconnected? I did remove and replace the bracket for the twin horns, is it possible I dislocated something in doing this? What should I check for?
Like others here, the electronics (especially electronic ignitions) is my weak spot. Any help is appreciated. I really want her on the road like she should be.

dave
Ace of Clubs

 

I'd make sure the Fuse Panel is upgraded. The Stock Fuse Panels are well beyond their usefulness and are a cause for a myriad of electrical and ignition problems.

I'd make sure the quick-connections to the wiring harness are secure, tight and clean of oxidation.

Swap the connections of your coils around and see it the problem shifts to a different cylinder. If so; suspect the Coil.

Trouble shooting an ignition problem starts at the Battery.
Battery fully charged.
Fuse Panel upgraded.
Coil connections tight and clean.
Ignitor connections tight and clean.
Ignition pick-up Coils dry, clean and tight.
Rotor face cleaned of oxidation.
Plug Gaps correct.
Resistances in ignition components at specs.

Carbs and tuning after the above are certified OK>

 

The right coil fires cylinders 2 & 3 so pull the plug wire on #2 and see if doesn't fire also. If it does then it is not the coil. I would then check the plug cap for the correct resistance (5kohms) and also look at the wire end for any signs of arcing. If you see and then trim about an inch off the wire end and reinstall the plug cap.

 

It was running fine just a coiuple of weeks ago. Haven't ridden it since, but now it has this problem. Just wondering where I need to look. Also...is it possible to use some other coils for this bike? Do the coils from an FZR 600 or a YZF 600 work? They are newer and (probably) in better condition.
I know I sound like a moron, but most of my mechanic time has been on old Harleys. Inline fours are kinda Greek to me.

 

check your connections and listen to what Rick has to say. He has saved me more time than I can think. I had my maxim x running (the one I am fixing, not the one I am restoring) just the other day and then it wouldn't fire at all. I had no spark, at all. Kinda bothersome. So, I took a look at my connections, and lo and behold they were that aqua color (especially the side stand relay). After a good cleaning, the bike fired with no problem, until today when I had the same issue. Turns out, the side stand relay wasn't keeping a good connection due to a broken tab. A zip tie fixed that and now she purrs nicely.

 

bluzglide, with all your experience, did you ground the loose plug lead, let it spark, or insulate it (bad) ???

Off topic-- I just welded brackets to my frame and I lost 2 & 3. What did I just fry ???

Did I fry my right coil or part of my "pickups" or the "brain" ??

I got parts bikes !!

 

You should have pulled the Ignitor and the Voltage Regulator off the Bike before you do any welding involving striking an arc.

That Caution is in BOLD Print in ALL the Workshop Manuals.

There's too great a chance that you will fry some Board or the Rectifier.

 

Just tested the Ignitor. Runs on 1 & 4 with either, and I know both Ignitors work.

So, folks, is it a fried coil or the pick-ups under the left cover?

Can I try using the good "turbo" coils or are they "special, turbo only"??

 

Test the Coils by swapping-over the two connections to the wiring harness.
If the formerly missing Cylinders fire and the two that were firing miss ... you need a Coil.

Don't forget ...

There are Parts on these Old Bikes that have been working for 20-Years or longer that aren't designed to go that distance.
Fuse Panel
Alternator Brushes
Starter Brushes
Coils
Wires

That's why they are offered to us inn the aftermarket. Some just hang-on longer than others.

 

Rick, the connectors that I have pulled (input for the coils) are that oxidized grey color. Could that be a reason that mine doesn't want to fire?

 

One good reason!
That's where they get +12V from. If there are dirty contacts the resistance can be enough to weaken the spark or cause a misfire.

 

That will be my first attack tomorrow then. The contacts are really dull and look like you could wipe some of the oxidation off with your finger. After that, I'll check the coil resistance and see what the spark looks like at the plugs.

 

Well, rick, mine went to 0 , nothing , nada , no spark. I might be looking at the mess of wires that were in the headlight housing, or I fried the "points" pick-up coils, or, has anybody had a progressive ignition failure???

Hey, my V-Star still runs !

 

I have not heard of an Ignition "Progressively" getting worse. It usually either works right or goes South ... Bingo -- No Spark.

Intermittent happens a lot. That's been traced to any number of reasons for the System falling below the needed power to run the bike, the old fuse panels, loose wires, and dirty contacts all over the bike.

Oh, yea ... and too short Alternator Brushes!