92 Katana - No Spark

[Vodka]

I just purchased a Kat - non runner with no spark.
I removed the carbs because they always need cleaning when they sit that long and I need some help to get some spark.

A few days ago I had some dull/dim but blue spark and when I tried to run the bike after installing the carbs I didn't hear it fire once.

So here I am now removing the plugs and plug wires and checking for spark again.

I tried checking ac & dc voltage off the alternator and I got nothing but I may have been doing it wrong now that I have read more.

Next time Im checking from the red wire to ground if I have any voltage generating but besides the point


It could be the pickup(s?) on the crankshaft. its probably not the Ignition Coils.

What else is there to check.

Does the AC Generator produce the signal and power going to the coils also or does that come from the battery? e.g. bike will run without an alternator albeit not very long

Also my carburetors had a couple issues...

The 2 jump tubes by the vacuum/cv slides in between the outside and middle carb are 'rotted off'
They Tee into both carburetors but the ends where a hose should go has rotted out. It is like a Tee.

http://www.bikebandit.com/oem-parts/1992-suzuki-katana-750-gsx750f/o/m147858#sch259319

hose #6



Also missing the spring adapter that goes over the needle so the spring isn't pushing on the slide
Part #8 on the picture

http://www.bikebandit.com/oem-parts/1992-suzuki-katana-750-gsx750f/o/m147858#sch278352

part # 13382-42A00

Then I found under the pilot air screw that one of the rubber washers was missing where the spring, then a small metal washer sandwiches in between the carburetor.


Just an observation.

[shpielers]

Hey man, welcome to KR!

If you haven't found them yet, there are a couple things to go get in the wiki (link at upper left) a service manual, and carbs 101. Carbs 101 is a detailed how to for carb cleaning. Seems like this isn't your first rideo, but more info can't hurt.

It's common for these bikes to get low voltage to the coils. A popular mod is the coil relay mod. It bypasses the old wiring harness and puts juice straight from the battery to the coils. While this isn't a substitute for properly checking voltages along the harness and fixing where appropriate, it's a good temporary solution. If you're good with a soldering iron and have parts on hand, shouldn't take more than an hour and a half to put a coil relay together. If you get that hooked up and still have spark issues, that narrows down things considerably.

FYI, you're supposed to get at least 10v with the engine cranking when measured at the coils or you'll have spark issues. So I should have led with measure voltage there 1st and if it's low try the relay mod, or go through each connection on the harness and fix/clean when you find voltage drops.

[Vodka]

Ahh thanks for the reply! Not my first rodeo but everything's different when you switch brands. I'll look into the coil relay mod and I was dloading the service manual when I posted this thread! I'll get back to you my findings. I did unseat some connectora and redo them and I'm getting blue spark buy still my plugs are getting wet now and no idle has occurred.

[92xjunker]

Blue spark is a good spark. Orange is a weak spark. Check the voltage feeding the coils while attempting to start, 11v+ needed for a good cold start. How old are the plugs and fuel?

[Vodka]

http://katriders.com/wiki/index.php5?title=Carbs_101

http://katriders.com/wiki/index.php5?title=Service_Manual

Found those !

and this

http://katriders.com/vb/showthread.php?t=116991

I got a friend who is into wiring and he has those relays laying around. He has a series of two of them together that he does funky stuff with in car installs

[shpielers]

Blue spark is a good spark. Orange is a weak spark. Check the voltage feeding the coils while attempting to start, 11v+ needed for a good cold start. How old are the plugs and fuel?

Shit, it's 11v? Oops, my bad.

[92xjunker]

10v will get it started, just not so quickly when cold.

[Vodka]

If I did it correctly today...

The voltage on the orange wire at one of each of the coils to ground drops to 6-7V While cranking


Oah yeah - 3 BARK plugs are new other than yesterdays wet-gassy issue, theyre dry now.
I flushed the fuel tank and the fuel inlets have filters in them. The old stuff in there was cloudy but not rusty or full of water/moisture when I emptied it into a glass bottle
I always keep my fuel cans sealed with no contaminates and less than a month old.


With the low voltage, it seems like the bike will fire as soon as you push the [starter] then it peters out and just keeps cranking over.

Almost had it running yesterday but then the lighting fuse blew ( 10A ) because I had the charger on the battery while I started it... ZZzzzz

[92xjunker]

6-7v is no bueno, was the battery fully charged? 11v+ needed for good spark. If the battery is good and charged, I would start cleaning all connections and use dielectric grease on them, including the switches before you do the relay mod.

[GSXFJim]

A battery can hold a +12v charge but not have the amperage to turn the starter and power the rest of the system, have it load tested, altho if your dropping to 6-7v on start.... time for a new battery

[Vodka]

Battery is new last year for my other 750cc bike, sure the CCA might be down a little but I know it does well in anything I put it in.
I got the bike cheap because it was doing this.
Didn't come with a battery.
I'm pulling the igniter cover today to check that out

[92xjunker]

Low coil voltage and over fueling maybe your problem.

[Vodka]

Is the igniter rotor supposed to be oil bathed?
Nice looking melk oil there, its super synthetic oil

[92xjunker]

????? Milky oil.... Not good. Yes, oil is present there. There is a drain hole on the lower right side.

[shpielers]

Holy crap that doesn't look good. Looks like water got mixed with your oil somehow from that pic. Ewwwww


Mine's never had THAT much oil there...