Help.... will not run

[cookieman]

Hi, maybe someone has an anser for me. I have an 84 venture that will not start!!!

I repace the tci and it ran, I had to work on the carbs--- ok did get running, but I went to start it to finish setting the carbs and...... at one time it was like the 4 of july.

 

Here's the stange thing I have 12 volts going in to the tci red wire just like should, but I start cranking and the voltage goes down to 3.68 volts on the red power line-powering the tci!!! I have checked all the ohm reading and they are ok, all the relays are working.

 

I follow the diagram and it shows red line 12 volt all the way to the tci, I know the wiring route on the bike is noware near the drawing on the paper(I found that the stater wiring goes thourgh the turn signal relays and other things). I just can't get 12 volt's at the red power ine.

 

Has anyone else had anything like this show up. Thanks any help would be appericated.

tom

[bongobobny]

Does the red line drop at any of the other points as well, or just at the TCI??

[buddy]

You said like the Fourth of July??? as for sparks or what?

Does the engine turn over? or what?

We Need more info.

 

Several things can keep it from running. (Side stand switch) bad - (pigtail for pickup coils) bad connection - (kill switch) contacts acting up. (fuse) goes weak when under load. (ground wire or hot wire) loose or weak connection.

[Venturous Randy]

Check the resistance on the wires going thru the sidestand switch.

Ask me how I know this!

RandyA

[Dano]

First thing to do is check your battery voltage when you are cranking, then follow your wire to its end. This way you can check all points.

 

Dan

[6m459]

I repace the tci and it ran, I had to work on the carbs--- ok did get running, but I went to start it to finish setting the carbs and...... at one time it was like the 4 of july.

 

Sounds like you are working on two things at once. I never like to do that, one problem at a time keeps the detective work more one dimensional when things go wrong. One of my cardinal rules.

 

Where were the 4th July sparks coming from? Wiring, carbs ? Which wire, which carb? More info please.

 

Brian H.

[bcradio]

Drops are caused by two things provided the battery is good: high resistance on the wire route, and high current draw on that line (accordingly).

 

Give me a minute and let me look at my schematic.

I get right back.

KB

[bcradio]

Good call randya! I don't know what exactly is in the TCI but the sidestand status line goes right in there - since it's a safety input, no reason it couldnt cause problems.

 

On the schematic the line going to the TCI r/w wire comes right off the ignition switch on what is the ignition "on" voltage source, through a 15 AMP fuse and the engine stop switch (handlebar). I would do this: Let's ALWAYS remember safety and how much we all don't want to burn our house down. Using a 15 amp fuse inline with a piece of wire (we'll call it "test"), tap the r/w wire on the TCI (maybe the connector) and then turn on the ignition and connect the other end of the "test" wire to the battery positive and try to start the machine. If this works the key switch is bad. If it doesn't work then the problem is going to be in the TCI/coil circuit. Under these conditions, if the wire doesn't work it will be nice to know the voltage at the r/w wire during start.

 

If this doesn't work, then I would begin unplugging one coil at a time until I was sure one wasn't shorted. If you want to measure the primary resistance on the coils, it is listed as being 2.7 Ohms.

The secondary coil resistance is listed at 13.2 KOhms.

 

Oh and GROUNDS are critical: the testing meter should be connected DIRECTLY to the ground side of the battery. Measure the resistance between the ground of the battery and the frame as well; a problem here can cause all kinds of otherwise unexplainable problems.

I had to re-do all the frame grounds on my '84.

 

This is all assuming a TCI problem, be sure to check for spark.

 

Please repost your progress.

 

KB

[bcradio]

One more thing: if there are "sparks" coming from the carburetors, run away! The carbs should be at ground potential, or close to it. They aren't really bolted to the block because of the rubber boots but there are enough cables to keep them close to ground. If the carbs have been literally "sparking" then ground them while you're working on them! Spark + gasoline = fire.

 

The ONLY spark on your bike is supposed to be contained in the cylinders.

 

KB

[cookieman]

Ok maybe I didn't get the detail right. 4 of july I ment the back firing, and caughing though the carbs.

The red 12 volts drops to 3.68 during cranking, on all 12 volt power for the coils... and the power line for the rectifler, but the battery drops down about 1 or 1.5 volts during cranking!!!! Everthing with starting the bike goes down on voltage. The rear tail and brake light are not affected. Therefore with everthing else being good, I am wondering what is causing the voltage drop. I also get this drop with the plug in plugs out of the tci.

When I say red-- I mean the main red wire that carries the 12 volts from the battery or the brown wire that comes off the rectifler, (which also drops to 3.68 volts during cranking).

With the voltage droping this low I have never seen any eletronics work.

At one time, I did not have any trouble starting and didn't have any problems ecept the carbs.

I am think I have trouble in the one relay area called the central processing assembly, it's the one larger relay box with the chips in side. All the other stuff seams to check out.

But who knows I could be wrong? Thanks guys let me know what you think tom

[bongobobny]

OK a starter motor DOES put a heck of a load on the battery but I'm not sure it puts that much. Does it crank over at regular speed or does it seem slow?? Sounds to me like it may be new battery time...

 

Of course you could have a dirty ground on the battery cable, or a bad solenoid, or corroded + contact somewhere. One big culprit is those yucky fuse connectors. Read directly across the battery and get back to us!

[ventureohio]

I just sync'd my carbs and had the breather box out. Right under the battery, my connectors were corroded to beat the band. wasn't having any problems but if it had gotten any worse, who knows. Just saying that is a hard one to find if you don't have the breather box off.

[Condor]

No battery should pull down to 3.? volts while cranking. Sounds like you have a weak battery and possibily a stator that isn't putting out to keep it runing????

[skydoc_17]

Hey Tom,

Where in Pa. are you located? If you are close, I have a brand new battery in the box, I could come by and we could put the new battery in and see if that takes care of your problem. Plus, we could take a look at those carbs.

Earl

[cookieman]

Thanks all!!!!! GUESS WHAT this after noon went to move the bike and just for the hell of it, I turn on the key and hit the starter and SHAZAMMMM this GD bike kicked right over and purred like a kitten, (well I always said kittens make good target pratice NO JUST KIDDING) I couldn't beleve it. I did get to watch the voltage and didn't drop!!!

I am still on the look out for the special relay tha has the chip in it.

 

Thanks again. I live in the pittsburgh area, anyone going to johnstown thunder in the valley this year. I make there and used to spend the night at seven springs and come back sunday. I don't think I will be staying this year, because all the other guys now are taking their wives and getting kind of costly. tom

[GeorgeS]

Is this a High Mileage Bike??

 

The Heavy Internal contacts of the Starter Solinoid, are probably mostly fried.

This will add a high resistance in series between the Battery and Starter Motor.

That will cause a large Voltage drop, Now the voltage to All other Systems, ( ignition system included ) will be low.

 

Your not out of the woods , your problem will come back.

 

Also, Clean and resolder the Studs on both ends of the battery cables. Check the main ground point at the rt. fwd corner of the Engint lower case.

 

However, if battery is over 3 years old, it is Very Suspect, of an Internal Intermittant Short .

 

Also check the Plug between the Stator, and the Rectifyer/Regulator Unit for Burnt Pins ( a common problem )

 

 

 

Electricity is an Incidious Thing !!! Its haunted me all my life !!