79 sputtering/backfiring/bogging

[MadAdventures]

It's arcing from a small dry rotted spot on the side of the sparkplug cap.
I checked the resistance, and it is at the normal 5k.
I've got the day off and I'm determined to fix this today, so I'm gonna try some electric tape and see how that works.

[MadAdventures]

The positive and negative terminals on the battery were hot enough to burn me, and the bike wasn't started at all. It was on for a bit, as I was trying to crank it, but all I did was try to crank it, it didn't crank, so powered it off. Anyone know if that has anything to do with it?
By the way, I currently have it hotwired, because I lost the keys.

[MadAdventures]

It's definitely heating up when the bike is powered on.

[3Phase]

MadAdventures,

You need to be very careful or you're going to get a face full of acid and a hot battery shower.
An engine not starting and hot battery terminals is serious and if it's a short circuit anywhere except the starter motor then it really should have popped the Main fuse before the battery terminals got hot.

After you check and tighten the battery terminals you need to divide and conquer to find the problem but do not leave the ignition switched on!


Unplug the Green wire on the starter solenoid from the Red/Yellow wire at the wiring harness or just take it off of the solenoid and then with the ignition switch off and the transmission in Neutral you can use a screwdriver or something similar to jumper the two starter solenoid terminals and see if the starter motor turns. The Green wire--Red/Yellow wire is part of the ignition ballast resistor bypass circuit and basically hot wires the engine while the starter solenoid is operating or jumpered so the engine can and will start if you don't disconnect Green wire. Yes, the engine will stop when you remove the jumper but it's scary as ffour horsemen if you're not expecting it to happen.

If the starter motor turns normally and the battery terminals stay cool while you jumper the starter solenoid then it's time to remove all of the fuses.

Turn on the ignition switch and check the battery terminals. If they're still heating up then there's a short somewhere between the ignition switch and the fuse block.

If the battery terminals stay cool then put the fuses back in one at a time until you find the the circuit that makes the battery terminals heat up.

And once more so it sinks in:
You need to be very careful or you're going to get a face full of acid and a hot battery shower.
An engine not starting and hot battery terminals is serious and if it's a short circuit anywhere except the starter motor then it really should have popped the Main fuse before the terminals got hot.

[MadAdventures]

Thanks for all the advice! I'm gonna go do these things right now, and I'll reply back when I'm finished!

[MadAdventures]

I tested it, the starter motor turned over, and the terminal got hot. I was gonna test it a second time, but hot wiring it does nothing now. Does that mean that the connection from the positive terminal to the starter solenoid is bad?

[TopCatGr58]

I'm sure Scott/3Phase will chime in soon, but heat on connections can mean 2 things.
1.) There's too much corrosion between the connectors, and too much current is trying to go thru too little contact area causing resistance which causes heat.

2.) The connections are in good clean condition, but the starter is possibly shorting even though it's turning....which is causing it to draw too much current thru the wires/connectors...which again causes resistance to develop heat because it can't handle the amount of current trying to get thru the connector. The battery can provide 300+ cold cranking AMPS. The starter should provide a proper LOAD to the current flow, and so it should only draw something like 50 amps, but if it's shorting internally, then it's providing a direct current path from the battery to ground without much or any LOAD in the way, and so ~300 amps tries to flow thru the wire=heating up the connector!

T.C.

[MadAdventures]

One of the terminals on the starter solenoid, the one that connects to the positive terminal on the battery, was so rusted, I broke the screw, trying to get the nut off.
I'm thinking that must be the problem with the battery terminals getting hot. Do you think that could cause any of the problems I started this thread for? Sputtering/bogging at 1000rpms with a major loss of power, and no idle?

[MadAdventures]

Is the terminal on the starter solenoid repairable?

[3Phase]

I had a dentist appointment, then went phone shopping with my little brother and now I has a new tablet.

The start solenoid is sort of repairable, it depends how much work you want to put into it and what kind of tools you have. It might be better if you took it to the local auto parts outlet and matched it up with another solenoid, or you could get a used solenoid from eBay but then you have to wait.

From what you've described I think you have a bad starter motor. If the problem was just a rusty solenoid terminal then the rusty terminal would get hot because it's a rusty resistor but that wouldn't heat up the battery terminals.

It's not difficult to check the starter but it's not fun to clean and repair. If you don't have a ammeter then you might be able to get the starter tested at the parts house or they may have a meter you can rent or buy. One of the inductive meters that you just set on the wire when you crank the engine works fine.


Lessons In Electric Circuits -- Volume I
Chapter 8
DC METERING CIRCUITS

[MaximPhil]

Thanks for the link 3Phase,
I am still confused ..but on a much higher level
Seriously a very informative read for those who care to see behind the curtain of Electrickery. I did not see any mention of the "Magic Smoke" perhaps that is in Chapter 2

MadAdventures Good luck with your electrical gremlins. You are in good hands.

Phil

[MadAdventures]

I will be trying to replace the starter solenoid today.
The starter sounds good. It turns over nicely. I will check it though.

I suppose I need to check my wiring for a short, which I also something I'll work on today as well.
Will reply back later today

[MadAdventures]

I appreciate the helpful replies!
How would I determine if my starter is what's shorting out?

[HalfCentury]

You have to measure the current being drawn by the starter. The starter can operate properly while drawing 2X or 5X or 10X the normal current of a "good" starter.

My favorite quotation is from Lord Kelvin

I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.

[DiverRay]

An easy way is connect your VOM to the battery, and then jumper the starter and see what the voltage is at when you do that. IF the battery voltage drops below 11.5 Volts, you have a weak battery or a bad/dirty starter. If it drops below 11V., your bike will not start.(actually about 10.5V)
The starter is easy to remove, and not that hard to clean up. remove the 2 10mm bolts that hold the plastic cover on and the 1 10mm bolt holding the starter. Remove the wire from the oil switch, and pull out the starter.
2 long 10mm bolts hold the starter together, remove them and CAREFULLY remove the back end/cover.
You can then clean all the old grease and put in new. I also chuck the armature in my drill press, VERY CAREFULLY, and put crocus cloth on a flat file to clean off the contact area of the armature.
Re-assemble with new grease after measuring resistance of both stator and armature and your done.