My 85 GS450 quit running on my last ride

[dennco2]

At the start of the ride I noticed when I turned on the ignition ... the dash lights did not come on. So I turned off the ignition and back on again and all lights came on and the engine started, so I took off on my 10 mile ride. About 5 miles later I came to a stop sign and the engine stumbled and quit, but I was able to get a quick restart. A few blocks later, it quit again and no restart and no dash lights.

My riding partner got a UBER ride to get her van and return with jumper cables. While I was waiting for her to return I tried turning the ignition on again and surprisingly got lights. Then I tried again when she returned and got NO lights when turning the ignition switch to ON. After jumping for several minutes, my GS450 came to life again and I rode home with her following me. It ran fine for the 8 miles it took to get home, but I suspect I was mostly running off the power of the battery.

So now I am curious what is wrong with my bike? Bad ignition switch? Bad Stator? Bad R/R? Bad connections? I have a multi-tester but limited knowledge on how to go about testing the circuits. I will start the engine again (if it will) and test the voltage before and after starting to see if I get 14+ volts. If it is, I suspect the complete charging system is fine? Funky ignition switch that isn't making solid contact anymore? A new replacement switch available? Can someone in the group suggest what they think the problem might be ... or lead me to a prior discussion on this type of issue? A big thanks in advance for any help!

[glib]

At the start of the ride I noticed when I turned on the ignition ... the dash lights did not come on. So I turned off the ignition and back on again and all lights came on and the engine started, so I took off on my 10 mile ride. About 5 miles later I came to a stop sign and the engine stumbled and quit, but I was able to get a quick restart. A few blocks later, it quit again and no restart and no dash lights.

My riding partner got a UBER ride to get her van and return with jumper cables. While I was waiting for her to return I tried turning the ignition on again and surprisingly got lights. Then I tried again when she returned and got NO lights when turning the ignition switch to ON. After jumping for several minutes, my GS450 came to life again and I rode home with her following me. It ran fine for the 8 miles it took to get home, but I suspect I was mostly running off the power of the battery.

So now I am curious what is wrong with my bike? Bad ignition switch? Bad Stator? Bad R/R? Bad connections? I have a multi-tester but limited knowledge on how to go about testing the circuits. I will start the engine again (if it will) and test the voltage before and after starting to see if I get 14+ volts. If it is, I suspect the complete charging system is fine? Funky ignition switch that isn't making solid contact anymore? A new replacement switch available? Can someone in the group suggest what they think the problem might be ... or lead me to a prior discussion on this type of issue? A big thanks in advance for any help!

I had something similar happen just last weekend. I checked the battery and it was fully charged. It turned out that the negative battery connection was loose. I hadn't even noticed it when I checked the voltage. Too simple but true.

[BigD_83]

I had something similar happen just last weekend. I checked the battery and it was fully charged. It turned out that the negative battery connection was loose. I hadn't even noticed it when I checked the voltage. Too simple but true.

Had that happen when I first brought my 650 home. There was a minor vibration that kept backing the bolt out.

[John Park]

The fuse holder is another common culprit as the soldered contact tends to get corroded.

[BigD_83]

The fuse holder is another common culprit as the soldered contact tends to get corroded.

As are dodgy glass fuses. All good things to check.

[dennco2]

I finally got back to my 85 GS450 to check out the fine suggestions. The single fuse holder looked good ... but I removed the 15A fuse and polished up the inside brass clips and put back together. The NEG side of the battery was clamped down firmly. Then I opened up the head light bucket and pulled all the single connectors apart (one by one) to clean them and apply dielectric grease. One connector was a double green wires .... to a black wire I believe. Is that correct? I also noticed 2 single female wire connectors NOT connected to anything. Are they extra to allow future changes? Anyway, all the connectors in the bucket looked normal but I worked them over .... except didn't mess wth the multi-pin plugs. Should those be done as well?

Then I pulled the fuel tank so I could get to the 2 coils. Everything in there looked like caked on dirt ... so I pulled both coils off and cleaned all surfaces and the painted frame it attaches to. I figured I would get big improvement here as to lowering my electrical resistance.

I checked the idle voltage 11.99 volts ..... 12.35 V at 2,000 ..... 12.53 at 3,000 ...... 12.71 at 4,000. Then I checked the voltage after cleaning.

12.15 v at idle ..... 12.37 v at 2.000 .... 12.56v at 3.000 .... 12.57v at 4,000. Not much improvement! Should be 14.xx at 4,000 rpms, right?

Any suggestions on what to do next?

[hillsy]

Those voltage readings suggest there are bad connections in the charging circuit. Did you clean / check those?

Also with your erratic power I would think it's probably the ignition switch.

[dennco2]

Those voltage readings suggest there are bad connections in the charging circuit. Did you clean / check those?

Also with your erratic power I would think it's probably the ignition switch.

No, I have not cleaned those connectors. Probably should have done that first. Didn't check the voltage coming off the R/R. I'm learning as I am going along here. IF needed, I think I read in this forum that there is a superior R&R to the stock version?

I also think the ignition switch is suspect. Can that be cleaned .... or have to replace? If so, where to buy at reasonable price?

[cowboyup3371]

Yes, pick up one from a Polaris - SH775

[dennco2]

Those voltage readings suggest there are bad connections in the charging circuit. Did you clean / check those?

Also with your erratic power I would think it's probably the ignition switch.

hillsy, you are very correct about checking and cleaning the connections in the charging circuit. I pulled off the igniter and R&R units to clean the mounting points on the side plate. Then pulled the side plate to clean the 2 mounting points to the frame. Then I followed the wiring harness further back to the 5 bullet connectors tucked inside the frame and cleaned 3 connectors and 2 more which appear to go to the center stand.

I put it all back together and NOW I am getting almost 2 more volts out of the charging system!! Charged battery was at 12.76 V. Idle at 1,300 was from 13.30 to 13.93 V. 2,000 was as high as 14.60. 3,000 dropped down to 14.06 and 4,000 stabilized at 14.07 Volts. Big difference from before! Hopefully I have solved the charging problem so as to maintain the battery during a ride.

The other issue may be the ignition switch. It seems if I pull it out .... there are 4 connection points to clean? I would greatly prefer to keep the same key switch witch matches the helmet lock and the gas cap.

[dennco2]

Well, my gs450 electrical problems are still in there. I rode the 450 to buy a feeler gauge and magnet PU tool ... but only got half way and the engine shut down and all lights turned off suddenly. The key was still off as I pushed it off to a safe intersection in neutral. Then I heard the starter attempt to turn over the engine so I flipped on the ignition again and it started immediately. I took that as a que to turn around and attempt to go home. I got within 100 yard of home and it quit again!

I clipped on a multimeter and saw battery at 12.67 volts ... and only 13.70 volts with engine above 3,000. I flipped the ignition switch on/off several times and it came on each time while testing. Yet the ignition turned itself off on 2 occasions on my short trip ... despite the key being in the same ON position. Is it time for a new ignition switch ... or can the internal contacts in my old switch be restored/cleaned??

[hillsy]

You can pull the switch apart and clean it. Also check the wires going into the switch as there may be a break that is causing the circuit to fail intermittently.

[dennco2]

You can pull the switch apart and clean it. Also check the wires going into the switch as there may be a break that is causing the circuit to fail intermittently.

Will do as suggested .... when I get a chance and will report back.

[dennco2]

You can pull the switch apart and clean it. Also check the wires going into the switch as there may be a break that is causing the circuit to fail intermittently.

Okay, I pulled the ignition and lock switch off the bike (2 screws from the bottom) and then removed the lower end parts where the wires enter. It looked pretty grubby in there so I carefully cleaned all inside electrical connections. Almost lost a coil spring and ball ... but all is back together now and the ignition switch turns everything ON when I twist the key. Can't ride test it right now as I am waiting for some new valve shims. I hope this cleaning solves my sudden shut-off power issue now .... and the power only stops when I turn the key off.

[Eule]

I can't solve your main problem... but maybe I can make a suggestion about more minor mysteries.

One connector was a double green wires .... to a black wire I believe. Is that correct?

That was probably for your right front turn signal. One of those green wires is coming from the turn signal switch, and the other one is heading for the right turn indicator in the instrument cluster. The black wire is the one that runs to the right front lamp.

(The wires going to both right and left front lamps are black. It doesn't look weird on the left side, because the left turn signal wires coming from the rest of the bike are also black.)

I also noticed 2 single female wire connectors NOT connected to anything. Are they extra to allow future changes?

I am about 95% sure that's a "US vs the rest of the world" thing. In the rest of the world, motorcycles are either allowed or required to have a front parking light. Some of the GS450 wiring diagrams on BikeCliff's site show a front parking light on the UK versions of the bike; it is connected to a brown wire (hot) and a black/white stripe wire (ground). On the US versions, those two connectors are just chilling out, not connected to anything.

This seems to happen even on much more recent bikes. The other half also has a 2009 Y*m*h*, US version. It has a big reflector and lens for the front headlight, like you'd expect, but also a smaller compartment with reflector and lens above the front headlight. When you look at the back side of the reflector, you can see a mold line where there could have been a hole for a twist-lock socket for that small compartment, but it's just solid plastic. I think in other countries, there's a front parking light in there.