'80 GS450 twin, electrical issues

[koolaid_kid]

I suggest having the battery tested. It may be at full voltage but not be able to supply enough current to turn the starter. You could also run the same starter test using a car battery. It should do a lot more than just click.

[apopleptic]

FWIW: this is the bolt I have as my engine block ground. Fairly inconvenient to get to, but if you put the bike on the center stand and approach from the right side of the bike from right near the center stand you should be able to get a 10MM socket on there and take it right out. Remember that the connection from the block to the battery is the only ground for the starter. That being said, a bad battery is a deal breaker. I like to keep a jumper pack for my car which can be handy in such moments.

[Trevor76]

It was the battery. Stuck a new AGM Bikemaster in last night and lo and behold the starter motor jumped to life when I ran a lead to it from battery positive.

Now, if I could only get the carbs back in. I have the air filter free from all the mounting points, the electrical plate off, and all of the wiring out of the way...
and still having a devil of a time getting the carbs to slip back in. I'm sure it would be easier with an extra set of hands but I don't have anyone around at the moment to help. Anybody got any tricks to get them back in there? I have tried WD-40 on the manifolds but I'm really not even close to getting everything lined up. I'm going to post in the general maintenance section as well, hopefully I'll get some answers by tomorrow when I have time to work on the bike again. Today I was robbed of "bike time" as I spent my afternoon replacing the passenger window of my Honda Civic. Some crackhead busted it out and stole my radio. The kicker is that the door was unlocked.

[apopleptic]

It's hard to describe how to squiggle them back in. If your boot's are too old they shrink and make it harder.
The engine side I approached from the bottom and levered them in fairly easily. I ended up using a crowbar and a wrench to leverage the airbox side in. I use regular oil for lube. seems to stay slippery longer than wd-40 and easier to apply by fingertip.


Edit* Also great about the battery!

[pete]

Glad you found what it was! That will make everything else so much easier here on in...

Bugger on the window though, that really sucks!

Your carb boots sound like my old ones, which means you need new ones. That's the only real true answer to your problem.

You can work around the hard old ones but they won't seal properly and will give you grief.

I used rubber grease to get my carbs on the old boots but my first start showed the hanging idle real bad which is air leaking in there, so I now have brand new ones that are night and day difference. They're extremely supple, have a larger outer and smaller inner diameter to the shrunken hard old ones, yet it is extremely easy just to slide those carbs right on in, no need for rubber grease or any sort of lube...

[Trevor76]

The carbs are back in, turns out that the boots were plenty soft enough. I just had to get the correct angle and keep the airbox out of the way. Would have been easier with a helper.

Everything is wired in, and the bulbs behind the tach and speedo have been replaced. I couldn't find those bulbs anywhere so I had to order them off of Ebay. I got a ten pack, they are actually Stanley vintage bulbs in a little slide-out box.

I can see how an LED upgrade would be nicer though.

Also I put in new brake pads and replaced the stock bleeder screw with a speed bleeder.

Now the turn signals won't work and I can't figure it out. Everything seems to be wired in correctly.
It is possible that the flasher relay is at fault, but it worked fine a couple of weeks ago before I tore everything apart to put in the new starter motor and battery.
Every other light is working fine -headlamp Hi/Lo, brakelight, and gauges.

I'm probably going to kick myself when I find the problem as it is likely something stupid.

[Trevor76]

SUCCESS!!!

I had been trying to repair my run/kill/start switch for a couple of weeks, with no luck.
I haven't had the time or money to do much else. Finally I broke down and bought a "new" one from a 1982 GS550 and modified it to fit the '80 450 harness...It works!

I got the bike running this evening, still needs a lot of little things done to it before I can take it for a spin but it was nice to hear it running.

I need to:

hook the throttle cable back up

solve the turn signal mystery (they still won't flash)

put the mufflers back on-the hardware that was on the bike (holding the headers in place) is pretty shot. I want to replace all four bolts, anyone know offhand what size they are?

adjust the clutch and front brake

There's some more stuff I can't think of at the moment, or haven't realized yet, but the bike is running and that's the important thing. I pretty much just wanted to have the satisfaction of knowing that I had put it back together right before having to get it ready for winter, which is nearly upon us. If I can get it out for a spin around the neighborhood, all the better.

Once I can get back to it I will take some tests to make sure that the reg/rec and everything is functioning properly, I'll have to consult the stator papers for a refresher on how to go about doing that...

Anyway I'm pretty pumped, just wish I had gotten it done sooner.

Thanks for all of the help guys!

[pete]

Great news Trevor! Very glad to hear it

As for your indicators, I had two different reasons for mine not working initially.

First was too low a voltage when I was trying to test them with an old PC power supply.

The second was the ground for the indicator circuit wasn't connected as I hadn't gotten that far along cleaning up the harness yet.

Once I grounded it and used a car battery, all was good

Of course it also could be something simple like blown bulbs or a dodgy indicator relay...

[Trevor76]

Hey Pete!

Bulbs are not burned out, I just verified that yesterday by hooking them up directly to a battery one by one. It could conceivably be the flasher relay, is there any way to check the relay off of the bike?

Referring to the diagram that Apopleptic uploaded, where is the indicator circuit ground that you mention?

[pete]

More than likely the relay, but as for testing it off the bike I'm not sure as it needs the load of the indicators to flash.

There's a point, you haven't replaced your indicators with LED types have you?

As for the ground, I'll need to look at the factory manual again. I just checked the Clymer which I have in PDF format but can't see it...

[Trevor76]

No LED, and the weird thing is that these were working before. Probably the flasher but I want to explore all other possibilities before spending the cash for a new one.

[pete]

That makes sense, I'll try to get a look next time I'm in the garage, but from memory it was the one hanging off the same branch of the harness as the rear brake light.

[apopleptic]

Everything is wired in, and the bulbs behind the tach and speedo have been replaced. I couldn't find those bulbs anywhere so I had to order them off of Ebay. I got a ten pack, they are actually Stanley vintage bulbs in a little slide-out box.

FWIW These bulbs are available anywhere and are pretty much the same as the ones under the speedo and everything. They're working in mine now. I'll try to catch up more and see if I can figure out anything else for ya, but I just finished driving 14 hours today and I need to take a rest. Good luck!

[pete]

That makes sense, I'll try to get a look next time I'm in the garage, but from memory it was the one hanging off the same branch of the harness as the rear brake light.

Ooops! Forgot... completely... was in there for hours today... and another hour or so tonight...

[Trevor76]

Still no luck getting the signals to work so I ordered a new relay from a vendor right here in Columbus. Hopefully it will be here tomorrow as I have the night off of work and will have an opportunity to plug it in.

This past weekend my buddy stopped by to hear the bike run, and after hooking the battery up I couldn't get it to start again. I rechecked all the wiring but can't find the culprit. Very frustrating. When I checked for spark I got nothing, leading me to believe that the issue lies somewhere between the ignitor, the pickup and the coils.

The battery was fully charged, it had just come off of the battery tender so that's not the issue.