1987 Yamaha Big Bear Electrical Troubleshoot

[ResQ91]

Hi guys

My 87 Bear 350 won't start and could use a hand.

Turn key on and Oil light turns on and then slowly fades out. (I think this is key to this) No start, not even a tick.

battery and connections good

A Solenoid post jump turns it over

Neutral Safety Switch wire attached and seems good

It has not had a wire/switch on Rear Brake Pedal ever since I had it.

Any thoughts on some other things to troubleshoot this??

[Ajmboy]

If you jump the starter and it cranks, the batttery is probably good or ok to turn over. At that point, you may want to check wiring, starting at the ignition switch. My bet is you have a wiring issue or a bad or misaligned neutral safety switch. Is there a neutral light that comes on? Try holding the brake levers down when starting. 

[Mech]

Yeah, the fading light sounds like a dud battery but if bridging the solenoid cranks the bike over then it must not be the case.. In that case it's probably a bad connection somewhere. You could try turning the headlight on to see if that fades as well. Not sure what that would tell us at the moment without looking in the book but it would be a simple check of the battery.

I think I'd check the ignition switch as my first check.

The recommended thing to do is what's known as a "voltage drop check". In the case of the switch you put a volt gauge across the power wires on the key switch and with the key off it should show 12v, then turn the key on and the voltage should drop to zero as the power goes through the switch instead of the gauge. If it keeps showing a voltage with the key on then there's a bad contact in the switch. Some models have the 12v going through the cdi and then the  kill switch on the way to the start button so you should do the voltage drop test across those two parts as well.

Switches are a suspect here.. If not a switch, then a bad contact where a terminal connects to a switch or component, or where a wire crimps into the metal terminal on it's end.

[ResQ91]

So I just started tearing into wiring connections and found two w/high resistance.

 

Thought I had it.......

 

Got that squared away and find it was more than one thing.

 

What would cause difficulty getting to Neutral with shifter. (Won't start unless in neutral) Seems like if I rock machine back and forth it gets there.

 

TIA

[Mech]

Difficulty getting them out of gear if they were in gear when you switched off is quite common, and rocking the bike is the usual procedure.

Most bikes will start in gear if you have the brakes on well enough to make the brake light go. It doesn't actually need the brake light, it just needs the brake light circuit to be energised to bypass the neutral safety feature.

Edited March 12 by Mech