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, 2024 by Mech

[mga]

On 3/11/2024 at 11:34 PM, Mech said:

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.

 

true about rocking the bike. I've had a few times that i could not get it out of gear. bot, being a 24 year old bike, i don't expect it to run like new. These days i just use it to spray the yard, or to save me a long walk down and up the hill out back.

[Gwbarm]

I have aa 2000 big bear and have some of the same problems you are describing, hard to get out of gear and the neutral light is iffy. Sometimes i can get it out of gear i know its not in gear i can roll it and the neutral light not on, other times neutral light comes right on. If you go all the way down with the shifter and then come up just a hare not too much or you will be in first, just a tickle, like cracking a safe, if still not out of gear try again. I have just kind of written it off as worn gear box and havent really tore into it to fix it. I can pull the break lever to get mine to start and just go from there, if i get tired of trying to get neutral light to come on, i can get it in neutral, but if light is not lite it wont start until you pull the brake lever. Yours might not be this bad but the one i got was heavily abused and neglected and im gradually bringing it back to life, as soon as i think i have it something else pops up.

[mga]

seems the older big bears have the same problem: getting it back into neutral unless you rock it.

I have to do that to mine once in a while, but not too often, it's still a PITA

[Mech]

If a bike doesn't want to come out of gear and into neutral, the easiest way to get it out is to blip the throttle so the bike starts to roll, and then as you throttle off and the load on the gears from driving the bike comes off the gears, they will generally slide out of mesh.

Works on two wheels, quads, and 4WD trucks stuck in 4WD.

[Gwbarm]

Thanks for the tip! The Big Bear is the only one of mine im having this problem with, the Suzuki shift all the way down and neutral light comes on, Big Bear same shift pattern all the way down doesnt come on but it in neutral because i can roll it, i have to lift a tad on the shift petal to get the light to come on.

[Mech]

Thought you'd know that technique from old two-wheelers Gw.

[Gwbarm]

I did used to have to do that fairly regular on the 60s bikes with the 1 down and 3 up trans, neutral is in between 1st and 2nd, but with ATVs all the way down is neutral and it does go into neutral because i can roll it but the light doesnt come on, so im thinking it may not be completely in neutral, so im going to try to blip it and see what happens.  

[Mech]

Yeah good point about first being at the bottom, that does make it much easier to find neutral. And yeah, it was those old machines I was thinking of. I still always try to slip things into neutral while It;s still rolling if it's convenient, or blipping the throttle before putting things out of gear if they are reluctant.

I don't know about the yamaha switches but I've seen hondas and suzuki with worn switches that behaved as you say. Sometimes jiggling the shift lever with your hand just enough to make the shift barrel move a little makes the light flicker.

Edited June 21, 2024 by Mech