Neutral Safety Switch 1981 CBX

[budanddar]

Getting close to finishing the rebuild of my 1981 CBX.
It will not start and am going through the process of problem elimination.
Have the shop manual but cannot find the location of the neutral safety switch.
Any help would be appreciated.

Thanks,

Bud

[NobleHops]

Does it crank at all? If not, pull the clutch lever in and try again, report back.

[tevan]

Neutral switch is in front of the shifter.

[budanddar]

OK Nils, it cranks like there is no tomorrow.
Tevan, I see that little rubber boot in front of the shifter. It is connected to another boot that is on top of the crankcase.
Ideas on testing it? Thanks your guys.

[NobleHops]

The neutral switch prevents the solenoid from actuating, and so if it's cranking, that's not your problem. The coils have a black/white wire that is daisy-chained to each of them to power them and the plugs. Remove your tank and probe that for power (rotary kill switch and ignition ON), and if you find that you don't have any, trace the path of the black/white wire backwards with your multimeter till you find where you do and that will be your culprit. Check the fuses under the cover, not just visually, but with a multimeter before you do any of this. You can download a manual, including the wiring diagram here:

www.cbxclub.com/manuals

[budanddar]

Thanks Nils.......I am in Litchfield Park, AZ.
Ok, have 4 cylinders/pistons at - 125, 1 at 130, and a 150 psi on the compression test.
Have spark to each spark plugs and the plug wires are positioned correctly.
Neutral switch is working. Cranks well with the green light on. Put it in gear and the green light goes out. In gear no green light and no cranking.
Spark plugs are new and gapped.
I have that hydrolock vacuum system hooked to the carbs (1981).
Have fuel in the float bowls as I can drain them out. I was thinking of by-passing the vacuum canister on the back of the carbs and putting fuel directly into the two carb supply hoses.
The spark plugs are dry and no smell of gas.
I do not have the faring on but all of the wires with the exception of the 12 pin that goes to the head light.
The pipes are off as well.
After that...................?

[Kingludd]

Check petcock.

[budanddar]

Gas is going out the petcock and past the fuel filter. I am going to by-pass the vacuum device tomorrow and put gas directly into the two carb inlet tubes. Thanks Kingludd.

[NobleHops]

You have cracked the code here, you have air, and spark and compression, so it’s clearly carbs/fuel.

In gear the bike should still crank with the clutch pulled in, BTW, but that’s unrelated to your running issue.

That auto valve is quite possibly a culprit, but lets just test the silly stuff first - pull the hose off the petcock and then open it and see what we have for flow. If that’s bad (or you’re just too low on gas) that could be the issue - clogged petcock or just too low on fuel. If that’s good, then get a brass 5/16 barbed T connector and some 7mm ID fuel line and bypass that auto valve for the moment. It takes a surprisingly long time to fill the float bowls with an auto valve bike, and for that reason many guys (me) eventually ditch those permanently.

N.