Topic: Neutral light on in 5th gear.

[Mingo]

My neutral light comes on in 5th gear--sometimes. It kind of flikers on and off, and at times it just stays on.

Anyone know why?

Also, the bike bogs and sputters with loss of power at about 5K RPM.

In first and second, it bogs at about 5,500.
In third, it bogs at around 5000.
In fourth and fifth, it bogs at 4500.

Anyone know why?

[Stev-o]

What bike?
Stock??
When last tuned???
Just started bogging?

[lucky]

I sure would be checking that neutral light. Just to make sure the wire is not grounding on the engine.

[Mingo]

What bike?
Stock??
When last tuned???
Just started bogging?

Right, forgot to mention: 78 cb750. Kerker exhaust, stock air box. New plugs, timed, valves adjusted a couple of weeks ago, when I bought it.

I don't know anything bout the carbs yet. I was hoping to wait until winter to rebuild them.

[Mingo]

I sure would be checking that neutral light. Just to make sure the wire is not grounding on the engine.

Lucky, could you advise me on how to do that?

I took the light case off and checked the back. It all seems fine. No obviously broken, or shorting wires.

I looked inside the headlight bucket, but when I tried to check continuity between the Neutral wire posts on the light case I found that pretty much everything in the headlight bucket showed continuity with the neutral switch. I just don't know enough about electronics yet.

What steps would you take to check the neutral light?

Thanks.

[Mingo]

Also worth noting, maybe, that My clutch perch broke, so I bought an after market perch and just shorted out the circuit that keeps the bike from starting unless the clutch is pulled.

[Stev-o]

Ok, that's what we needed. Old points/condensers? Should have done full tuneup to rule out such items. All cylinders firing? Touch your header when running with a wet towel.

If yes, sounds like carbs. Drop a float float bowl and look inside.

Report back.

[scottly]

The K8 carbs have the drain screws instead of the drain plugs. The fuel level inside the float bowls can be checked with the clear tube method, by replacing the hoses at the bottom of the float bowls with clear plastic tubing and loosening the drain screw. I would check that before removing the float bowls.
As far as the neutral light, the switch is on the bottom of the motor. Try disconnecting the wire, and if the light still comes on, the problem is not in the switch itself. It may be related to the modified wiring. Just make sure the bike is in neutral, and/or the clutch is pulled in before hitting the starter button.

[trueblue]

Check your advance mechanism too, it is behind the points plate. If you're not getting full advance it will bog and splutter around 4500 and 5000rpm.

[bollingball]

scottly looking at the print I can not tell if that sw. is NO or NC. How does it work is it made when in neutral? Or made in gears 1-5 and not made in neutral? Does anyone know? Guess I'm going to get on the floor
Ken

[scottly]

The switch is closed in neutral, open when in gear.

[750K]

My 77 had a similar neutral flicker, the switch is on the bottom of the motor on the shifter side of the bike. I undid the screw holding the wire, cleaned the wire lug and the connection at the switch. When I screwed it back in I snugged it tight and the switch turned in a bit, tightening up in the pan. It solved it, no more flickering or constantly on in 5th gear.

[lucky]

Also worth noting, maybe, that My clutch perch broke, so I bought an after market perch and just shorted out the circuit that keeps the bike from starting unless the clutch is pulled.

That is the reason the neutral light is flickering. The switch on the clutch perch and the neutral light share a common wire. That light green wire.
Look at the wiring diagram in the Clymer's manual and you will see how they are interconnected. Fix the clutch perch and that wire for that switch and the neutral light should stop flickering.

No need to mess with the neutral light actuator on the bottom of the engine.
Just a chance to get an oil leak by messing with it.

[Mingo]

Also worth noting, maybe, that My clutch perch broke, so I bought an after market perch and just shorted out the circuit that keeps the bike from starting unless the clutch is pulled.

That is the reason the neutral light is flickering. The switch on the clutch perch and the neutral light share a common wire. That light green wire.
Look at the wiring diagram in the Clymer's manual and you will see how they are interconnected. Fix the clutch perch and that wire for that switch and the neutral light should stop flickering.

No need to mess with the neutral light actuator on the bottom of the engine.
Just a chance to get an oil leak by messing with it.

I simply followed the cable from the clutch perch into the headlight bucket and crimped the two wires together (there were only two wires in the cable), then covered the crimp with shrink tubing.  What else do I need to do?

[Mingo]

My 77 had a similar neutral flicker, the switch is on the bottom of the motor on the shifter side of the bike. I undid the screw holding the wire, cleaned the wire lug and the connection at the switch. When I screwed it back in I snugged it tight and the switch turned in a bit, tightening up in the pan. It solved it, no more flickering or constantly on in 5th gear.

So, I ended up messing around with the bike's wiring quite a bit today to solve another problem: repetitive fuse blowing.

In doing so, the Neutral light problem seems to have been remedied. At least for now.

I did tighten that screw on the bottom of the engine, but I did not take it out and clean the parts as 750K did. So that might have been what did it.

Thanks to everyone for their input.

[bollingball]

Also worth noting, maybe, that My clutch perch broke, so I bought an after market perch and just shorted out the circuit that keeps the bike from starting unless the clutch is pulled.

That is the reason the neutral light is flickering. The switch on the clutch perch and the neutral light share a common wire. That light green wire.
Look at the wiring diagram in the Clymer's manual and you will see how they are interconnected. Fix the clutch perch and that wire for that switch and the neutral light should stop flickering.

No need to mess with the neutral light actuator on the bottom of the engine.
Just a chance to get an oil leak by messing with it.

I don't think so lucky he tied it back together in the bucket. It was probably the lose screw on the  neu. sw.
 Mingo I would still take the screw out spray it with some degreaser blow it off good and put a 1/2 drop of blue lock tote on it.

Ken

[scottly]

If the wire at the switch was loose, or the switch retaining bolt was loose, the neutral light might not light up while in neutral, or be intermittent, but it would certainly not cause the light to come on when in gear.
Edit, now that I think about it, if the retaining bolt was loose, and the switch was not fully seated, that could allow the light to come on.

[Mingo]

The K8 carbs have the drain screws instead of the drain plugs. The fuel level inside the float bowls can be checked with the clear tube method, by replacing the hoses at the bottom of the float bowls with clear plastic tubing and loosening the drain screw. I would check that before removing the float bowls.

Okay, now I'm back to this problem--the bogging at 5500 rpm. I put a wet rag against all headers and all are apparently equally hot. If I put transparent tubes on the bottom of the carbs and then turn those screws, what will I be looking for? That fuel comes out of all of them? Anything more subtle?

[scottly]

You hold the clear tubes up vertically, next to the float bowls. The fuel inside the tube should come up to about 3 mm below the top of the bowl, where it meets the carburetor body.