Gear Indicator Malfunction

[jkirk]

Hey Folks,

First, I would like to say hellow to everyone. Just about 3 weeks ago I sold my 2007 Yamaha FZ1 and picked up a 2008 FJR with 5900 miles on it. I have since run into one item that I'm trying to figure out. Every once in a while I will shift into 5th gear and the indicator on the LCD screen will go blank like I'm in neutral. The green light does not come on, but it does not show 5th. All other gears are fine on the indicator. Anyone run into something like this? I think the gear position sensor may be going bad, but I'm just guessing at that. I tend to think that I do not have a problem with the LCD screen...usually when those go they go completely and don't have intermittent come and go problems.

Thanks,

Jeff

 

[Constant Mesh]

When this happens you might pull in the clutch and lift up on the toe shifter again and see if the '5' appears. It gets its signal from the rotary position of the shift drum. The drum may rotate just a bit farther on the redo.

 

[jkirk]

When this happens you might pull in the clutch and lift up on the toe shifter again and see if the '5' appears. It gets its signal from the rotary position of the shift drum. The drum may rotate just a bit farther on the redo.

I've tried that, but it doesn't work. A couple of times it went blank and then 5 or 10 miles on down the road I notice that the 5 was indicated.

 

[dsmack]

I'd suggest that you disassemble the shift mechanism, clean all the pivot points and lube lightly. Sounds as though you may have some gunk in there somewhere that is causing the mechanism to bind slightly, causing the faulty (or lack of) gear indication.

Just a guess, but easy enough to try! B)

Don

 

[wfooshee]

The gear position sensor is a set of switches, one for each gear (duh!) that are grounded when that gear is selected. On clutch-lever bikes the neutral switch is part of the same assembly, but it's wire goes a different place once it reaches the main harness. If the display gets no ground from any switch, it leaves the gear indicator blank. The neutral light is lit by the neutral switch, though, so it won't light unless you're actually in neutral.

It's possible for an individual switch in that package to go bad, get grungy, whatever, but it's not exposed to weather. Of course they are not individual part numbers, it's the whole shebang is all you can buy.

That switch is on the left side of the bike, I think (since I've not been there on a gen-II) it's right above where the shifter goes into the tranny. It has an O-ring which probably should be replaced if it's removed.

 

[Constant Mesh]

It's really not much of a switch. On the left end of the shift drum is a spring-loaded pin which juts out to the left. The pin is one-half of the gear position switch. As the drum rotates from gear to gear the pin moves in a rotary circular pattern making contact with a series of separate little contact pads on the stationary switch assembly. The switch assembly is similar to the ignition switch up front with its stationary contact pads which are wiped by a moving contact.

Each of the six contact pads has a wire which connects to the display up front. When the spring-loaded pin touches a pad it electrically grounds the pad and completes the circuit. If no pad is grounded nothing appears on the screen. The 'neutral' pad controls the neutral light and associated circuits.

I don't believe there's an adjustment on the switch. Maybe there's an intermittent connection in the '5' wire. Or maybe the '5' pad is a little dirty and not making a good connection. You might remove the switch assembly and see if the pads are dirty and clean them as required. The two little bolts attaching the switch assembly are thread-locked with a recommended torque of only 3 ft-lbs. There's an O-ring around the switch body making it oil tight. When you remove the switch assembly the spring-loaded pin may fire out -- I've never removed one so I don't know exactly what would happen.