Modern Vespa

Hello All,

Has anyone replaced the Clutch indication switch on a modern PX150 without disassembling the entire handle bars? I have a PX150 that doesn't reliably start with the electric starter. The Relay tests good when bench tested and it appears that the switched ground connection of the neutral switch in the handlebars is faulty. I don't want to disassemble the entire left handle bar to replace it there is an easy way to remove the nut and fish another one in.

Any help or experience in this area appreciated before I remove the entire left handlebar and have to adjust clutch, shifting, etc.

SanJoe

This may not be received very well by purists and safety advocates.

I dislike clutch permissive switches on all types of manual shift vehicles. I disable them. It's a personal choice. I might be less apt to disable it when you have a back-up kick start.

If this is your wiring set-up, you could ground the pink wire from the start relay by the battery, and it should start without having to use the clutch. By using a jumper with the proper connectors, you can do it without cutting or splicing wires. Or do it until you have it apart for some other reason and then fix it.

It appears the starter protection relay is there to prevent you from grinding on the starter while the engine is running. Note to self: Don't try to start an engine that's already running.

Ground the pink wire at the starter protection relay under the horncast, and you will still have that safety. Stuff's gotta come off any way you do it.

http://www.allstyles-scooters.com/EStart_Circ.htm

Thanks B! I have the thing half apart now. I will check the relay under the horncast. That may be the problem. Haven't checked it yet. Was thinking its the switch. I already have the top and speedo off. That isn't that hard to do... The Speedo wasn't working so need to check the cable anyway.

Good point about grounding with a jumper. That should be easy to do.

jt

fwiw, I think it's there to prevent you starting the bike while it's in gear and having it shoot away from you down the road...

When you're kickstarting you're more likely to notice it's in gear before it gets very far. Hopefully.

As noted on the electrical diagram above, the later models have TWO permissives in the start circuit, in series. The clutch must be pulled in AND the engine must not be running. The clutch switch keeps the scooter from running away and falling down or worse.

The starter protection relay, the second, seem to be energized and its contacts open when the engine is running. That prevents you from engaging the starter while the engine is running and damaging the starter and bendix/flywheel teeth.

At least that appears to be what the drawing shows. I've never operated a late model PX.

you will not have to readjust your gear cables to get to the switch


the cluch cable inner must be removed= easy
and the wire for the swich can be jammed inside the gear shift tube
just take out the pin that holds the gear pull pull arrangement leaving cables resting in it then you can pull it clear

It looks like the switch is bolted into the handle... once you take the nut off, and I pull the cable out, is it easy to get the nut back on? I will test the relay under the horncast when I get the chance. hoping that is the problem..

just noticed you have a shitload of px's

yes i hope its a relay or check connections at the startor motor end,

since you have a few leccy start models you might as well swap a relay to test


ive never removed the actual switch on one ,, good luck with that

if it does turn out to be the switch i'd try blasting it with degreaser or similar,, might be just some crud in there,, since it is a very simple device


i think thats all i can say

Have just done this recently on an 85, px200e, mine was broken and had been earthed out. Horncast comes off and then the speedo top, release clutch cable and maybe lever out and old switch screws out used a 6 or 7mm t handle maybe join some thin cable or wire for the return trip down headset, hardest bit was routing the connector spade and wire back down to the relay, use a hook of wire to catch it in beside the head tube and pull out to connect.

Cheers Holger

ps anyone installed a front brake light switch, seems I need one for Roadworthy in Oz?

All modern models also. I love these things, they are like tanks. The thing that sucks about this failure, is that its a brand new PX150 2005 that was never started and came from a crate. I don't know if this was a problem caused by it sitting too long before being prep'ed but it has other issues... The Speedo didn't work either. Really bad quality coming straight from the factory. Good suggestion regarding the switch out of the relay. Its most likely there, or a faulty ground. I hit the neg and positive battery terminal by accident when I was removing the battery to check and it actually was able to start once.

yes,,,,, i had to slightly remove the headset to get the clutch switch wire back down


you can hook up a front brake cable switch to your back brake switch
my 85 bike doesnt have one but at some stage the wires where hitchiked there

any probs with the hitchike pm me when im sober

Thanks for the tip. I am glad I don't have to disassemble the entire handlebar.

Thanks to joshzingzing for asking status.. Problem is resolved. Turned out the switch was fine. For those who find this thread with a similar problem, I was able to un thread the switch and use conductive grease on the threads and reinstall. That did the trick. It was just a bad ground connection. No need to replace the entire switch.