Hello I have a question regarding the kill switch on my ty250 twinshock

I have been restoring the bike and purchased a "push to kill switch" as the bike never had one.

The swich that I have is a Normally open one, I would have thought that it would have been normally closed unless I am being thick. So the only way I can get the bike to run is to hold the switch in.

I have wired it so that one wire for the switch is coming from the points and the other cable is going to the coil I am hoping that this is correct and that I have just got wrong switch.

So my question is do I need a normally closed switch and is this something particular to Yamaha? as I cannot see how a normally open switch would work without a relay or as mentioned am I just being thick? If it is the wrong switch I will have to order a new one.

On a positive note the bike started first kick once I had by passed the switch, on a negative note I spilt some petrol onto the tank whilst filling it up and its had a good go at stripping the paint so I have got to paint the tank again.

I think I will have to put a coat of lacquer on it after spraying to try and protect the paint a bit.

Regards

Mark

No expert but just sounds like you have connected an earth wire instead of a power wire.

You take a feed from the coil wire (from the points to coil) to the switch and when you press the switch it should ground out the wire (earth the wire) to the handlebars and kill the engine

Dave

Just re-red your post and you dont cut the wire you add a wire on the connection so when you press the switch it earths out the wire

Dave

Thanks for the advice Dave.

I will put an Extra wire in later this week, You see I was being thick!

Regards

Mark

Mark,

There are (were) 3 wires coming from the stator onwards. The Black wire is the live wire and when I re-wire Yams, for competition use only, I put a splitter just before the top coil and and a single extra wire up to the kill switch. All single wire switches ground out through the frame/handlebars when the switch is depressed. You may find when you re-wire that the first 10 inches or so of the original wiring coming out of the flywheel case are brittle and if so should be replaced with new wires as this will save a lot of problems.

Tony

Thanks for the advice Tony, I have already replaced this wire when I rebuilt the engine because of the old one was brittle as anything.

Its a good idea to split it at the engine so I may look at doing that, Thanks for the advice

Regards

mark

Hope you have managed to fix it, just Incase you haven't I would like to point out the method you used would only work on a normally closed switch so when you push the button it breaks the circuit. As your switch is a normally open it is used to short out the coil to earth which is just another method of stopping it running, I think the problem that confuses some people is that some kill switches have one wire,which is the type that shorts out to the handle bar when pressed and the wire goes to primary side of the HT coil, or the type which you have with two wires, one wire goes to ground and the other goes to the primary side of the coil.

Thanks for the advice chaps, I managed to get out in the garage today for half a hour and run in a extra cable as suggested and it works perfectly.

As I had run my cables from the kill switch down to around the coil area I used one of the coil securing bolts for the earth. I have now Heat shrinked all my soldered connections in an attempt to weather proof them.

Again thanks for the advice, I now just need to find the air leak on the carb as the engine just seems to rev away, Hopefully I will be able to spend the whole day on tuesday doing the bike!! so that should nearly get it finished.

Regards

Mark

Get a can of wd40 or other type of spray and start engine then spray around the carb connection and reed cover and this will find the leak unless its a blocked air jet or seal

Dave