Troubleshooting starter circuit..

Hi all

Hope someone can help. I have a UK spec 550 (seca) newly fitted with a radian (YX600) engine and TCI.
From what I gather (and remember from past ownership 30 yrs ago) there is no side-stand switch/relay for this model
but there is a clutch switch (although not yet on my bike).

Looking at the US wiring diagrams (no Uk one seems to exist) It looks like the cut off relay is 'fed' by the neutral
switch and the clutch switch which must both be closed (to ground)- correct ? The sidestand switch/relay must connect to the TCI but if no switch relay (as in my case) the terminal should also be shorted to ground.

Presumably if the circuits are all good to the cut-off relay and the starter relay is good/working then the starter motor will be energised. The TCI however will not fire unless teh side-stand line is grounded .

Does this sound about right or did I miss something ?

Cheers

James

 

Starter circuit cutoff relay is typically an "or". Either the bike has to be in neutral or the clutch pulled in to engage the starter cutoff relay. On a similar US model with no side stand relay, one end of the starter cutoff relay wires directly to the clutch switch. That same end also ties to the neutral switch, but is routed through a steering diode (diode block).

On the US models the side stand relay has a set of normally closed contacts shorting the TCI pin to ground, usually a blue/white or black/white wire. In a safe condition, the side stand relay contacts open and lift the pin off of ground. If there is no side stand relay, then there is not a contact to disable the TCI and likely not a wire connected to tie the pin to ground to disable it.

 

Kinda. On US models if the sidestand is down the bike won't start in gear even if you pull the clutch in. (This applies to sidestand-switch equipped bikes.) Pull in the clutch and drop it in gear with the stand down and it will shut off. With the stand up the clutch switch will override the safety circuit; but the sidestand takes precedence.

 

Rooster, BF

Thanks - that helps a lot. I hadn't figured the OR function, was still on the AND route - diodes eh ?

One final ( I hope) Q. Will the motor spin, but not start, with the sidestand down (B/W wire to TCI disconnected) if teh other two conditions are met ?

Cheers

James

 

If you don't have a side stand switch, then there is no circuit monitoring its position so up or down is irrelevant.

Don’t think there is a designed condition where the motor will spin and not start unless there is a partially defective safety circuit disabling the TCI and resulting in no spark. I believe this would apply only to side stand equipped bikes.

The enable / disable pin on the TCI (blue/white or black/white wire) has to be pulled to ground to disable the TCI, which means the bike must have a side stand relay to accomplish this, or someone has tied the wire directly to ground.

Are you chasing a no spark condition?

 

Thanks - I assumed the other way around i.e Grounding TCI sidestand input would Enable the ignition box - so in fact I can leave it open ?

Not at the 'chasing no spark condition' yet - still chasing the no turny-over part - so a long way to go. This bike was in a pile of boxes for 15 years before I got it last year. On the plus side I have got a neutral light, brake light , and headlight now.
I may end up bypassing the cut-out relay at least temporarily by joining the two red/white wires. Starter motor is good since I can power it directly - just wanted to get if off from the button.

 

Update - cut-off relay is reprieved after I found 12V on the red/white wire at the solenoid. Traced problem back to filthy dirty starter button which I thought I had cleaned - apparently not !

BTW 1 - The oil light comes on with the starter/solenoid - this correct ?

BTW 2 - I couldn't find the diode pack in the headlight shell and thought that on Euro models it was under the tank - I fact I think I was looking at the indicator canceler . I checked out the spare loom/frame I acquired from 'Greg in London' and there was what looks like a diode pack in the shell but it only has three wires ! Seems there are quite a few differences in the Euro wiring but no diagram to be had anywhere !