Thinking caps on....

Pop quiz everyone:

98 TDM 850.

Started & ran fine this morning.

Leaving work just now it wouldn't start. Eventually started. Ran fine 15 minutes, stopped for fuel and now won't start again.

Battery is fine. Starter spins plenty fast. Sometimes it coughs like it's gonna fire (no throttle). As soon as I give it any throttle it just turns over again. Was the same with choke. HT's seem connected ok - no tools so can't check for spark.

Anyy ideas ???

Pull ignition lead, buy a twix, roll foil up push in lead put next to engine see if it sparks, be dark soon easier to see spark.

After cranking sniff the exhaust to see if there's a smell of unburnt petrol.

Did you use choke to start it after work?

Try it with no choke and the throttle fully open.

Pull ignition lead, buy a twix, roll foil up push in lead put next to engine see if it sparks, be dark soon easier to see spark.

There are other chocolate Bars available

Thanks guys.

Got it going again.

And I think I've sussed the problem....

The switch in the ignition barrel may be worn out.

When it turns over and over without firing if I take the key out, put it back in and then try again it'll fire as per normal.

Recently (the last week or so) the ignition barrel feels a bit notchy, like something's a bit loose inside and catching as the key turns.

Or possibly it's been got at, cos I had trouble undoing the chain locks too about a week ago, like something had been shoved in the locks to force the tumblers.

Interesting idea with the twix wrapper though would a KitKat be better, being foil as opposed to plastic??

Incidentally, I've never needed choke to start it - in fact I'm pretty sure the choke doesn't work (common TDM issue) or is permanently part open - it runs a bit rich.

Glad it's going and you've got an idea what it might be.

Just wondering....does it have an immobilizer? Some prevent cranking but others disable the fuel and/or ignition. If the switch has been damaged could it be intermittent immobilizer failure?

Incidentally, I've never needed choke to start it - in fact I'm pretty sure the choke doesn't work (common TDM issue) or is permanently part open - it runs a bit rich.

Emulsion choobs.

Anyway, when it won't start do you get one spark and then nowt? Because that'll be the little wires to the ignition switch not being connected together by the switch, it's some weird anti-theft thing that Yamaha were doing at the time. At least that's how the TRX is wired up and I'd guess the TDM is the same.

Pull ignition lead, buy a twix, roll foil up push in lead put next to engine see if it sparks, be dark soon easier to see spark.

Twix ? Surely you're thinking of a Kit Kat but they don't come wrapped in foil anymore .

Glad it's going and you've got an idea what it might be.

Just wondering....does it have an immobilizer? Some prevent cranking but others disable the fuel and/or ignition. If the switch has been damaged could it be intermittent immobilizer failure?

I don't think it has an immobiliser.

But I will find out when it comes off the road for winter.

Pull ignition lead, buy a twix, roll foil up push in lead put next to engine see if it sparks, be dark soon easier to see spark.

 

Twix ? Surely you're thinking of a Kit Kat but they don't come wrapped in foil anymore .

Hangs head 8n shame, you are correct

Actually is anything foil wrapped any more.

Incidentally, I've never needed choke to start it - in fact I'm pretty sure the choke doesn't work (common TDM issue) or is permanently part open - it runs a bit rich.

Emulsion choobs.

Anyway, when it won't start do you get one spark and then nowt? Because that'll be the little wires to the ignition switch not being connected together by the switch, it's some weird anti-theft thing that Yamaha were doing at the time. At least that's how the TRX is wired up and I'd guess the TDM is the same.

That sounds likely - I can't imagine the ignition being any different on a TDM to a TRX. I'll try to check that out in daylight.

Yep, carbs are first on the list for refurb over winter.

Pull ignition lead, buy a twix, roll foil up push in lead put next to engine see if it sparks, be dark soon easier to see spark.

 

Twix ? Surely you're thinking of a Kit Kat but they don't come wrapped in foil anymore .

 

Hangs head 8n shame, you are correct

Actually is anything foil wrapped any more.

I think some of the more expensive chocolate bars such as Green and Blacks and Lindt might possibly have foil as inner packaging .

Caramac ... no foil , just eat it .

Caramac , won’t help you , just eat it , hmm

Pull ignition lead, buy a twix, roll foil up push in lead put next to engine see if it sparks, be dark soon easier to see spark.

 

Twix ? Surely you're thinking of a Kit Kat but they don't come wrapped in foil anymore .

Twix ? Surely you're thinking of a Kit Kat but they don't come wrapped in foil anymore .

Wrong! Although you have to buy the two finger multi pack to get the foil wrapping.

So really it's win-win!

Twix ? Surely you're thinking of a Kit Kat but they don't come wrapped in foil anymore .

 

Wrong! Although you have to buy the two finger multi pack to get the foil wrapping.

So really it's win-win!

I did suspect that the two finger still had foil .

I did suspect that the two finger still had foil .

Lucky for you I put the leg work for you then Bob.

All part of the service.

Hi

If the switch turns out to be goosed have a careful look at how many keys etc are on your keyring.

I have seen a lot of bike and car ignition switches wrecked by keyrings with spare keys house keys and all sorts of other crap bouncing about!

If you need to replace switch please check out Wemoto before visiting a main stealer !

Cheers

Ian

Hi

If the switch turns out to be goosed have a careful look at how many keys etc are on your keyring.

I have seen a lot of bike and car ignition switches wrecked by keyrings with spare keys house keys and all sorts of other crap bouncing about!

If you need to replace switch please check out Wemoto before visiting a main stealer !

Cheers

Ian

Useful info, thanks