Yamaha TRX850 Enthusiasts Forum

I've been lurking for a while stealing advice from the many experts here, and I've encountered a problem that I can't find a direct answer for. So I thought I'd say hello, and hopefully get schooled as well.
Basically, after sitting for a month or two, my beloved won't start. Worked from the fuel tank forward and discovered I have no spark to either cylinder. I'm assuming both coils failing at once is unlikely so possibly its the CDI.
Now the question. Is the CDI specific to the TRX or would one to fit a TDM be acceptable? I've found a cheapish TDM one but the manufacturers code (4TX-82306-00) is not the same as mine (4UN-82305-00). I realise this may be a foolish question but I'm only a bodger. I'll go buy a full price unit if I have to, but I'm also trying to fix up a Moto-Guzzi Nevada for touring atm (my last 500 mile round trip on the TRX was... unpleasant.)

Anyway, thats not much of an introduction. I'm Brains, I'm from (almost) Belfast, and I fell in love with the TRX when some fella hoooned it past me on the motorway one evening when I was pottering on my Fazer. The only other one I've ever seen in Northern Ireland was in the local gumtree a few years later, and I bought it.

Cheers.
Brains.

I think the TDM has a different firing order mate, no luck there

Find someone near to you and ask to borrow the ECU
Being sure before you buy

Before you go replacing the CDI etc, check the starter relay! The bike will still turn over but there will be no spark, check that you have power to the CDI (red wire at CDI, check with ignition on).

These relays will fail due to the rise and fall of the ocean, when sparrows start to breed and when you forget to wash you hands….

If it's dodgy then you will get no spark etc, it also powers the side stand switch and the clutch switch and if any of these are not working as they should, then no spark. If the bike has been sitting then there could be corrosion on the connectors etc.

It's the double relay mounted in front of the battery.

You are on the ball Rod.

Yep follow Rod`s `lead` first. Hello and welcome too.

Guys, thanks for the help. After ages of general knobbing about and a few failed hardware swaps (thankfully not too expensive and resaleable on ebay) I took the plunge and went at the electrics with a multimeter and a manual. As of 20:30 tonight, the beast lives again!
Ohmage (?) was off on the leads to the alternator so swapped out the stator and pickup for one I got for £20.
Cheers again, hopefuly this post may point others in the right general direction for similar problems.