YT6700 no spark

[Meofouse]

Been several years since I posted here, last time was when I rebuilt the hydro.
I was cutting along and suddenly it seemed like the tractor jammed up, bogged down and quit running. I managed to restart it but smoke billowed out from underneath. Now it turns over, sounds ok but there is no spark. Any suggestions before I pull the top and check the coils? It has run like a champ for the past several years with no problems.
Cal

[spider79]

Change spark plugs if blue smoke blowing out they could be gummed up

[Meofouse]

Naw, plugs are clean, it smoked from the engine itself. I'm going to pull the flywheel this weekend. The way it shut down was like something jammed to hold it from spinning. I'm thinking maybe a part broke loose "upstairs" somewhere. Blades turn freely, PTO is disengaged. I'll do a compression check first to make sure nothing else is broke.
Thanks for the suggestion though.

[rattosh51]

no spark from both sides?
The dreaded coils are No longer available, last I heard, but someone had found a replacement.
Check the older posts. Let us know what you find.

[nascarjay]

I have a YT6800 that ran perfect, I than washed it and it has never started since than (2 years ago) I also have no spark and had it checked by a Yamaha dealer that said it was the rotor, that the magnet was weak and not producing energy to the TCI units to produce sparks to the plugs, I find that hard to believe cuz I tested the magnet and compared it the another YT6800 that I have and they seemed to be more powerful than the one that runs, anyways Im thinking in my case that its the TCI units cuz they said they checked the two coils and were good. Anyways I have been able to find coils, but not the TCI units, but Im wondering if by chance another TCI from another Yamaha product might work, any Ideas on that? if you need a coil They can be found from people on here that still sell new parts for them, Im thinking one place was called Yamaha motor sports or Genuine Yamaha parts something like that. Oh by the way there no rotors out there for the YT6800, the one I found was 300.00 and it was the wrong one and had to return it. Magnet was in the wrong location. So I bought another YT6800 that I entended to use for that part but Im afraid of taking it apart and end up with two that do not run, that be just my luck, the one runs pretty good and cuts OK but boy, my other one was/is so much nicer, so maybe try the swap next year.

[rattosh51]

Parts...

http://www.yamahagenuineparts.com
http://www.canns-bilco.com
http://www.powersportspro.com/pages/parts/viewbybrand/2/Yamaha.aspx


I've heard a lot of parts are common with the Yamaha motorbikes...

Jay--the coils I refer to are the TCI units...the TCI picks up the magnet going by creating the electrical
energy that goes down to the spark plug...and yes they are obsolete. Best bet is to try and cross match
with another Yamaha product like dirt bike or atv.