The consumption of two bottles of wine will have nothing to do with your divergence from the topic in hand, of course!

Diode or no diode it's not likely to have started backwards... but not impossible. I've only seen it happen (unintentionally) a couple of times... If engine barely catches... like almost doesn't start... might "cough" or "pop" right as it starts... Sounds strange... sort of "flat" because timing is way retarded...

Funny time was buddy at bottom of driveway revving his little 80 and going to "pop a wheelie" to show off... we almost died laughing when bike shot backwards when he dumped the clutch and fell over the handlebars.

I've been swapping out carbs till I found one that worked, rejigging the electrics, running out of fuel on the test bottle it's running from... it's had plenty of moments of not starting well or running rough but with so many variables I'd not really paid attention! If the timing was well out I'd not be surprised!

I could imagine this scenario:

First start - tachometer not working (actually just jammed and needs a bit of a whizz from the drill)
Second start - bad kick where engine just catches gets it going backwards (bike static and never put in gear at this point)
Third start - I give up on the tachometer and go for a ride (engine now warm and starts easier)

Certainly more believable than me somehow cocking up the tacho gears in the crank case Shame I have to work tonight otherwise I'd be on it straight away. I'm minded of that old Chinese curse: "may you live in interesting times"

Actually is that the answer [cocking up the tacho gear]. Can it be flipped over end for end & still engage on the crank gear plus the cable gear without something getting in the way??--is this the answer to the impossible or improbable question. There gotta be a first for everything.
www.partzilla.com/catalog/yamaha/motorcy...175b/tachometer-gear

That would be a convenient answer but no, both parts 3 and 5 only fit one way round for the tacho cable to spin at all.

I think on a worm gear you'd have to physically move the driven cable gear to the other side of the plastic drive gear to reverse the rotation... which would require a new side cover casting with the tach drive moved... or maybe get a set of gears with the opposite cut.... I just don't see any way direction could be reversed accidentally.

The plot thickens: although cold and damp out tonight I have braved the elements just for you guys

I sloooooowly depressed the kicker and.... the cable still rotates counter-clockwise :( F**k it, I may as well buy an angle-drive.

I really can't believe the Euro 1G1 model rotates in a different direction to all the other DTs!!! Definitely popping the crank case cover this weekend.

OK, This mystery keeps on keepin on....you got my attention...I can't wait for the solution. Should be good...

Umm mm nothing--run outa ideas. Ok i'll drag out my AT1 today just for a look to compare. Tachs & speedos are magnetically driver [are they not].

I just had a feeling before I even replied to the original question that this was going to go like this.

I just don't believe that Yamaha would decide to reverse the tach drive on one model... when every Yamaha enduro tach I've ever seen is pretty much interchangeable. And yes, RT325, the gauges are mag drive of some sort so if the cable on a 1G1 rotates opposite, then the tach needle would need to sweep from right to left (counterclockwise) instead of left to right (clockwise)... anybody ever see counterclockwise tach on a Yamaha enduro from the 1970's or 80's? One where the needle sweeps backwards? Maybe on some obscure model but not common to see counterclockwise sweep gauges on anything.

If it's not what I suggested at first... confusion on rotation direction... semantics... something like that... which is easy to do and understandable... I just don't know what it could be?

(If going into the cover "fixes" it... I'm not buying it without photo proof of what was wrong. I've worked on too many of these and happen to have a cover on the bench with that era tach drive and there is just no way to put it together wrong.)

Anyway, in the interest of clarification, here is a photo of a tach cable showing the direction the inner cable spins looking at it from the top.





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