Cable driven tacho revisited.....

[Linegeist]

There's just something about a mechanical rev counter that appeals to me ...... as long as the camshaft's turning, then it'll show pretty much exactly what speed the crankshaft's turning at (x2, natch'). I don't trust these electronic gizmos with LED displays and invisible electrons whizzing about all over the place. An proper honest tacho's got grease in its cable and makes a whirring noise when working, just like the God intended! Anyway, as my original Skorpion tach's totally stuffed (aren't they all? ) I want to replace it with a proper non-techie tacho.

So, I've now got a very nice, clean, cable-driven Suzuki clock - with cable - and all I need to do is connect it to the Skorp's camshaft.

Now there's a blanking plug with an 'O' ring fitted to the right hand side of the Skorp's cylinder head, in the middle, that reveals the end of the hollow camshaft. This has a cross-pin that fits into the little drive gearbox (arrowed in the drawing below) which transfers the drive through 90 degrees and into the cable (otherwise you'd have a foot or so of bendy tacho cable waving in the breeze, see?).

The question is, does anybody know what other engines use this tacho gearbox, please? The dealer wants £70+ VAT + carriage for a new one ............ that's more than I paid for the replacement tacho AND the cable............

I've bunged the drawing up so you can see what I'm burbling about.

SRX600 Cylinder Head.jpg (19.81 KiB) Viewed 2830 times

[Bill Jurgenson]

XT550, TT600, XT600/Z/E/K, XTZ660 srx use this bevel drive. The price of £70 is less than the standard one to be expected when new.
You can get it from KEDO:
you can change the language to English

Assuming the frame doesn't expire:
that's on page 79 of their catalogue:

27296 Getriebe-Einheit Drehzahlmesseranschluss
XT550, TT600, XT600/Z/E/K, XTZ660
Manufacturer: Yamaha
XT600 Drehzahlmesser-Antrieb
Zum Nachrüsten von XT600 und TT600 geeignet
Einfacher Selbsteinbau, Motor muss nicht geöffnet werden
Original YAMAHA Ersatzteil, Lieferung inklusive O-Ring sowie Simmerring komplett (Instrument und Drehzahlmesserwelle bitte separat bestellen), Farbe silber
Order this item:

27296 Getriebe-Einheit Drehzahlmesseranschluss
XT550, TT600, XT600/Z/E/K, XTZ660

Status Price Add Quantity
Special order, no stock 105.00 €
Price includes VAT and excludes shipping cost

105€ = £82,70 plus shipping

otherwise, you'll just have to watch eBay until something comes up.
I used a mechanical tach on my racer as long as the magneto was in use because the mag would not drive an electronic tach. Works of course. but cheaper it definitely is not.
A Scitsu is cheaper and much better. The third from the top, code red.

[Linegeist]

Thanks Bill <Gulp!> that's a lot of beer tokens for an impoverished techie like me ..........

The model info was what I wanted - again I owe you a bier .............. when I'm next in Germany, usw...usw ....

Thanks!!!!!

[hutchy]

Who needs a tacho on a big single just rev it tll your fillings start to rattle with the vibes then change gear

[Linegeist]

When you get to my age Hutchy, that's about 3000rpm.

Actually, I want a rev counter because it's a bloody long time since I rode a big single - the last one was a 500cc Arial. Now the Yamaha 660cc engine isn't a low-revving slogger like the Ariel, and to treat it like one would wreck the bottom end. The big problem is that all my instincts want to leep the revs low and the torque high ........... not good for a modern motor.

Basically, I'm having to re-learn how to ride a big single, and how to calculate what a modern engine's doing through the seat of my pants. The only way to find out what revs it's ACTUALLY doing and not what I think it's doing .......... (which usually sounds like bursting point to my 'Brit-single' ears and about to chuck a rod ) is with ..... yup. A tacho!

See?