Back when Yamaha almost went crazy

[RhynoCZ]

Link: https://www.thedrivershub.com/back-when-yamaha-almost-went-crazy/

https://www.thedrivershub.com/wp-content/uploads/2024/05/241438502_10166432625280112_1601983415064412434_n.jpg
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'87 Honda XBR 500, '96 Kawasaki ZX7R P1, '90 Honda CB-1, '88 Kawasaki GPz550, MZ 150 ETZ
'95 Mercedes-Benz w202 C200 CGI, '98 Mercedes-Benz w210 E200 Kompressor

[Nobby the Bastard]

They didn''t go crazy, they settled on a 5 valve per cylinder head But found a 7 valve 2 spark set up was slightly better.

Thats F1 for you, the best of the best but the margins and reliabilty were too small for the return so settled with the 5 valves. My FZR and FZ had a 5 valve head...
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[A100man]

[Nobby the Bastard]

You have to remember back then Yamaha were in F1 with V10 and V12 engines.

If us laymen can do 5 valve per cylinder then F1 mechanics can and would do 7 valve.

These days it's all done in the factory, I did the shims for my FZ on my driveway....
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[stinkwheel]

Despite only having a relatively mundane 4 valves per cylinder. I still think the RC166 takes the biscuit. Given it's 250cc and is revving out at 22,000rpm... And they're desmo.

https://res.cloudinary.com/tbmg/c_scale,w_400,f_auto,q_auto/v1705808851/sites/ae/articles/2023/features/SAE-MA-07146-honda-gp-rc165-cylinder-head-gallery-a.jpg
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Nobby the Bastard]

The thought of that has me gibbering in a corner.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[A100man]

[stinkwheel]