Anyone Racing/restoring an F9 350 Big Horn

[265coupe]

Hi,
I have a couple of NOS cast pistons that I believe are from a Big Horn.

If they are of any use to anyone could we talk. I can measure them and compare them with what was original. If they are correct then they're yours for $20ea plus postage.

They're bare with no rings or pins.

Thanks
Mick

[Lozza]

Thread dredge alert.
Just picked up a Big Horn engine anybody got any specs? Bore stroke rod length internal gear ratios etc etc

[DR]

Loz..

gear ratio's
1st 2.45
2nd 1.71
3rd 1.17
4th 0.90
5th 0.71

primary reduction ratio
3.04 (73/24)
final reduction ratio
2.93 (41/14)
overall drive ratio
6.32

Bore 80.5mm
Stroke 60.8mm
ign timing
3.41mm btdc 23°@6000rpm

I have Manuel here beside me

[Lozza]

 Que !   anything unusual or interesting in there?
can you tell if the gudgeon is 18 or 20mm, rod length?
are the individual gear ratios listed?
Gracias

[DR]

Loz, will get together what I have but I only have F5 information. The F9 would close to the last of the F5's I guess but there was a ratio change during the F5 production run so this may offer up some alternative ratios. I do have the teeth count also but they're in separate books so gimme some time to collate it. Sorry for the hijack 265 but it does keep your post at the top of the list  

[Lozza]

No worries Doc speaking of pistons 3 rings WTF
EBAY LINK

[DR]

  yeah, 3 rings on F5 and F9 slugs, s'pose they figured since it had a valve it should have an oil control ring as well but other than that I can see no reasoning excepting maybe someone stuffed up at the piston factory

[211kawasaki]

Why Why Why

[buckets]

I remember riding one of these things that got stuck on full throttle in the bush... its as clear as if it was yesterday.. we also had an RM250 B in the crowd. but compared to the Big Horn on full stick the suzuki was a piece of cake....