Why does my bike go better on 98?

[Laava]

Yup, I do it by measuring the clench marks on the passenger seat after ridin 2 up

Forgive me I didn't realise you were in fact an instrumentation boffin!

[ellipsis]

...after pushing a mates bike for what seemed many leagues, once, and cursing all things fuel related, I discovered that it ran a lot better if the HT lead was connected to the plug...

[pritch]

From the dusty cobwebbed archives of my brain I seem to recall reading that the "seat of the pants" measuring equipment can't detect an improvement (or decline?) in performance of less than 10%.
Hard to imagine an improvement like that from a few extra octane. On the other hand if you like it and no kittens are harmed in the process, go for it.

[ellipsis]

. On the other hand if you like it and no kittens are harmed in the process, go for it.

...or dogs...

[AllanB]

...or dogs...

Dogs are expendable in the pursuit for more power.

[caspernz]

Dogs are expendable in the pursuit for more power.

But only if ACC isn't funding the "research" along the way

[lb99]

From the dusty cobwebbed archives of my brain I seem to recall reading that the "seat of the pants" measuring equipment can't detect an improvement (or decline?) in performance of less than 10%.
Hard to imagine an improvement like that from a few extra octane. On the other hand if you like it and no kittens are harmed in the process, go for it.

Was running 91 when I joined the dead cat gang 😦

Burned up a bit of fuel today, highway and town, and have come to the conclusion that the bike runs smoothest at over 3000rpm, anything below that is rough and annoying, so I will use that as a benchmark, try a few different fuels and see which one makes the most difference at 50k in top (2krpm)
I doubt there is any horsepower difference, but smoother and less buzzy around town would be great

[RDJ]

I like the Placebo Effect of filling the V8 bikes and the blown ute with 98. That's enuff reason for me. Anyway I'd only waste any money saved on rates and GST on home improvements otherwise

[neels]

As previously suggested, may be more to do with the setup of the bike being more suited to one octane rating than the other, just because it states that you can run on it doesn't mean it's running at its best.

All of my current fleet specify 95+ so don't get to experiment any more, my last car that wasn't fussy I ran on 95/98 because it actually cost less to run than on 91 when you worked out the mpg over a decent period of time.

[madandy]

perhaps the base ignition timing has been advanced from stock...a few degrees makes a noticeable difference

[Crasherfromwayback]

83 GPz1100 Unitrack, fuelled up with bp98 as an experiment, I was avey surprised to notice a significant difference in smoothness and response, I am very impressed. But I am confused. The motor is hardly specced to run such a high octane, 2v fuel injected air cooled 8.7-1 compression, so hardly a high state of tune, but the difference between 91 and 98 is instantly obvious. Why?

Is it a nice one? If so, be sure to let me know if you ever want to sell it.

[Crasherfromwayback]

. but how long will the motor last with those bigger bangs ... ???

Won't be breaking one of those engines anytime soon. Mine was taken to 1175 with much higher comp and got the shit beaten out of it for years. No problemo.

[lb99]

Is it a nice one? If so, be sure to let me know if you ever want to sell it.

https://www.kiwibiker.co.nz/forums/s...post1131027269

Theres a pic in this thread as it was when i got it, i have since repainted all of the red, new screen and seat, and new decals, looks a heap better. Will do the black parts next winter

[lb99]

Won't be breaking one of those engines anytime soon. Mine was taken to 1175 with much higher comp and got the shit beaten out of it for years. No problemo.

Was it really buzzy?

[Crasherfromwayback]

Was it really buzzy?

Yeah they do tingle a fair bit. Nothing more than a typical big four though. Make sure the engine mounts are tight.