I don't know if this applies to all premium fuels, but it's worth a read, as it will increase your knowledge -- <!-- m --><a class="postlink" href="http://www.shell.com.au/oneshell/au/optimax/pdfs/optimax_motorcycle.pdf">http://www.shell.com.au/oneshell/au/opt ... rcycle.pdf</a><!-- m -->
some interesting stuff there - didn't know it was denser than normal fuel - and having to change the jetting to suit...
I was a bit suprised myself when that was mentioned. There may be some benefit running that in a modern car without retuning. My bike is fuel injected but does not have an O2 sensor (like most FI bikes) so it won't compensate, but it can be easily remapped.
No wonder my FZR started stalling/boging down when I changed over to PULP. Now back on ULP and the problem has gone.
i found i got about 20ks more out of a tank when puttin vortex in my bike but besides that no benifits... but then that might not be a benifit because the high <!-- s:$: --><img src="{SMILIES_PATH}/th_dollarsign.gif" alt=":$:" title="Dollar Sign" /><!-- s:$: -->
I had to drain a full tank of that **** on sunday.Put ULP and now she goes like a dog shot in the ass.
ok so i did alittle test after reading this i thort id see what happens when you run a couple of tanks of PULP so it felt the same till you try and open it up (i just changed to a 15 tooth sprocet on the front so not to shore whats the sprocet and whats the PULP) -it doesnt have that same kick at 12 000 rpm -it brogs down around 14 000rpm -and it brogs down when you change gear (using clutch) does this sound like whats happening to everyone else?
I have noticed mine boging down alot, and I run every second tank premium... I think I shall go back to the cheap stuff
I noticed the flat spots in my power curve a lot more when i changed my sprokects - mainly because there's not much difference between a little bit of acceleration and a little bit less Put a smaller front sprocket on and the difference is greater, making it much easier to notice.
The FZR would most likely have been designed to be run on ULP. The boging down everyone is getting is the air/fuel mixture being too rich. As shell say some older bikes with carbs need to be be rejetted.
Definitely. The truth is these bikes were designed from new to run on the slightly higher grade fuel that is available in Japan (ie. ~95RON). Over time with the wear and tear on the carb needles & emulsion tubes the majority of bikes this era are now running rich meaning that running on a less dense fuel helps the problem slightly. My advice for anyone experimenting with fuel would be to run plain old boring ULP unless you've had your carbs completely rebuilt (new needles & tubes) in which case i'd recommend running 95RON or higher.
I just had a thought ( shock horror <!-- s:shocked: --><img src="{SMILIES_PATH}/th_shocked.gif" alt=":shocked:" title="shocked" /><!-- s:shocked: --> ) - Has anyone who has had problems with running rich, fouling plugs, tried using E10 fuel (contains 10% ethanol) ??? Because it needs to run at a slightly lower air/fuel ratio, it may be of some benefit to people with worn carbs... It also has a higher octane rating than unleaded too.
