Fuel to use for cbr250rr?

[Marky]

Hi all,

I am plaining on buying a cbr 250rr and am just curious on what fuel to use.

A mate told me to use 98 and someone else said to use 105 octane racefuel, that one sounds a bit extreme but i dont no very much about the subject so any tips or feedback would be much appreciated.

[scooterboynz]

i personally use 96 , i have heard that race fuel can perish the rubber hoses on older bikes if left sitting for a while , how true his is i am not sure? if i was you i would use 96

[James Deuce]

It will be fine on 95.

Try all the normal pump gas until you find what works best for you. Run a tank through to reserve, and then fill up with the next type. "Race" fuel? 95 Octane unleaded in MotoGP.

[scooterboynz]

"Race" fuel? 95 Octane unleaded in MotoGP.

105 octane is sold out at puke and st hway 16 on the way into kumeu

[HDTboy]

I run mine happily on 91 all day every day

[James Deuce]

105 octane is sold out at puke and st hway 16 on the way into kumeu

Yes but my point is is that it is completely unecessary, and given that it burns really slowly, if you don't do a bunch of other changes like plugs, and maybe increasing the compression ratio, you may end up spending more money to make your bike go slower. Or even reduce it's maximum speed to the speed at whihc you can push it.

[bugjuice]

lol.. 105!?!? good luck finding that at your regular motion lotion station..
most of the older bikes were designed and built during the golden age where 91 was a premium buy.. so stick in it what you can find.. you might find 96/5 might give it a little more ummph, but doubtful. 91 will be fine..

Newer bikes benefit from higher rated fuel, but you don't have to worry about that just yet..

[SARGE]

CBR250's are not super high comp motors.. alll you do when you constantly run 96+ through her is waste $$..

run Gull 91 and once every 4 or 5 tanks, hit her with BP98 and give her a fang to de-carbon the valves

[The_Dover]

Use diesel bro, it will give you bags of torque and a nice V-Twin rumble.....

[FlyingDutchMan]

CBR250's are not super high comp motors.. alll you do when you constantly run 96+ through her is waste $$..

run Gull 91 and once every 4 or 5 tanks, hit her with BP98 and give her a fang to de-carbon the valves

You're much more likely to carbon them up with 98 than 91 simply because it runs too cold. You cannot get more power/efficency out of an engine by running a higher than required. All the CBR250 needs is 91, so you're wasting money by putting 96 or 98 or anything higher in.

[Magua]

I went from 91 to 96 in my fzr250. I didn't notice a difference.

[Paul in NZ]

I went from 91 to 96 in my fzr250. I didn't notice a difference.

What? Miles an hour?

[Magua]

What? Miles an hour?


88mph.....

[texmo]

I went from 91 to 96 in my fzr250. I didn't notice a difference.
I was gonna have a fizzer as a loaner bike from Mt. Eden but ended up giving me a ZXR250, I must say after riding that fzr not offence, but why the fuck would you buy one, ok its a little less money, but you get that money back..
I would far rather have an rg150 which is in the same price bracket... It was just shit brakes shit tyres shit frame shit handling not much power.... there was some strange clicking nosie coming from the motor that was "normal" I mean its already a peice of shit what is another design floor? if you own one, please flog it off to some poor punter, and get something else... Please

[myvice]

Ran 96/98 in my CBR, didn’t have any problems with it fowling up and I used to get about 200ks before hitting reserve.
Same as my Bandit...
108 is race gas and if you want to go faster then get a bigger bike!

[TwoSeven]

run it with 91 - its fine.

[FlyingDutchMan]

Mine does 280 before htting the bottom of the tank. Excpt when it decides to hydrolock & i'm forced to waste good petrol & drain good oil :mad: :mad: :mad: :mad: :mad: :mad: (Like today).

[TwoSeven]

shouldnt be hydro'ing. You running a cr9 in it or somthing.

[FlyingDutchMan]

Hydrolock has absolutely nothing todo with spark plugs. In my case the float valves stuck open and petrol filling the cylinder to the brim. Doesn't go anywhere & is a pain in the arse to rectify.

[marty]

Hydrolock has absolutely nothing todo with spark plugs. In my case the float valves stuck open and petrol filling the cylinder to the brim. Doesn't go anywhere & is a pain in the arse to rectify.

why dont you either turn off the fuel when it's parked, or putting a vacuum operated fuel switch on the line from the tank?

[TwoSeven]

Hydrolock has absolutely nothing todo with spark plugs. In my case the float valves stuck open and petrol filling the cylinder to the brim. Doesn't go anywhere & is a pain in the arse to rectify.

I didnt say it did. Just the two most common problems with kiwi motorcyclists are running the wrong fuel/plugs and not fixing their carb problems. If it wasnt one, it would be the other :)

[Cibby]

just fucken buy it

who gives a fuck..


:rockon: :rockon: :rockon: :rockon:

p.s you obvious have good taste ;):doobey:

[FlyingDutchMan]

why dont you either turn off the fuel when it's parked, or putting a vacuum operated fuel switch on the line from the tank?

All sounds simple, but I have a fuel pump which lets gravity feed petrol through slowly when off and a fuel tap with only 3 settings - on, on or on. One day I should get round to fixing it properly. Getting some POR-15 tomorrow to clean out the tank to stop all the rust crap from keeping the float valves blocked open.

[TwoSeven]

lemmie know how that stuff works. I have to do the krappisaki and tha bantam at some stage.

[Coyote]

Could you get away with running a CBR or an RG on this stuff?
http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNE25&P=7

[transformerboy]

i like 2 use vodka! makes a nice change 2 petrol aye? have some urself!

[Coyote]

i like 2 use vodka! makes a nice change 2 petrol aye? have some urself!
I'd rather quench my thirst with gasoline :headbang:

[Sniper]

I could be wrong, but in a 250, you don't need to fuss too much over what petrol you use. My regime is 2 tanks of 91 for every 1 tank of 98, and I never run my tank dry.

[GNR]

I think my fuel tap has the 2 on on on settings, must be something in the mc19s,
I run 91, never have a problem, i get 200km, and thats 9L to fill her up, so prob about 288km per tank

isnt "race gas" expired aviation gas, so it 100LL ?? spose it depends on what "race gas" you buy/use

[justsomeguy]

just fucken buy it

who gives a fuck..
]

That's $80(parts) plus another $60 (labour) for a set of fouled plugs.

Use 91.

[FlyingDutchMan]

lemmie know how that stuff works. I have to do the krappisaki and tha bantam at some stage.

Welll I'm 1/2 way through doing it. It works well, but there is no where near enough 'metal ready' stuff in the kit. I went down to bunnings and bought 2 litres of Hydrochloric acid (spirits of salt) ~$20, and threw that in with 2l of water. Does a brilliant job - got about 1/2 a cup of rust out (just rust - not liquid!) :blink: Should have done that just before doing the metal ready. My metal ready was already all 'used up' (i.e. I still had liquid, but it did nothing) when I tried it after the HCl. My suggestion would be do the HCl then the metal ready. Since the metal ready was spent, I had nothing to stop the inside of the tank from rusting to hell (30 mins and its all brand new rust - just a thin layer though) after rinsing the HCl out before doing the sealer.

Another prob was getting liquids out of the tank - all the openings are at least 1" in from any side wall for the cibby - makes it incredibly difficult to drain the last bits out. Get a small pump and hose to drain it out properly.

BTW - having 'marine clean' on your paint work for a few seconds cleans/brightens it up no end. Not recommended though.

[FlyingDutchMan]

Heres a rant I had about what petrol to use in the CBR250 on another forum. Informative even if you don't have a CBR250.

http://www.cr-x.org/cbr250/forum/topic.asp?TOPIC_ID=29263

[Monsterbishi]

isnt "race gas" expired aviation gas, so it 100LL ?? spose it depends on what "race gas" you buy/use

Race gas is actually just re-named avgas, it's not expired at all actually, it's loaded with lead though, so I'd be hesistant to use it on a CBR250 for fear of what it may block along the way...

We've always run 96/95 in our MC19, never had any foulling issues. Main reason being that we live by the simple rule that if the engine has a compression ratio of 10:1 or higher, it should be run on high octane fuel, with the CBR's 11.3-11.5:1 ratio it's right up there, especially with the amount of advance in the ignition system.


That's $80(parts) plus another $60 (labour) for a set of fouled plugs.

Use 91.

Or you could just pull the fouled plugs out, clean'n'gap them and put them back in, which would cost all of $0.00

I can never understand people who think that a fouled plug means it needs replacing, it's right up there with anyone with a non-efi(well, anything without a knock sensor) bike thinking that higher or lower octane fuel gives them any better economy or more power. Octane rating determines one thing only, the point at which it ignites without the need for a spark. And whilst higher octane fuel does have a slower moving flame front, it's barely measurable on a small engine.

[_intense_]

You're much more likely to carbon them up with 98 than 91 simply because it runs too cold. You cannot get more power/efficency out of an engine by running a higher than required. All the CBR250 needs is 91, so you're wasting money by putting 96 or 98 or anything higher in.

AMEN, glad to see some of us have their head screwed on. as for 105... in the famous words of Rove Mcmanus: WHAT THE? run 91 bro you won't pay through the nose, you'll run with no fouling problems (assuming all is well in your engine) and still be able to smoke those pesky boy racers in their cages :2thumbsup