Fuel and ignition questions for zxr250

[NinjaBaby]

Hi All,

I have a 1989 zxr250a and have a couple of questions about fueling and ignition timing for this bike.

1. Does anyone know what RON fuel Japan was using in 1989? Did a bit of a web search and it appears it was probably high 98-100 like it is now.

2. When the zxr250 was complianced for Australia, did they change the ignition timing to account for 91 octane fuel here?

3. If so, is it possible to adjust ignition timing on these bikes? I assume they must have a crank or cam angle sensor of some sort somewhere but can find no reference to timing adjustment in the manual.

FWIW I have tried running the bike on 91, 95 and 98 and can't really notice much difference so am using unleaded 95 at the moment as a middle ground to be on the safe side regarding pinging.

Cheers,

NinjaBaby

[SocialSecurity]

98-100 RON fuel would have been the bees knees in japan in 1989 (like it is now) and only turbocharged vehicles would have required it

AFAIK, the japs have a 91 octane fuel too.

you will get best results with regular 91 RON unleaded, its what the bikes are designed for, JDM or aussie spec... premium will typically make the bike run a little rich, or harder to start in the morning unless you rejet to suit (no point)

only way to change ignition timing would be to get a different timing rotor, or fiddle with the CDI - dont think anybody would make timing retarders for an old 250, and i wouldnt touch the CDI. you dont need to take timing out

[AJ]

i used to run my zx2r on premium, but now i just use regular unleaded, hardly worth the effort to run high octane.

only difference i noted was more kays per tank on premium.

but performance was the same.

[NinjaBaby]

Thanks for the info about the fuel ... looks like I might as well stick with standard unleaded.

As for the timing, I wanted to advance not retard it, to make a bit of power and take advantage of the higher octane fuel available here.

Cheers,

NinjaBaby

[SocialSecurity]

dont think you will be able to buy a timing advancer for your bike (i got one for my zx9r tho)


might just have to live with your 250 till its time to upgrade

[NinjaBaby]

might just have to live with your 250 till its time to upgrade

Hehe, probably ... but it is always nice to pick up some free power (I like bargains when i go shopping too)

[SocialSecurity]

its not "free" if you have to buy an advancer, and a jet kit to get the bike running right on high octane (high density) fuel like optimax, synergy, bp ultimate etc... enjoy

[NinjaBaby]

True if you need to buy electronics but as good as free if you just have to twist a cam angle sensor or dizzy or something

[SocialSecurity]

True... might be possible to advance the timing rotor a tooth or 2, but then probably not. look under the small engine cover on the RHS of the bike. might not be worth taking the fairing off tho

[Nanna10r]

I'd go 98, i heard the japs dont have 91 ron. Its a cheap way to get longevity outta any motor imho.
cheers Brett

[SocialSecurity]

they have 90 RON


i run 91 octane in my ZX9R with a jet kit and timing advancer.