Ok Gents, looking for advice.

My RS250 is set up for Avgas, which is ok for UK use but cant seem to find a reasonable way of getting hold if it if i want to do a European track day.

Hence, will probably be converting it to unleaded fuel.

Question is ....

I take it the Elf MITS42 is unleaded but high octane for better performance over say Shell Optimax, but how much more performance are we going to get between the two fuels.

Also, if the bike was to be converted for pump fuel, would the head volumes etc still be ok with MITS42?

Any advice greatfully appreciated.

A major benefit with the Elf fuel is/was that it met FIM criteria, and I have no doubt is more highly refined than something such as Optimax. Incidentally, I recall StephenRC45 playing with Optimax in 2-strokes on the dyno, and not quite getting the results that were expected! I'm sure he'll comment later.

Anyway, if you set up for a lower octane (eg. pump unleaded) fuel, and then run a higher octane like MITS42, at worst you may drop off a hp or two, as the two fuels will burn differently, and the setups should be optimised for each condition. However, it's far less likely to cause you problems than if you were to say set up for MITS, and then drop down to 97 super U/L. You'll almost certainly get major detonation going that way!

Setup for the lower octane, more commonly available fuel, would be my advice. You'll laugh, but Tescos are doing 100 octane pump fuel now, and Steve's 75hp MC21 F-III was thrashed by many on a number of track days last year on it, with no ill effects. It's legel, cheaper than AVGAS, and readily available... and minimum delivery is only £1!
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Cheers Andy, like i think i have already said, this is all new to me so any information is very much appreciated.

Simon

Andy's right, Stve has done a bit of research into this for the NSR500s. He did explain it all to me, but I've forgotten exactly what he said.

BP did do a 102 RON octane unleaded pump fuel, but it's discontinued now. I run Avgas in my RS simply cos the bike is set up for it and I can get hold of it easily, but given the chance I'd consider regular pump fuel.

Interesting to see what Stephen says.......

You could try adding Tetraboost which is a genuine lead additive and you could carry it with you to mix with unleaded when you get to Europe. The main draw back is they only sell it direct by the case but i did find a place that sells it by the bottle. If you were interested i could dig out the address?

http://tetraboost.com/
_________________
MC21 300
Aprilia RS250 track bike

Sounds like you are worried about carrying cans of avgas over the water, I done two years at european championships carrying cans of avgas and tollulene, and never had any probs,ten years ago mind and under the water not over it.
_________________
Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto