Fuel type and mixture.

[WRT]

Interesting to hear all the tips, I might try running 91 for a bit, see if there is any difference (other than it being a heap cheaper!). Have also run the bike on 50:1 from time to time, without any probs as yet, from what I'm reading here, then I might switch to that full time. Have noticed when running 40:1 I have a little wift of smoke while running, where as with 50:1 I get a small amount of smoke while warming up, and then once hot no smoke. Does this sound normal?

And just as a point of interest, would the different octanes have any effect on running temp?

BTW - TommyD - congrats on your first ride, good to hear you had a blast. Perhaps sing out next time you are heading up to woodhill, I am up there most weekends, can catch up for a ride if you are keen? Or anyone else for that matter . . .

[spiller]

Wow, its interesting to see what people run in their bikes.

I have a 01 cr125, and use ELF HTX 2 stroke oil @ 30:1 with av gas.

I've had bad experiences with Motul 2 stoke oil, but some swear by it.

Woodhill is great, maybe Ill see ya out there!~

[TommyD]

Hey - WRT. Would be good to hook up for a ride sometime as I don't know the tracks at the moment and it would be good to ride with someone with some knowledge (and the same bike). I'll give you a shout when I'm next heading up there. Cheers

[WRT]

TommyD - sweet as, sounds good - same applies for anyone else in the area. Maybe we should all be posting in KB or PM'ing each other when heading out that way? Only thing is I only tend to check this from work . . . not on the weekends.

Also, at the moment, I'm out of action, need new rear axle dust seals (the old ones didnt survive getting removed while checking the wheel bearings . . . ) which I have on order thru Botany Honda - but they are two weeks away.

Gutted . . .

[Cary]

Excuse me, but aren't all 2-stroke bikes self mixing?
Why are you worried about oil|petrol ratio's?

Just ensure the right grade of petrol in the fuel tank and good quality 2-stroke oil in the other tank. Being self-mixing, the bike does the rest for you.

Dead wrong there sure most Road going 2 strokes run an oil tank but off road MX/enduro bikes don't have one. Run straight petrol in one of them it i'll seize in about a km.

This is done so oil/petrol mix can be changed/tuned for performance.

[Stevo]

Dead wrong there sure most Road going 2 strokes run an oil tank but off road MX/enduro bikes don't have one. Run straight petrol in one of them it i'll seize in about a km.

This is done so oil/petrol mix can be changed/tuned for performance.

Two reasons this is done.
a) to save weight
b) because a lot of oilers aren't able to change as well as the fuel rate. ie will under oil at high revs and over oil at low revs and also response time lags a little from what I understand. Hence why race bikes are best on pre mix

[Motu]

With a race bike it's just one more thing to go wrong,they cut the chances of pump failure.On a street bike it's for convieniance,mixing at the pump if it took 6.37 litres is a bloody nightmare.My DT230 has a motor based on the YZ motor,but has an injection pump as it's a street legal bike.Suzuki and Kawasaki street bikes had oil feeds to mains,so it was not a good idea to go pre mix,but Yamaha have only ever used an oil feed into the intake port,changing them to pre mix was easy.In the good old days you could buy pre mix at the pump - BP ZOOM.

[tonyg26]

25mls of castrol 2 stroke racing oil (blue stuff) to 1litre of 98 octane, cant wrong!

[flyingcr250]

Cheers to all for the advice on the fuel/oil mixture. Spoke to a bike shop and they recommended 91 with a 40:1 ratio for a CR250 2001. All seemed sweet at my first outing at Woodhill. I had a blast!

boyds in hamilton told me to run my 2001 CR250 on 35:1 98 octane. i use that CASTROL TTS 2T oil.

[B0000M]

Modern synthetic two stroke oils should be run at the recommended ratio (which is usually 40 or 50 to 1). Ever wondered what that brown crap you scrape off the top of the piston is?

I also don't see what difference octane rating is gonna make to a two stroke. As far as I can see any rating over 90 is gonna suffice...Motu? Any opinions?

funny the posts posted here in 2005 like this one is one id argue, 95 or lower and my cr will eat a piston.

other funny things like "dont all bikes have auto mixing"

something cool i just thought of though that would be awesome would be if they had a button you press on the pump at the gas station that added the correct amount of oil to your fuel. (and it was a decent oil)

[flyingcr250]

funny the posts posted here in 2005 like this one is one id argue, 95 or lower and my cr will eat a piston.

other funny things like "dont all bikes have auto mixing"

something cool i just thought of though that would be awesome would be if they had a button you press on the pump at the gas station that added the correct amount of oil to your fuel. (and it was a decent oil)

i think in auzzie they have pumps like that.