I have been told to run my 1990 TY250 pinky on a mix which ranges from 35:1 all the way up to 70:1!

Am looking to see what other people run theirs on please

cheers

I bought a pinky a couple of weeks ago, its bored to 270cc. The bloke I had it off told me to run it at 50;1 mix with synthetic 2 stroke oil. He had run it at that mix since he owned it and the motor sounds fine.

50:1 seems to be winning the vote at the moment! Cheers

Aye 50:1 is correct

I run my 175 at 50:1 right now (did away with the oil injection after it fried the engine once...)

As long as you see a little blue smoke out the back, your engine is getting oil and things are good! I plan on trying the 175 at 60:1 for the next tank I run though it as the Spark plug is still turning fairly black. The spark plug should be a brownish colour. If your plug is white, you're not getting enough oil and you're killing your engine! (just thought I'd add some info in there:))

I'd agree with you at starting at 50:1 and go from there.. if it is loading up and smoking like crazy try moving up to 60:1, or 70:1 etc

I personally wouldn't go much higher than 70:1, but I'm not trying to climb rock mountains with my TY lol. Test out what works best for your machine. I'm sure other people have good opinions on this too which are yet to come

Edited March 30, 200620 yr by Jackman

The oil ratio you use depends on what you use your bike for and the conditions under which you ride it.

For trials work (in sections) the engine doesn't need much oil in the petrol. If however you are going to use your bike to ride along a beach in soft sand, or to cruise up the highway at 100km/h, or to climb mountains that require lots of open throttle work, it is prudent to use more oil in your fuel. As well as the type of riding, it also depends on how hot the air is where you ride and if you ride with mud on the fins. Where I ride it gets extremely hot in summer and some bikes just stop running due to fuel vapourisation problems. You can hear the fuel boiling in the carby. Higher engine temperature usage should be matched with more oil per unit of petrol.

What one person gets away with in their riding conditions may bring on high wear rates and maybe even seizures in another person's riding conditions.

Thanks for that, hot conditions are rare in in England, especially in the Yorkshire Dales where I live so I will take your advice on board and suit the oil content to the type of riding and conditions.

feetupfun is spot on. IF you are doing loads of large throttle opening stuff then add more oil, BUT if you're doing trials stuff i.e. small throttle openings, then I reaffirm my recommendation that 70:1 is more than enough oil. I seem to remember the Yamaha manual recommnends 50:1, presumably to cover mixed riding i.e trashing down the road & pootling in a field/ditch as well as adding a huge manufacturer safety margin, but that was over 15 years ago!!!! As with many things, oil technology has come on a long way since the 80's. Therefore with the quality & protection offered by modern synthetic oils (any brand) there is absolutely no need to add this 'extra' oil - it's just going to gunge up your engine/exhaust/polute etc. I would also suggest that using the spark plug to gauge the correct amount of oil is a dangerous game. Spark plug colour is surely used to determine/record/observe the fuel:air mixture levels and not oil (though of course there is indeed oil in the fuel). Of course be aware that if you change your oil:fuel ratio then you will also be changing your fuel:air ratio. Phew.

I will try to consider the type of riding and adjust the mix accordingly, some good advice which seems to come from a mix of experience, personal preference, techinical info, reccomendations etc.

Cheers