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TY 175 fuel

Posted: Thu Dec 16, 2010 6:43 pm
by Clive.Agi Halls
Just put all new carby seals in my restored TY 175 & the bike is running better. What octane fuel is best? What oil, mineral or synthetic? Have heard these old type motors are not good with synthetic. What ratio as its now premix. Probably knew all this years ago but better get a refresher. I have standard jetting, needle one groove rich. :D Pipe is a WES alloy. Air cleaner is standard. Be glad of any advice from the experts. Cheers Clive

Re: TY 175 fuel

Posted: Thu Dec 16, 2010 11:05 pm
by David Lahey
Clive it is not the age of the bike that determines oil mix and oil type, but whether it is air cooled or liquid cooled, and how regularly the motor is going to get a run.
Air cooled motors run both hotter and colder than liquid cooled motors. Cool is not a problem with oil but to cope with high temperatures, the oil you use should have good film strength at high temperatures. Synthetic oils generally cope better with high engine temperatures than mineral oils.
If you are going to ride the bike regularly and park it somewhere dry, a full synthetic oil would be fine. If it is a twice-a-year bike then go for a semi-synthetic oil to better protect the motor bearings from corrosion than with a straight synthetic oil.
With petrol it is the same as for modern trials bikes - fresh is best and choose premium unleaded but not any fancy bowser fuels designed primarily for fuel injection (they may not have the right SG for a carburettor motor)
For oil ratio you will probably get a barrage of opinions for what is best - ranging from 25:1 to 80:1. Choice of oil ratio is a balancing act between having enough oil to preserve the motor internals from frictional wear and corrosion and oiling up the inside of the exhaust pipe.
For a well-jetted TY175 being used off-road and running semi-synthetic, or full-synthetic oil, I would suggest you use run between 33:1 and 40:1

Re: TY 175 fuel

Posted: Fri Dec 17, 2010 10:12 am
by Clive.Agi Halls
Thanks David, I was pretty much working along those lines but its great to get it confirmed. Sure hope to use the TY more than a couple of times a year but the Beta likes a work out too. Thanks again Clive