Date: Sat, 27 Mar 1999 08:30:25 -0500
Subject: Oil Mix Chart & TY350 info
From: Chris L Johnson 

>What mix do any of your recommend for a ty-350 using Belray synthetic?
>Also do any of you have a chart showing how many ounces or cc per gallon
at the various ratios?  Thanks >in advance 
>Gary Clemenson
>TY-350

I made a chart years ago.  A nice one at that.  I'll see if I can get it
into an e-mailable format.  Or you can give me your address.

For the TY, I'd recommend 80:1 which is 38 cc per gallon.  People worry
too much about running that lean on oil in air cooled bikes or in
general, but unless you plan on flat tracking your bike, leaner is better
because any more just oil fouls the muffler and does no good.  

You should use 50% racing gas and 50% premium unleaded in your TY.  It
really helps this bike overcome its poor porting and poor heat
dissipation.  

You can also remove the head gasket and carefully silicone seal the
head/cylinder gasket surface with a thin film after cleaning it carefully
and just before reassembly.  Wait 6 hours before starting the bike..  The
lack of head gasket is the easiest way to correct the incorrect squish
band on the Yamaha TY which leads to pinging.

If you are using the TK carb, changing to a 40 or 42 pilot jet over the
stock 37 will increase bottom end.  I don't recall exacly - it's been
years - but I think the stock main is something like a 145, which is too
rich, leading to difficulty revving the motor cleanly.  A 136 is better.

Hope this helps.

Chris Johnson, Director of Engineering
College Park Industries, Inc.
papazit "at" juno.com
www.college-park.com