Pre-mix ratio - break-in versus "broke-in"

[spudman]

Hey guys. Well, now that my model 99 Road Toad is up and running, I have a question on the premix ratio. Looking at the owner's manual, they recommended that the first tankful of fuel was to be a 32:1 mix in addition to the oil that was being pumped in from the oil injection pump to "aid break-in". After that, the manual said to use straight premium in the tank along with the 2-stroke oil in the injection tank. I have the injection pump removed and was planning on running Red Line "2T" 2-Stroke Synthetic Racing Oil mixed at 32:1 with premium for the break-in (I just had it bored to .30 over). After that though, could someone suggest a good stable "safe" ratio to mix this particular oil at? The manufacturer says "suggested use of 50:1 but useful up to 100:1". Knowing how the quality of oils have improved since 1975, would this 50:1 ratio be OK in the Toad after break-in? I do have the updated model 02 jetting/tuning in my carburetor. Thanks!

[JayLael]

I'd stick with 32:1 indefinitely if you plan on sustained high rpm high load riding such as street riding. The thinner oil mix ratios work best in short burst scenarios, such as observed trials, where there isn't so much heat build up. Red line is damn good oil, but at 50:1 I had wrist pin bearing failure. It turned blue and came out through the exhaust port, ruined the piston and dinged up the head. Since switching back to 32:1 there have been no such issues. Just my two cents. JL

[spudman]

Thanks JayLael. I'll be riding the bike almost exclusively on the street and I'm just looking for a good ratio that will provide long term reliability. It seems that all this stuff was so much simpler back in '75 when I was 15 and we didn't have too many choices in oil types. The 32:1 option sounds like a good plan.

[Kels]

If you plan on doing prolonged street running.. lots of higher RPM.... I would suggest 24:1 non synthetic oil..

[Bill2001]

On the new top end (rings, hone, piston) on my W'Bat 94 running premix, I'm using Yamalube at 28:1 for the first "couple of gallons" then at 32:1 (4 oz/gal) for post break-in. FWIW.

[MTRob]

On my first two engines 90 and 125 I rebuilt. I mixed 32:1 and after running I started fouling plugs alot. I was using Red line, Super oil. I then dropped down to 24:1 and the plug fouling quit. I can start each bike on the second kick and they run great. I have about 100 miles on both. I wonder if altitude has something to do with it. We are at 4000 Ft. Also have the jetting, pin, float set for this altitude.
Right now I have Taber rebuilding a 94 Wombat 125 for me because I don't have time. Since he is so old he will take his time and should work great plus he is in the same town as me. Still waiting on those clutch savers? In my opinion Red Line is the best oil, Use it in everything I own. My question is do you think Altitude would would effect performance?
MTRob

[viclioce]

Rob. You said "I wonder if altitude has anything to do with it?..." Since your probably not jumping the bike more than 10-15 feet off the ground, you won't be having altitude issues! Just worry about your local elevation! (Sorry, could t resist!)

I'm at 7,000 feet in elevation and am finding I have to jet 2-3 jet sizes smaller for my elevation compared to sea level. So a jet size adjustment of about 10, say from 170 to 160 for each 2,000 feet in elevation. This enables me to go up into the mountains, (I can ride as high as 12,500 ft) and I can get away without rejettimg. Going lower, I take an extra couple of jets with me and go bigger in a minute, especially with the Wombat because it's carb has an easy remove jet bolt. ; D Victor

[MTRob]

I think iam running 180, yes my Wombat is easy to change to so I keep extras also. You must live in Colorado to reach that high in elevation. Here in Montana we can get almost that high here in the Rocky Mountains, But I never have been that far up on the trails.
Thanks Victor
MTRob