1. all engines have different original "tightness" specs 2. all older Mopes like Tomos and Motobecane are "loose" AND CANT RUN MORE THAN 50-1 THIN. 3. take your STOCK mix ratio and 2x = 100% synthetic mix ratio Old 25:1 = new 50:1 or 2.6 oz per gallon. 4. this only works with 100% synth mix, NOT PART SYNTH OR OTHER BS LABELS 5. the 100:1 on the label is ONLY for (like) new chainsaws that START AT 50:1 and are very "tightly" built inside clearances 6.AMSOIL IS GREAT, CLEAN CLEAN CLEAN AND POWER!!! Just dont run it toooo thin. Now, you dont have to buy and change motor oil so comon, mix it 50:1!