mixture in my 1998 yamaha yz 125?

Question

hi can anyone tell me what the right mixture of petrol and fully sithetic 2 stroke oil is for the 1998 yamaha yz 125. I recently bought this bike and payed what 2 me was a lot of money and i want to make sure its just right. the bloke i got it from who serviced it regularly gave me some fully sinthectic 2 stroke oil with the bike and has told me he mixed it to a 45/1 mixture but since then i have read the yamaha pucka workshop manual and it states in the spec for this year and model a 30/1 mixture im confused which is right if the manual is right why would he have put 45/1 in it anyone who knows would u please let me know cos i want to use it tommorow and i want it to be right and running at its full power and i dont want to fook it up thanks

i am mixing this manualy myself not trying to set the bikes premix the yz dont have pre mix im mixing this my self

Answer 1

32/1.. i have a 2000 yz125 and thats what that takes

Answer 2

Read the oil bottle, it tells you the right ratio. Just work out how many litres of petrol you have in your tank and add the right amount of oil. It's not really a precise thing, so if it's a bit off, it won't really matter, although you might not get the best performance out of your bike until you get the mix right. You'll pick it up pretty quickly. I had two Yamaha's that needed to have the oil mixed with the petrol, and probably never got it exactly right, but I never had any problems with either of them. In fact, they were the least troublesome of any of the bikes I ever owned.

Happy riding.

Answer 3

Always remember that if you reduce the oil/petrol ratio, you are increasing the petrol/air ratio.More oil equals less petrol so a leaner mix. With synthetic oil, you can usually run a higher ratio petrol/oil mix. I run 40/1 on a motocross bike which I race, but it is a 400. I wasn't aware that engine size made a difference, but I suppose a 125 spends more time "screaming" so may be right.

Answer 4

I used about 32/1 on my bike, during the summer in the heat of the desert. and 40/1 in the winter. Id say 32/1 for yours. 45/1 is way to lean for a 125. you'll prolly have some blue smoke come out your exhaust because 32/1 is a lil rich but its not bad a bad thing. running your mixture to lean will cause your rings to fry quicker. to much oil is better then to lil.

Answer 5

Yamaha and every other Jap manufacturer recommends 32:1
45:1 is a little thin. It may be OK if using the bike for light trail riding. But the engine needs good lubrication when running in the power band (high RPM, MX riding).

Answer 6

well... yamaha preset the mixture in the factory, to stop overoiling and siezure... maybe the guy was just plucking figures out of the air and guessing... but the pump isnt adjustable is it? so the delivery isnt going to be the problem...

on two strokes its either the reeds in the exhaust port clogged with carbon, or the air filter needs cleaning so the engine can breathe. (and mkake sure its got the right plug)

if youre concerned disconnect the auto oiler and put the mix directly into the tank...

Answer 7

32:1 is the best for a 2 stroke that is under a 400cc.

Answer 8

sits 30:1...after you have been riding awhile you will be able to tell the perfect mixture for your bike. you can tell by sound and exhaust color