Hey guys,
  I'm about to change the oil in my 1981 Yamaha XT250H. But I don't know what kind of oil to use, and I dont' have a manual, nor do I have the money to buy one. So I'm wondering if any of you have any suggestions on what kind of oil to use, I'm thinking 5w30 but I'm not sure. What would you recommend?

20w50 is what i would reccomend during warmer weather.  you do want wet clutch compatible oil as it will destroy your clutch if you do not use it.

Go to your local walmart and grab a mobil 1 motorcycle specific 20w-50 oil,  that will be good.

Well ive always ran a 50:50 mix of water and 10w40 in my bikes tranny but 100% water gives u maximum performance for about hal an hour but then it seems to smoke bad... TRUST ME!! Ik wat im talking about, ive gone through HUNDREDS of bikes

Thanks for the help, I went with the 20w50 and it works great. But Ron... I'm not gonna go to WalMart LMAO, you can't get good oil there. I go with AMSOIL or Yamalube.

"I'm not gonna go to WalMart LMAO, you can't get good oil there."

Prove it .

Walmart has a small motorcycle section,  and they carry motorcycle specific mobil 1 full synthetic 20w-50 or 10w-40,  good for wet clutch applications,  its only $9.99 there compared to $13.99-$14.99 at motorcycle shops,  its good oil.