5wt oil. Use Honda oil.
Use the weight specified in your owner's manual.
Honda reconmends HP thans Oil SAE 80W/85W
Use a 15-40 W engine oil that is JASO MA or MA2 approved, or equally any SF or SG graded oil that is of similar thickness. For a very worn engine you can use a 40 W single grade oil of the afrementioed specifications.
It is important to use the proper engine oil in a Honda TRX 450 ATV. The manual recommends that top grade synthetic 15w - 30w oil such as Motorex Top Speed 4T Synthetic .
I was told to use a 32 to 1 mix by a bike mechanic
The manual say 20w40 but I use 10w40 normal motor oil with any trouble.
dont really matter. amsoil is good
Just buy it from your local Honda dealer.
You would use 10W-40 Not just any 10W-40 will do it must meet the following Performance specifications:API SG, SL/CF; JASO MA/MA-2; API GL-1
i have an 84 250R and an 85 250R i use 91 octane gas and super M premix I mix 32:1 although u can use 40:1 or 50:1 anytime u change your mix you'll foul a spark plug so carry a few extras so u dont get stuck out in the hills
Polaris has their own special "fork oil". 7.5 weight is equivalent to polaris oil or use a 10 weight to improve dampening.