Any Motercycle approved 10W40 oil is good, but you asked for the best: Amsoil MCF with wet clutch protection, iv used it since my rubi was 6 months old and it runs like new!
since your new to the ATV wold, the rubicon is a tad tricky to change the oil on. some advice: Pay special attention to the oil filter holders uppon removel, remember to drain both the tank and engine, and last but the most asked about- to check the oil level run the engine for a few minutes, let it sit for 4 min, then just rest the dip stick on the threads and do not screw it in. This is the correct oil level. Mine takes about 5.75 US quarts.
Ill second the AMSOIL. The starting, the running, the sound, and how many times the fan kicks on and off all improved with this oil. This is my second year on it.
Do a search and youll see when I switched.
But oil is a sticky subject where everyone thinks they are right. And in our own minds we are. good luck.
And a plastic pop bottle is a must for adding the oil. It will screw right into the add hole. Cut the bottom off of course. And a turkey baster if you add to much.
Ahh, another oil post.....you did say "best", so I would recommend Redline as first choice, or Maxima Extra as second.
Pick a motorcycle specific oil that is API SG/JASO MA. The SG insures that it has ample amounts of additives to protect you cam and any gears, and the MA insures it will not make a wet clutch slip. (Note that Redline is JASO MB, yet still ok for a wet clutch...it's a long story!)
Beyond that, the synthetics are superior to plain old petroleum oils (be carefull...there are 3 different types of synthetics), and the Group V ester synthetics are superior to the other two types. (For the record, Rotella is Group III, Mobil 1 and Amsoil are Group IV, and Redline, Maixma, and Motul for example all have some Group V ester based oils.
Another concern of yours should be the coolant.
Me? I just went to walmart and got the jug that said safe for all radiators.
But im sure as with the oil, there will be many opinions and we will all be correct in our own minds.
2001 Honda Rubicon Foreman 500 4x4
