Pro Honda GN4 4-Stroke Motor Oil

You can, but recommend you go with the Owners Manual Specs. Probably 10/40 is the spec but please check it.

My understanding is that it is not synthetic. I run it in my Honda because it calls for it and I think they know it best as the designers.

Yes, but I run the Honda 80/85w HP trans oil in my 07. I think it shifts more smoothly and the clutch works better.

The question is, is your XR100R a 2 stroke, or 4 Stroke. If it’s 4 stroke, then yes Pro Honda GN4 4-Stroke Motor Oil is what to run in your bike. Hope this helps.

I have the 2010 Rancher in So Cal and all the dealers use 10-40 when they changing oil. I asked a couple of them and they told me due to the warmer weather, usually 90+ in the summer. and the riding conditions they always use 10-40 for better protection

Hi Brian. Can't answer your specific question. google that machine specifications and you'll find it. I do recommend that what ever weight they say it is make sure you say with the Honda Oil. I've had several 4 wheelers over the past years and have always used the Honda Oil. The Honda Oil has in it the right additives for the transmission. Regular SAE oil doesn't. Stay with the Honda Oil.

I only use this oil and I use it on 3 wet clutches. It seems to be great for the engines and clutches -- you cannot use regular automobile motor oil, but you CAN use this.

Yes... I have been using it on both sides for years... On my Hondas for years. Pretty sure your shop manual will support this use as well.
Just change regularly... Best you can do. I get 18 -20 hours on my CRF 250 and 450R.. before i change the oil. Track riding.

usually takes between 2 and 3 qts dependent on engine, check ur owners manual or fill to the oil level on the dipstick