FE/FC Favorite oil?

Just to play devil's advocate here...
The engineers who designed this motor recommend 50 weight.
What do we know happens when an oil is nearing its time to be changed in a bike like ours that shares oil with the gearbox?
Viscosity loss from "shearing".
I imagine when the interval is up, the oil that started as 50 weight is now around 40. Which, the engineers say...isn't heavy enough.
This whole 0w40 M1 camp is because they think that a lighter oil gets into tighter tolerances better, which, I'm sorry to say, is laughable.
When it gets into these mythical "tight spots" in our motor (that somehow the engineers didn't account for...lol) the oil isn't heavy enough for the anticipated load or stress!
We'll see accelerated wear, but if it's a race motor and you're going to tear it down anyway, maybe you don't care.
Me, I'm going to stick to spec.
M1 0w40 "european car formula" is fantastic oil. Very high quality. I run it in my MB sprinter and my tdi wagon.
I have it laying around in big, cheap jugs. I'm not gonna put it in my bike though. In my mind, ignoring spec and giving pseudo-engineering reasons for that is like if you were a concrete contractor and you were hired to do a driveway and the homeowner insisted on using gravel, not sand, under the slab because he has a big old pile out back that he got for cheap, and he read on the internet that it doesn't matter.
You, being a professional who very much knows what he's doing and have been doing this for a long time, try to tell him that there's a reason you use sand under a slab, it will keep it from cracking, and sand wasn't just arrived at all willy-nilly by people taking a random guess.
But ultimately, he's the homeowner!

The engineers can't do anything but unequivocally spec the oil the motor needs for it's anticipated loads. The consumer running another oil of a different weight might work out. Might not.
But I think the biggest factor in people running the M1 is the expense.
If a high quality, ester "true" synthetic, jaso ma2 yada yada 10w50 oil was the exact same cost in 5 liter jugs as the M1, do you really think anyone would run the M1?

No, but how would they be able to payoff manufacturers to install stickers and dream up a specification only achievable by using their special oil? Lol

I'm not saying you have to use BelRay or Motorex, or whatever Virgin Unicorn Tears they're trying to sell us at the moment.
I'm talking about using the right weight of oil.
I promise you, they did not flip a coin when they were figuring out which oil to run.

As for the caved in paper filters, an acquaintance of mine who has been a top level team manager in Baja says that he's seen caved in oil filters before and it's from not getting the bike good and hot before you whale on it. Not too heavy of an oil.

Same here.

I use rotella in my bikes that are more forgiving. My DR650, DRZ 400, etc.
Of course, those bikes are spec'ed 40 weight, so...

Benduro,

Whats the extent of your motor building experience on motorcycles?

So can anyone post a thread about the top end failures of the fc race bikes. A couple have mentioned it earlier in the thread...just curious

Sorry, I call BS on that one. Have you been listening to Ty?

I am an engineer and I understand why manufactures place those specifications on their engines, especially KTM. Did you know that KTM used to recommend 10W30 for use in their off road motorcycles prior to their contract with Motorex? Consequently they still do recommend 5W40 in their motorcycles at lower riding temperatures. If all oils were created equally, this viscosity would be recommended across the board.

The only real difference between M1 0W40 and 10W50 is the starting viscosity as M1 0W40 retains it's higher viscosity at high temperatures. It's one of very few oils which have this stability. At startup, the difference between 72cSt and 140cSt is so great that there is a 2 hp loss just turning the Eaton pump. Spray volumes through the #25 oil jets are significantly increased as well as across the rod bearing.

As for the caved in paper filters, an acquaintance of mine who has been a top level team manager in Baja says that he's seen caved in oil filters before and it's from not getting the bike good and hot before you whale on it. Not too heavy of an oil.
Benduro, Yesterday at 1:35 PM House Keeping



Wouldn't it be the same as lighter weight if you have to wait for the oil/motor to become hot???

"if you have to wait for the oil/motor to become hot???"

From my reading.... That is exactly the time frame when you would utilize the better flow rate. When cold, at startup. It's not all about caved in filters. Never had a caved in filter, but I always warm my engines up.

I read it as a contradicting statement. Questions the logic in the post, that's all.