4 stroke "thumper" oil questions? (Yamaha YZ426F)

[sw99]

How come you are supposed to change the oil in these after every other moderate ride (8-10 hours)? It's hard to believe that the oil needs changing after this short of time. I change the oil religiously and it's getting more expensive as we speak. Not to mention the $10 quarts of oil and the $11 filters.

 

[Pablo]

Consider a UOA after the 10 hours, It'll cost you about $20, but you'll know not only if the oil is truly spent, but you'll also see how your engine is doing.

That does seem like a very short OCI.

 

[wileyE]

Wouldn't put all 4 stroke singles in the "hard on oil" catagory. Some new generation race singles have engines that are basically shrink wrapped around the crank. makes them light and compact. It also makes them hold a very small amount of oil. What oil is in there gets whipped pretty bad from windage of the crank (no room for a sump). Combine this with the high rpms they run and sharing the gearbox duty, oil gets beat up pretty bad, thick oil gets beat up worse. I think what the UOA's have shown is quick loss of viscosity, mostly with oils that started out pretty thick. IMO just because the oil went from a 50 to a 40, or 40 to a 30 doesn't mean it's totally shot, or is inferior oil, or the engine is going to see any more wear. I only say that because I know these motors do very well on 30w. But without UOA's your best bet is to change it frequently. Sunrah on here done a great job of showing us in terms of hours on his 250cc.

 

[2005tundra2002yz250f]

Change the oil after every race, or 8 hrs of recreational riding. Use shell rotella t oil to offset the cost of changing so often.
I have a yamaha four stroke, and you have to change the oil if you want the bike to last. Its that simple.

 

[sw99]

quote:

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Originally posted by 2005tundra2002yz250f:
Change the oil after every race, or 8 hrs of recreational riding. Use shell rotella t oil to offset the cost of changing so often.
I have a yamaha four stroke, and you have to change the oil if you want the bike to last. Its that simple.

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Interesting... Everything I have read says that you shound NOT use anything but motorcycle oli in these motors. It has something to do with the fact that the oil is what lubes everything including the clutch. I thought there were special friction modifiers for the clutch. I have been using the specified 10w50 Yamalube oil.

I will definately look into the rotella T though and I appreciate all the input.

 

[Master ACiD]

rotella, as well as most diesel oils in general are wet clutch compatible.

i use castrol diesel oil in my banshee quad.

 

[Sierra24]

I've owned my DRZ400E for a year now and I have only used Shell Rotella T 15W40. SRT seems to be the perfect oil for this bike... not expensive and from what I've read from guys like Sunruh and from talking to other riders, this oil holds up well in 4-stroke off-road bikes. I change my oil every 8-10 hours and the filter every second change. Great oil that's easy to find at a decent price... usually about 12 bucks a gallon at the local Canadian Tire Store...add Canadian Tire money and it gets even better!!

 

[sw99]

This sounds too good to be true... I just paid $10 a quart for the Yamalube. $10 a gallon for SRT, I would change the oil after every ride

 

[sunruh]

and changing the oil after every ride or two is the BEST thing you could ever do!!!

 

[sw99]

WOW, I have been searching for the past two hours and found tons of good info on the diesel oils. I am sold. I'm off to walmart for some Shell Rotella T 15-40 - Thanks 2005tundra2002yz250f!!!

I do plan on changing the oil and filter evry 10 hours. I have a Scott's re-usable filter so that will be cheap too

 

[Blake Sobiloff]

Er, do some reading up on the Scotts and filtration levels, too. You may change your mind about that filter...

 

[sw99]

quote:

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Originally posted by Blake Sobiloff:
Er, do some reading up on the Scotts and filtration levels, too. You may change your mind about that filter...

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Everything I have read had been good on these filters. Do you have any links?

 

[2005tundra2002yz250f]

Just use the stock filters. Have two. One in the bike, one clean ready to go in. You'll find you dont have to change the filter as much as you think. Rotella t and stock filters is the way to go in my opinion.

 

[wileyE]

quote:

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Everything I have read had been good on these filters. Do you have any links?

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http://www.kandpengineering.com/index.html

 

[sunruh]

blake,
it filters better than oem. won't rip or tear. a sliver can't pierce it. out flows oem by a large margin.
care to elaborate?

 

[sw99]

Yea, I am curious too... I don't think I need to worry though, I plan on changing the oil every few rides. Especially since the Rotella is so cheap

 

[tsmay51]

I ride a 2005 KTM 450MXC. The main thing we change our oil so often on high performance off road bikes is the fact we ride them off road. Alot of airborn stuff can get into the oil. It's more a precaution to get the contaminants out of the bike not that the oil has broken down. I use rotella in mine and it only calls for synthetic and I have not had any prob. I change my oil every 4 rides unless it is extremely dusty.