5W40 viscosity for motocross bikes

[Sprocket]

Hello, I visit this forum every day, but today I've decided to participe.

I ride a Husqvarna TC 250 2010 and use Motul 300V 15W50, but last week after rebuilding and cleaning it I filled the engine with Petronas Syntium 5W40 from my diesel cars,and I´m surprised because the engine starts quickly, has a little bit more power and the most important, gearbox and clutch runs better than ever.
My question is:

-Are the 5W40 oils too thin for a MX bikes? (temperature range is between 10 to 40 Celsius)
-Can low saps oil be dangerous for the transmission?

Factory recomends Castrol Power 1 10w50, here is 9€ lt, Motul 300V is 16€ lt and this Petronas costs 19€ 5 ltrs and runs better than the others.

Thanks.

 

[Mackelroy]

Are you sure its not just a perception thing, Ive ran 5w40's and motul 15w50, performance wise insignificant, Cold start might spin easier till full warm with a 5w40. However Motul is a much heavier film base than a 5w40, and film strength prevents wear, once up to temp.

I used to do topend runs on a bike, that never got over 96 to 98 mph on 5w40's, oils like motul 15w50 and amsoil 20w50 i could break 100 mph.

 

[ccdhowell]

I run 5w40 oil in my racing quads with good results. At the short OCIs I run, about 3 hours, it isn't an issue. I wouldn't run low SAPS oil in my motorcycle, not enough ZDDP to protect the cam and cam rockers IMO.

 

[Sprocket]

I think is not a perception because when the engine is cold runs "ligther", but in two minuts is identical to 15W50. My impression about the clutch is that Petronas have a lower friction coeficient and clutch works better, but it is possible that it produces slipage in several abuse.
This oil is 14.1 cst at 100 degrees and meets VW 505.1, with this specification the HTHS must be over 3.5 over long loads periodes.

 

[Sprocket]

Originally Posted By: ccdhowell
I run 5w40 oil in my racing quads with good results. At the short OCIs I run, about 3 hours, it isn't an issue. I wouldn't run low SAPS oil in my motorcycle, not enough ZDDP to protect the cam and cam rockers IMO.


Low saps oils have any additives to suply the ZDDP, the TDI camshaft haves poor coating and works with more load than motorbike, or I think so...

 

[ccdhowell]

I have considered low SAPS oil in my quads when I had some left over from an oil change. My wife's Audi TDI uses low SAPS oil, 8.5 L, so I always have a half liter left over. I have run it in my lawn mower, but not my quads. I did notice the high HTHS on the new low SAPS oils for TDI use, they may work really well. Run it a little while and report back.

 

[sunruh]

is your '10 tc250 a black head?
i am thinking it is.

the 5w40 oils tend to shear out of grade very quickly.
i have a friend, ran shell 5w40 for several years and kept breaking 3rd gear in his bike (yz250f). while at the same time i was running shell (and others) 15w40 and i never broke a gear. i have talked with other guys that ran 5w40 and also broke 3rd gear.
all of them have switched to 15w40 and since late '08 or early '09 none of them have broken any gears. yet they still ride just as hard.

you can run the 5w40, i just dont recommend over 5hrs of motor time on it.

if you can find the shell helix 15w40, run that!

steve

 

[Sprocket]

Originally Posted By: sunruh
is your '10 tc250 a black head?
i am thinking it is.

the 5w40 oils tend to shear out of grade very quickly.
i have a friend, ran shell 5w40 for several years and kept breaking 3rd gear in his bike (yz250f). while at the same time i was running shell (and others) 15w40 and i never broke a gear. i have talked with other guys that ran 5w40 and also broke 3rd gear.
all of them have switched to 15w40 and since late '08 or early '09 none of them have broken any gears. yet they still ride just as hard.

you can run the 5w40, i just dont recommend over 5hrs of motor time on it.

if you can find the shell helix 15w40, run that!

steve


All the 5W40´s shears fast?
How is possible than a "basic" 15W40 runs better?
Bad viscosity improvers?

 

[sunruh]

i wouldnt say bad.

just that in a shared sump the tranny tends to cut them up very quickly.

the 5w40s are great engine oils, just not so great tranny oils.

 

[Sprocket]

15 years ago I put in a Yamaha XT 350 the Castrol GTX 15W40,run 200 kms and oil was burned, with serious damages in camshaft.
The Castrol dealer(and oncle)says than GTX cannot run on aircooled engines,but...What is more several whith oil? The XT, XR air cooleds or the new racing MX 250 four strokes?

 

[sunruh]

i dont care about the xt/xr bikes. however, an air cooled bike at its rev limiter will incur a lot of heat.
but those bikes dont rev anywhere near what a 250f does and that is where the real abuse comes from.
your old black head husky is not close to the red head husky and the other 5 colors of 250f.

and i've tested gtx and it is one of the worst oils in terms of shear stability and wear prevention.

 

[Sprocket]

I think my 2010 TC "black head" is fast, equal than the newer japanese bikes, only KTM have more power.

I can buy the SHELL, but only online, if Castrol is bad, and Petronas 15W40 is "not tested"... have Mobil any similar?

 

[sunruh]

list some other brands of oils you can get.

 

[Sprocket]

With a good price only Motul,BP,BelRay,Repsol,Global Racing Oil, Bradol,Putoline,Bardhal,and some Valvoline blends.

Can buy Liqui Moly and Motorex (cross power used in my Husaberg) with important discount, but are too expensive.

 

[sunruh]

how expensive is motul 5100 10w50?
i have tested it with great results.

 

[Sprocket]

Originally Posted By: sunruh
how expensive is motul 5100 10w50?
i have tested it with great results.


Is not expensive, is 30€ for 4 liter. It's half than 300V.

 

[Sprocket]

What is de diference with 5100 15W50?
http://www.motocard.com/sp/aceites/aceite-motul-5100_2l.aspx

 

[sunruh]

i had to find and english site to read the technical data sheets on them.
which, are almost identical.
same cold pour point. 15w has higher flash.
either would be great.

if that is a price you can afford to pay, i would use either of the motul 5100 grades with complete trust.

 

[Sprocket]

I´m going to keep the Motul 300V for the endurance races, and use the 5100 15W50 for every day.
I will use the Shell Helix 15W40 for winter, the available here is HX5. I am surprised for since this mineral oil it is so good.

Thank you very much, especially to Sunruh.

 

[kballowe]

Originally Posted By: Sprocket
I´m going to keep the Motul 300V for the endurance races, and use the 5100 15W50 for every day.
I will use the Shell Helix 15W40 for winter, the available here is HX5. I am surprised for since this mineral oil it is so good.

Thank you very much, especially to Sunruh.


Sprocket -

Sunruh es un experto en aceite de motor para motocross motocicletas de competición. Las motocicletas y las carreras que ha probado muchos diferentes aceites de motor y publicó los resultados de la prueba aquí. Realizar una búsqueda de Sunruh y leer lo que ha escrito.

Translation: Sunruh knows. Listen to him. Read his posts.