Dirt Bike Oil Questions

kenimpzoom

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Jul 13, 2002
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I have two dirt bikes with lubrication questions.<br /><br />1976 125cc 2 cycle Kawasaki - what kind of oil to use for the gearbox? Manual says use "SE Class SAE 10w30". Is this regular motor oil, or is it non-detergent type? What do you reccomend for smooth shifting, is synthetic OK?<br /><br />New Chinese 50 cc 4 cycle- Website says to use "1040, 1540 motorcycle oil. DO NOT use regular motor oil". What is the difference between motorcycle oil and regular motor oil?<br /><br />What is "grade 70" 4 stroke motorcycle oil that I saw in the auto parts store.<br /><br />Thanks, Ken
 

Stumpknocker

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Dec 11, 2003
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Re: Dirt Bike Oil Questions

The difference between regular oil and MC oil is that you are using a wetclutch in you bikes. At least the Kawasaki is and I assume the Chinese guy is too. The argument is that the regular oil could maybe possibly cause clutch slippage. MC oil has no additives that could hurt the clutch or wetclutch. Get oil that is JASO approved. Synthetics should be fine. I use only synthetic in my Kawasaki. I'm not sure what they mean by SE except that your manual is about 18 years out of date with oil designations. Use a reg 10W30 in the gear box or a synthetic oil if it is separate from your engine oil. I use 20W50, some use 15W40 or 10W40 in the engines. You can use obviously, 10 or 15W40. Just make sure its JASO approved meaning ok for a wetclutch. If your smaller bike is 4 stroke maybe its not necessary. Honda 4 stokes like the Goldwings do not have wetclutches. They can use regular oil because of it. However, by using JASO approved oils in it you can't get hurt.
 

BillP

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Aug 10, 2002
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Re: Dirt Bike Oil Questions

"SE Class SAE 10w30" is detergent auto oil...Standard fare for 2 & 4 strokes back then. One of the bike mags did tests on various oils in the late 70s. They found using a higher than recommended vicositiy made air cooled bikes run hotter...too hot. We all changed back from 20-50 to 10-30 after that.
 

one more cast

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May 6, 2002
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Re: Dirt Bike Oil Questions

grade 70 is straight 70 weight. And is for people that think heavy is better. Not me. Also motorcycle oil is made for " hotter running motorcycle engines" But tests prove differently.This test was done by MCN (motorcycle consumer news) and they do not advertise in there magazine so they are not swayed in any one direction.<br /> http://www.nightrider.com/biketech/oiltest1.htm <br /><br /> EDIT: Sorry,these tests were for 4 cycle engines but I thought I would leave the post for others who may be interested.
 

roscoe

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Oct 30, 2002
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21,758
Re: Dirt Bike Oil Questions

Spend the couple extra bucks each year and get an oil made for cycles with wet gear boxes. Something like Spectro Golden4 would be perfect. Most Honda, Kaw, or Yamaha dealers will have it.
 

kenimpzoom

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Jul 13, 2002
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Re: Dirt Bike Oil Questions

Thanks guys for all the info.<br /><br />I'll pick up some 10w40 motorcycle oil in the bike shop.<br /><br />I remember now about the wet clutch, the Kawasaki definately has one, not sure about the Chinese.<br /><br />The Chinese 50 cc is for my 8 yr old son. Bought it for 350 bucks new from Pep Boys. You just cant beat that price, considering we wont ride it that much.<br /><br />Ken
 

LubeDude

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Oct 8, 2003
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Re: Dirt Bike Oil Questions

You have recieved good advice, what you do "NOT" want is additives like Moly in the oil, (Friction modifiers), MSDS sheets are about the only way you are going to fing out if it has it. Just buy Motorcycle oil and you will be fine, Most Synthetics dont have it either.
 

rwise

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Jul 5, 2001
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3,205
Re: Dirt Bike Oil Questions

Back when I did the dirt bike thing I ran a product called "gear saver" from the yamaha dealer, never had trany or clutch problems!
 

Mark42

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Re: Dirt Bike Oil Questions

I'm sure everthing I did prior to the age of 18 was 100% incorrect. So I won't tell you what I used.
 

Triton II

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Nov 23, 2004
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2,479
Re: Dirt Bike Oil Questions

kenimpzoom,<br />Motorcycle oils do differ from automotive oils in that they have shear stabilisers added to the base oil, be it mineral or synthetic. The stabilisers go some way to preventing the long polymer chains within the oil being sheared into fragments by the gearbox of the bikes... most modern fourstrokes share the engine and gearbox oil, hence this requirement. Your Kawasaki's gearbox will operate nicely on any motorcycle specific gearbox oil, the modern synthetics tend to be thinner and improve the gearchange. I used to use Motul synthetic 10W-30 racing gearlube in my RS125 race bike. Chinese thing? No idea, just pray for your son's sake it doesn't break... here in Aus we have heaps of the things and the importers are a bunch of shonks with no spares back up.
 
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