I am new to the world of ATVing so forgive my lack of knowledge. I have an '86 Fourtrax 70 and I haven't replaced the oil since I bought it. I believe it has a four stroke engine. What kind of oil should I put in? And is synthetic better than regular (taking into consideration how old the engine is)? Thanks in advance.

 

to check if it is a 4 stroke or two stroke check in manual if you still have it, but it should say on the gas cap mix with oil or what ever, and if it doesn't i'm pretty sure it should be 4 stroke, synthetic is more expensive because its not really oil, regular motor oil is pure almost, synthetic is treated, and will last longer and longer intervals between oil changes but it doesn't mean its good to do it longer, its better to change it fairly frequently like every season, or every 8 months, depends on the riding, but other than that any oil would work just fine, it all really just depends on how hard you ride it, you know. but i wouldn't go synthetic, alot of V-8s can go long with out synthetic, those are for people who like the name and people with sport atvs and sport cars and trucks, or high RPM engines for that matter.


hope that all helps some how.

 

Ok thanks. I don't have the manual but I just ordered a copy off ebay. I saw someone else selling this same quad and they had it listed as a four-stroke engine so I am pretty sure it is. I'll go with the regular oil. Thanks for your help.

 

Use a high quality detergent motor oil with a rating API rating of SE or SF. For correct oil viscocity, it depends on your ambient temperatures where you live. 10w 30 or 10w40 should be just fine[img]i/expressions/face-icon-small-smile.gif[/img] I would't use any type of synthetics, you will get clutch slippage[img]i/expressions/face-icon-small-sad.gif[/img]

And, Welcome to the forum[img]i/expressions/face-icon-small-smile.gif[/img]

 

Oh yea, it only holds . 74 quart of oil or .7 litre.

 

Does the SE or SF refer to whether its a detergent oil or not? And what exactly is a detergent oil? One that cleans out the old oil?

What's the difference between 10w30 and 10w40? How thick it is (with 40 being thicker?)

 

And btw, what is the difference between 0W30 and 10W30?

 

Engine Oil and its viscosity

For satisfactory lubrication of the engine the oil should possess some functional properties of which viscosity of oil is one of the most important properties, as it brings out the oil’s capacity to lubricate. Viscosity is the measure of oil’s resistance to flow. An oil’s viscosity is identified by its SAE’s (Society for Automotive Engineer’s) number. The thinner and oil, lower its number, e.g. SAE 10 W. The numerical relates to viscosity at particular temperature and the alphabet ‘W’, indicates the oil’s suitability for colder temperature. With the viscosity index improver, the viscosity increses at higher temperature and at lower temperature it does not increase significantly, thus achieving optimum viscosity at lower and higher temperature. Such oils are called multigrade oils, for instance ‘20 W40’ shows thinness at low temperature and thickness at higher temperature.

However, there are other service classification of oil apart from viscosity, developed by API- American Petroleum Institute, which indicates service characteristics. It is graded on a scale from SA (the lowest) to SJ (the highest) for gasoline engines, it is graded on a scale from CA to CG. Both the recommendations for viscosity and service classification can be found on label of the oil container.

 

What I sent you came out of the manual. Here's what the SE/SF means:

SE: This category was recommended for certain 1971 vehicles as well as most 1972 vehicles. This classification offers more protection than the SD group of lubricants and is suitable for severe-duty applications. This classification can be used in place of SD oils.

SF: Recommended with 1980 and newer passenger vehicles. This oil has superior anti-wear properties and enhanced oxidation stability over SE lubricants.

Detergent oil cleans the internal parts of your engine.

10w40 operates better in hotter temperatures. Here's the ranges.

10w30: 0 degrees farenheit to 85 degrees.

10w40: 0 degrees farenheit to above 85 degrees

Here's a good site to answer somemore questions you might have
oil questions

 

We have explored the issue of synthetics in Honda autoclutch bikes in other posts, and the conclusion is that a synthetic is ok, although probably unnecessary in your case (although an ester synthetic will clean that thing out real well!).

Use an API SG/JASO MA motorcycle specific oil. My personal preference is Maxima ester synthetic oils. http://www.maximausa.com/