What weight oil

[BlackStar]

The Owners Manual on my Roadstar Warrior (Air cooled) calls for 20W-40 oil. The Suzuki manual for my 1978 GS1000 says 10W-40 is preferred, but 20W-50 can be used if the temperature range is correct.

10W-40 seems kinda thin for an air cooled bike in the summer.

I'm curious what you guys are running for oil weight. I don't want to ignite the brand or the synth / Dino wars. Just the weight.

 

[Grandpa]

I've been using 10W-40 or 5W-40 in my GS1100GK for years. It has 118,000 miles with no engine work of any kind. No oil cooler. Oil consumption is negligible.

If your bike is in sound mechanical shape, just use 10W-40, and don't worry -- be happy...

 

[Steve]

By the time it gets a few miles down the road, it's acting like a 40-weight oil, so don't worry about the 10w.

Personally, I would rather use a 10w-whatever at start-up. A 5w- would be better. In fact, I actually use 5w-40 synthetic in my Wing. The thinner oil will travel the smaller passages easier and quicker for better lubrication at start-up.

Keep in mind that the two numbers are for viscosity at a certain temperature. A warm 40-weight oil is actually thinner than a cold 10-weight oil.

If you are in a constantly-hot environment, like the Southern or Southwestern states, a 40-weight oil might thin out too much in the elevated heat, so a 50-weight oil would be better. Except for that, a 10w-40 should be fine.


.

 

[Grandpa]

Personally, I would rather use a 10w-whatever at start-up. A 5w- would be better. In fact, I actually use 5w-40 synthetic in my Wing. The thinner oil will travel the smaller passages easier and quicker for better lubrication at start-up.

I've also been using the same 5W-40 synthetic in my 1100GK (Shell Rotella in the blue bottle, available at Walmart,) for precisely the reason you state: Thinner oil will travel more efficiently in the small passages. I use this oil year round.

 

[rustybronco]

20w50.....

 

[Guest]

The factory claimed that 10-40 disapates heat better than a thicker grade.

 

[twistedwankel]

I've been using 10W-40 or 5W-40 in my GS1100GK for years. It has 118,000 miles with no engine work of any kind. No oil cooler. Oil consumption is negligible.

If your bike is in sound mechanical shape, just use 10W-40, and don't worry -- be happy...

I totally agree with Grandpa 10W-40 is all I ever use in FL at 90F ambient.

Remember that over 75% of engine wear occurs at startup of a cold engine - not at operating temperature when the oil is actually flowing.

I am a believer in Teflon additives over 50,000 miles (and every 50k there after) to reduce wear from that point on. It bonds to the metal surface. (But I have yet to use it in a bike with a common oil transmission for clutch concerns.)

 

[Clone]

20W50 most of the time dino or synthetic, depending on the sales. Often top up with 15W40 because usually have a couple of litres of that lying around because of all the diesels around.

 

[twistedwankel]

10w40....
...re teflon additives-"believe's got nothing to do with it"

It bonds with the metal and has "everything" to do with low friction at cold startup therefore being even more important than low vicosity and metal wear. Too bad it's so slippery it would probably ruin the clutches in the common sump of the GS. Sure works well in all my other engines after they are worn in.

 

[Mark whiz]

If you are looking for an additive that is compatible with wet clutches, this stuff is the bomb! http://www.militec-1.com/

Yeah, it started life as a firearm lubicant (and it is VERY good in that role) but works great in automotive uses too. I've added it to my GS700 with noticeable results in engine smoothness, gas mileage, and even smoother shifting. Also have used it in my cars' crankcases and auto transmissions with similiar results. Yeah, it's expensive - but used to get the military discount so that helped.

 

[twistedwankel]

If you are looking for an additive that is compatible with wet clutches, this stuff is the bomb! http://www.militec-1.com/

Very interested. How much do you add to the GS crankcase? Mine holds 3800ml w/filter. I see it's available in small quanitities too.

 

[Mark whiz]

The recommended dosage for motorcycles is 1oz per quart (liter) of oil. So you would need 4ozs of the Militec.

You might can find it cheaper on some Sporting Goods/Shooting Supply websites. I believe the last bottle I purchsed was from www.midwayusa.com - but that's probably because I get a lot of discounts from them throughout the year.

 

[BassCliff]

Yes, interesting indeed. The website said "Add 2 ounces per liter of engine displacement or two ounces per quart/liter of oil whichever is less for the first 15,000 miles" . In my case I could also use an ounce in the differential and maybe 2 to 4 ounces in the secondary gearbox. A 16oz bottle is $39.90 delivered. Then check out the application schedule. For my riding habits, a once a year application should do the trick

Yep, it's kind of expensive. Would it really be worth it? Or if I change my oils and filter often, is it a waste? Inquiring minds want to know.

Thank you for your indulgence,

BassCliff

 

[Grandpa]

Yep, it's kind of expensive. Would it really be worth it? Or if I change my oils and filter often, is it a waste? Inquiring minds want to know.

Thank you for your indulgence,

BassCliff

BassCliff, to me it isn't worth it. Save your money, change your oil and filter often, ride your 850 long and well, and don't worry -- be happy!

Keep in mind that my 1100GK has 118,000 miles of happy running. Not one of my miles with any kind of additive. Just good oil, serviced regularly.

My opinion, based on 21 years of running GS bikes.

 

[Mark whiz]

Actually BassCliff, the 2oz recommendation is for Industrial/Comercial applications. If you look under "Vehicles" and then the top pop-up "Application Instructions" it specifically calls for 1oz per quart on common sump motorcycles - which is all I ever used.

Grandpa is definitely not wrong in saying that frequent changes with quality oil is all you need to do to keep things as they should be inside the engine. However, if you're someone like me, technology can be a friend too. I use the stuff on my firearms anyway, so it was a simple step to try it in my vehicles as well. It has served me well in all the applications I've tried it in, so I thought I would just "throw it out there" in case anyone else was interested.

Oh, the folks selling the stuff are good quality people as well, friendly and helpful if you ever talk to them.

 

[Grandpa]

Using technology, when not necessary, is plain silly and a total waste of time and money. Whatever advantage, if any, can be derived from adding this junk to a motorcycle engine is subject to the law of diminishing returns. It not only does these additives not help your wet-clutch engine and oil-bath transmission; it may even be harmful to your engine/clutch/transmission.

I strongly recommend to anyone reading this to stay away from anything in your engine other than a good-quality oil changed regularly with the oil filter.

Use of additives of any kind is not recommended by Suzuki. I would think that a motorcycle like my GK, which has been on the road for 118,000 miles, with not a bit of engine, or clutch, or transmission trouble, and no teardowns past the valve cover, is proof enough that this junk is unnecessary and a total waste of time and money.

I'm out of this thread. Waste your money on this junk if you want, y'all. :-D

 

[KEITH KRAUSE]

Use what the factory recommends. On a '78 GS1000?, I'd run 10/40 all year, unless you have a lot of hot summers and city riding to do. 20/50 may be used under hot conditions but be sure you have stock clutch fibers. Many aftermarket plates will allow clutch drag if you run 20/50.
I run 10/40 Motul 3000 all year on my '79 GS1000.