There are frequent questions on the board regarding the debate between synthetic and petroleum based oil. Just wanted to share a hard learned lesson with my fellow GSers and maybe save some of you some cash and heartache.

Long story short, after consulting several sources I considered reputable I put Amsoil synthetic motorcycle in the bike after 25,000 miles of riding on dinosaur juice. Shortly thereafter the clutch started slipping. I attributed it to wear since the bike has not exactly been ridden gently and it's got some mileage on it. After consulting some clutch companies looking for replacement clutches I found some more conflicting info regarding synthetic oil in bikes with wet clutches.

All Barnett clutches are designed to be used with synthetic or regular oil, but they advise against switching to synthetic once the clutch has some wear on it. The heightened lubricating properties of synthetic oil are great for engines, but make a clutches job more difficult. Synthetic oil will quickly kill a worn clutch. I can provide testimony to this.  

EBC clutches seem to be the closest to a factory replacement and are NOT designed to be run with synthetic oil. EBC also makes kevlar friction plates which will tolerate synthetic, but the standard replacement clutch will not live long in synthetic oil.

Incidentally, I can't find a kevlar EBC clutch kit for the GS and the Barnett costs almost 3x the standard EBC kit. I just ordered a standard EBC (the budget forces it right now or I'd do the Barnett) kit. In the meantime I'm going to drain the synthetic and fill it back up with the old skool oil out of curiousity to see if the clutch stops slipping and I can get a little more time out of it.

i know alot who go half an half, shim the springs,  i put  in an extra steel plate and change springs over to GS450 spings and bolts, seems to hold better.  there is enough room in clutch basket to safly put an extra steel plate.  the GS450 springs are longer and use shorter bolts. never noticed any Spring bind and it deff, grabs better.

interesting point octane, I'm about ready to do a change and I wonder if I should try switiching back to dino for this round to see if there's any noticable difference.  I should mention I'm running castrol synthetic right  now and havent' noticed any clutch issues, but it would be interesting to see if by switiching back if it would grab any differently or better.

jake

Very good, haven't used synthetic.  Probably won't ever now...

Anyways I'm cheaper and the petro is less expensive.

ASLAM.

A lot of people I know have had good luck with synthetic BLENDS, like Motul or Silkolene. The full synthetic seems to be a little too slick for stock clutch material. Tomorrow I'll go for a ride and see if the dino stuff made a difference.

wow...is everyone switching back to dino oil now?

i'm going ot try semi-syn by Motul...it's expensive...but guess it's better than synthetic after reading this...

I am considering doing the switch over to synthetic or a synthetic blend. I was hoping it would help keep the engine cool, especially now with lower gearing I'll be running at higher RPM's. Does this sound about right? Synthetic cools better than dino, or no?

Also, has anyone gona full synthetic and had GOOD results?

Has anyone gonna synthetic blend and had NEGATIVE results?

Let's hear from some more full synthetic vs. synthetic blend folks 

i ran suziki oil for my first 2 oil changes (600 then at 2700 ) then at 4700 mile change i was gonna do amsiol then desided i did not want to spend that much on oil .. why pay 36 bucks for an oil change on my bike . it dont cost me that much to change the oil in my car ! (10 dollors a cort for oil and 6 bucks for the filter )  i use the maxima simi blend 10w 40 and it dose out standing i just changed my oil today (6700)  and it has done out standing . no  cluch problems i have not had to adjust my valves yet . its holding strong and running long  

I don't think I understand why one would use synthetic at all.  I've always been under the impression the only advange is its more stable at higher tempuratures.  I use Mobile 1 in my car because it's turbo'd and regular oil will burn and cake in the cbha.  I've always used the guideline 'if it's not blown, you don't need synthetic.'  Sure, there are exceptions to this, but I'd think it rare a NA street engine needs synthetic.

Does the engine in the GS really get hot enough to condone spending at least twice as much for synthetic?

I use AMSOIL full synthetic and haven't had any issues with it.

The engine runs much cooler amd shifts smoother. i would never go back to dino juice!


Even if it kills the clutch a little prematurely I would rather replace the clutch than do a rebuild seeing that the tach frequently sees >9,000 RPM!


Obviously if you have a abused or worn clutch it will slip with synthetic!

Nothing can beat 100% SYNTHETIC oil! It might be a bit costly, but the advantages of using it always keep my loyal to it.

Our GS is AIRCOOLED, or should I say PRAYER COOLED?    Seriously though, it needs all the help it can get to keep the temps down, especially of the GS500F where the engine is now encased in a fairing! Why do you think they added and oil cooler?

Quote from: LimaXray on April 02, 2006, 06:13:07 PM
Does the engine in the GS really get hot enough to condone spending at least twice as much for synthetic?

Yeah, normally I would agree - but like bulletproofcycle pointed out, the GS is air cooled. It gets extremely hot and I think it needs all the help staying cool it can get. I find myself going on fairly long rides and that poor little engine gets so hot, I feel bad for it. I stop and let it cool down, but still. And the hotter the engine is, the more oil it will burn. Air cooled engines love to burn oil, and the hotter it runs, the more it will burn. And as I mentioned, I am not running a 15t sprocket, which makes my RPM's higher than they were with stock gearing - which makes the engine work a little harder, making it hotter. So I figure a synthetic / synthetic blend can help against the effects of the extreme heat 

I have filled my bike with Castrol Edge 10W-60. (That's right, car oil!)

It has the highest API SM and a ACEA A3 rating (see below).

Its fully synthetic and a thicker than the recommended 10W-40 oil so I only recommend it for people who run their engine hard and/or hot.

My reasoning behind using this is my engine is it runs damn hot (especially on our hot summers here in Australia) and this oil is designed to withstand these high heats.

Now I haven't had the oil in long enough to give it my full endorsement but I've had no problems with it so far and no noticable clutch slip. It cost me $65 AUS for 5 litres (GS500 uses 2.9 litres including the oil filter) so its per litre price is quite reasonable.

Synthetics by nature of their design last longer, don't deteriate as fast, don't form sludge, and offer better protection especially in engines that burn oil (as the oil is made of less additives, therefor as it burns, the composition ratios stay closer to the original spec. In mineral oil, additives may burn off first degrading the oils properties).

When choosing synthetic oils, as long as you don't get a motor oil that is friction modified you should be ok. (Avoid oils labeled as "Energy Conserving" or that have an ACEA rating of A1 as they may cause your wet clutch to slip).

Otherwise if it makes you feel better (but will cost more), stick to a motorbike specific synthetic oil.

Another point, many (including oil companies) recommend is that you DO NOT use synthetic oils in your engines until they have been broken is (about 2000km's) to allow the piston rings to seat properly.

Full ACEA specs are:

    * A1 Fuel Economy Petrol (not recommended for motorbikes with Wet Clutches)
    * A2 Standard performance level
    * A3 High performance and / or extended drain

The theory that synthetic will cause your clutch to slip is a nice theory that does not prove true in reality.  Way too many people are out there running Mobil 1 15W-50, or Shell Rotella 5W-40, in their wet clutch bikes with no problems whatsoever for it to be true. 

jeff

 I run MOBIL 1 SYNTHETIC in all of my machines and have never had any problems . I seen at the stealer this weekend SUZUKI 15W40 SYNTHETIC for $7.00 a liter which is cheaper than WALMART MOBIL 1 15W50 at $8.15 a liter.    CHEERS !

Alright, so I switched over to Mobile 1 10w-30 about 375 miles ago. About 160-170 of those miles included some prolonged periods of 8-9k rpm riding. I haven't noticed any clutch problems, but what exactly should I be looking for? As in, what are the early signs of clutch slippage? Would the symptoms start this early or does it take a while? Like I said, I haven't noticed any problems yet but I want to be able to detect the early signs of it if possible.

So far, I can say only good things about the switch. Very smooth, responsive, and I am sure it is running cooler though I don't really have a way to measure "before" and "after" temperatures. I really like it so far.

Getting ready for my second oil change. before I do it I will take a long ride and measure the temp with an infrared thermometer. Change to synthetic and take another long ride and check temp again. When I get this done I will post results

I use Mobil 1 synthetic (V twin type) in my GS500. Got it at Auto Zone. I use Mobil 1 in my Jeep, Nissans, and lawnmower. I REFUSE to change oil every 3 thousand miles. That is not to say I won't do that in my GS. But my lawnmower gets changed every 2 or so seasons and believe me, down here I mow a LOT. We have about 8 weeks of Winter and then it's Summer again. No probs yet. In my Jeep I used to change at 12K (I use the Mobil One filter too-in autos) but now they make a 15K for about 6 bucks a quart. I use this now. It's seems like we all get indoctrinated as soon as we slide out of the womb. The Doctor is standing there and tells you to be SURE and change your oil EVERY 3K. Ain't gonna happen with me. Jeep has 95K (synthetic went in after the break in oil went out), One Nissan has 130K, and the other has 70K.  It has been said.........that if your engine is high mileage you might not want to consider Synthetic...........because if it leaks...it will leak expensive oil. Mine have all had it since they were shiny babies. Try it. You might like it.
In the "long run", you'll save money!!!

p.s.
ALL run cooler plus you get that added protection upon "startup".

They HAVE to run cooler.......Synthetic is slicker'n owl shaZam!. Just use the right "weight". Go to their website and determine what might be best for "your" application.

Me? well...... I'm a Tight Ass. If I were running a 4 Stroke I would just use Car Oil.Something along the Lines of Shell Rotella. I've never been a Fan of Synthetic Oil.I did use some Lucas Synthetic 2 Stroke Mix oil one time in a Weedeater because they Claimed that you could Gain a Few More RPM's due to less Friction.If I did Gain any Speed it wasn't worth Choking and Gagging over the Nasty Fumes that came out of the Darn Thing.I dumped what was Left back in the Can and dumped it in my truck to get rid of it.Then Mixed a Gallon of my Favorite Valvoline.

I bought my GS at 1300 miles, and kept conventional in it until about 6000.  I then switched to Mobil moto specific synthetic.  I had no problems with it, and it worked great with the stock clutch and the Barnett kevlar I put in.  I think synthetic is very valuable, and worth the extra cost.  But, I think its best to run the bike specific oil.