Transmission Oil Choices, What To Pick

[Woody_393]

My only comment is that I wouldn't run it in a smaller bike. The oil is apparently too thick and makes the clutch not disengage. That's what my Brother-in-law saw in his sons YZ85 anyway.

[ClosedCasket]

Originally Posted by belly

i went to the honda/yamaha dealer today, and asked them what they recommended for a yz 125 (tranny oil). they told me "Pro Honda HP trans oil SAE 80w/85W". This is my first 2 stroke bike, so my question is, is this the right stuff? thanks

The guy @the honda shop recommended HP2 OMG!!!!??? jk man

Yeah its the right stuff, 80/85wt mc gearbox lube, 5/10 30 or 40, ATF etc etc, take your pick

You can get any "branded oils etc" online for wayyyy cheaper than a honda/yamaha shop fyi.

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[Dirtbikindad393]

I don't suggest running a 20w-50 in a dirt bike unless it has many many hours on it and the journal tolerences are a little more loose. A 20w-50 oil is a very good weight to run in street bikes such as Harleys.

The most popular oil Amsoil sells for the offroad/powersports community is a 10w-40. This oil is formualted for motorcycles with wet clutches specifically.

I have posted it in another place but it would be appropriate here too. Its a motorcycle oil white paper and will help you know what goes on in our engines and what needs to be protected and why.

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Once you have the knowledge about oils and engine needs choose a purpose formualted oil to maintain your bike and extend the life of your investment.

I recommend an multiweight Synthetic whatever brand you choose.

Of course you know what brand I would like you all to use and I offer special pricing for ATM members.

[JonW]

I run Bel ray Gearsaver in 80w-90 in my 83 RM125. That's what the dealer recommended.
It is very thin like 30wt oil. It isn't like 80w for car and truck rear ends.

[Dirtbikindad393]

One other thing I would like to add to this thread. Yamalube is a highly refined mineral oil, they don't hide that fact it right on the back of their bottle. The thing I want to add is mineral oils have a tendency to harden seals and orings any kind of rubber components in your engine. Synthetics will keep those rubber components hydrated allowing them longer life.

[nd4speed]

Originally Posted by Rockey

There’s a lot of controversy about which oil is best in a wet-clutch type two stroke motor. There are also a lot of options out there to put in that high dollar transmission. Synthetic or Dyno? What weight? And most importantly, can I use automotive oils in my bike?
Lets start w/ Synthetic Vs. Dyno oil. Theres a lot of advantage to synthetic oils. One of the most important ones is lubrication. On a 4 stroke, you are told not to use synthetic on break in. This is because the superior lubrication does NOT allow the rings to seat. For the rings to correctly seat, there must be a degree of wear. So synthetic lubricates better. That’s good. Can it lubricate enough for the clutch to slip? In some instances the answer is yes, we will discuss that later. Synthetic also resists breakdown at high temps, for example, Mobil 1 5w-30, a very light oil, will protect and resist breakdown up to 400 degrees Celsius, which if an engine ever reached it would be a glob of melted aluminum. Synthetic also won’t separate at low temps (below 40) like a heavier weighted dyno oil will.

Not sure what the above has to do with a 2 stroke motor since the crankcase is separate with its own oil.

What's dyno oil? Never heard of it.

A synthetic will cause your clutch to slip.

Regular oil with no friction modifiers. Higher performance engine oils such as API SJ, SL, SM will contain some level of friction modifier. While the friction modifier improves fuel economy, it is not compatible with wet clutches used on motorcycles. The friction modifier causes the wet clutch to slip. This is especially true if the motorcycle manufacturer recommends using only engine oils carrying API SF or SG Service Categories. Many choices like 10w40, 10w30, 20w50, and so on. Or 80w to 90w gear lube found at motorcycle shops. Your preference to weight and how much you want to change it.

ATF type F transmisson fluid works too and is also cheap.

[Woody_393]

dyno oil simply means non-synthetic.

[epoor]

ok this may have already been explained but I really don't understand all this mechanic stuff. I have a 1997 yamaha rt 180. I went to the yamaha dealer in town and picked up the tranny oil they recomended. It is a 20w 40. The only problem, it is 14 dollars a QT. I then went to auto zone. They said I could put a four stroke oil in the tranny as long as it was a similar weight. They gave me castrol syntec SAE 10w 40. It was still 7.50 a QT but better than the yamalube. Will the castrol work?

[Woody_393]

Yes, so long as it doesn't say Energy Conserving in the circle on the back of the bottle (which most 10w40 don't) you are fine to use it. I think the Motorcycle specific oils are the "Best" but as long as you keep the oil changed frequently you should be fine.

[Dirtbikindad393]

Originally Posted by epoor

ok this may have already been explained but I really don't understand all this mechanic stuff. I have a 1997 yamaha rt 180. I went to the yamaha dealer in town and picked up the tranny oil they recomended. It is a 20w 40. The only problem, it is 14 dollars a QT. I then went to auto zone. They said I could put a four stroke oil in the tranny as long as it was a similar weight. They gave me castrol syntec SAE 10w 40. It was still 7.50 a QT but better than the yamalube. Will the castrol work?

Yes you will be fine. As Woody said it best for the high reving dirtbikes we ride I would stick with a motorcycle specific oil. They are forulated for wet clutch use and high heat and rpms. A motor oil isn't spcifically formulated for that. In the RT I am going to assum that your not riding it very hard unless you riding it in the street. Then your running on the upper end of rpms and heat in which case you may think about using a motorcycle specific oil.

[1promodfan]

I use the Honda brand in my clutch system. Why take a chance to save a few bucks now......but later on costing more when replacing the whole clutch??