2 stroke oil preference and instructions

I've switched premix without draining the tank all the way... Yamalube to 927, back to Yamalube, then to Maxima K2. Some folks seem to be super cautious about this stuff, but I don't think it matters as long as everything is mixed well.

I'd personally only run 927 in a 125 where the revs are high most of the time. Even when jetted super crisp, that stuff makes a top end rebuild on a 250 a chore.

Yamalube is amazing, but does smell like burned garbage. Been running K2 for years now and it doesn't smell like anything to me. It's pretty "neutral".

​​​​​​Anyway, just drain the tank between tests and don't overthink it.

I've ran Ipone in everything for a long time.  smells like strawberries.

Klotz is the best smelling oil out there, you won’t change my mind. Pick a appropriate flash point and send it. 

x2 on something other than 927 on a YZ250 unless you’re riding the nuts off the thing, and that’s coming from someone who’s burned an uncountable amount of 927 in my 125. I’d be looking towards Maxima’s K2, Bel-Rays H1R, or Motul 800.

Curious why not 927 on a 250? It's all I have ever run on every 2t I have owned since the 90's

I'm sure Moto Tribology will have an even more in-depth answer for you, but here's the skinny:

927 and Klotz are castor-based oils. They are made from the castor bean, which is not a standard hydrocarbon nor a synthetic. It behaves in a different way than basically all other oils. (And it smells wonderful!)
Castor is an awesome lubricant for high-heat, high RPM, non-powervalve engines. It is still the best oil for old MX bikes and kart engines, IMO. It leaves a film on the metal surfaces that takes a lot of scuffing before it comes off - great for cylinders, but not so great for powervalves, where it can leave a sticky, gummy mess. The modern formulas have detergents in them to largely eliminate this problem, but it is still a small concern.
If you choose to run castor, remember that the castor oil film doesn't  really play nice with the film from other oils. It might not give you the best protection from metal-to-metal contact. For this reason, I'd completely drain your old fuel and start over with the Klotz or 927. You will not need to make any changes to your bike.  

For all the reasons above, I do like Rickyisms says and run a high-quality synthetic premix oil instead. My favorite is H1-R at 40:1 in my YZ250. 

You'd be fine mixing and matching pretty much all the oils listed, half a tank here or there, etc.   But always like to drain the tank on the bike completely when switching just so you can actually tell the difference in how the bike runs on each oil since you're doing a hard, 100% cutover as opposed to a long, phased in transition where you can't really tell any difference.

I would drain your tank when switching to a different premix. You will get different opinions but this is a safe decision that eliminates all risk.
 

I have used a lot of different premixes over the last 30 years including all that have been referenced in this thread. The only one that I will not use again is Klotz Supertechniplate. It left a weird varnish like coating inside my transfer ports that I did not like. Only oil that has ever done this on any of my bikes. 
 

I currently use Bel Ray H1R and it’s really, really good. The pistons are heavily coated in oil at tear down, ring groove is clean with no deposits, the power valve is so clean it does not need to be disassembled, and it mixes well with Avgas. 

Big fan of MotoRex oil at 40:1 in my YZ125. Fully stock. Burns cleaner than the Yamalube I was running beforehand 

Much better oil technology now versus the 90’s. 927 leaves a coating that is like no other that I’ve seen and is one of the best premixes as far as protection but burns so dirty, especially in a 250 where most riders aren’t even on the main jet most of the track. Switch to a synthetic high quality oil like I mentioned after your next top end rebuild and you will be impressed with the ease of cleaning come next tear down. 

I just bought another big ol jug of the shit out of habit. I just assumed power valves get dirty. Never seen em really gummed up tho

You can get the same performance of a bean oil, but cleaner, through a double ester synthetic.
 

An example of this would be the Motul 800 Road line (not offroad line), or Repsol Racing 2T oil. Both made for pavement racing. 

Castor oil's been around since racing, and it works. But it doesn't mix well with Anything else. It's not the brand, it's the base. Petroleum, synthetic and castor. Pick one and stay with it.

I run Liqui Moly..............cause its in cool looking bottles !!!  and my bike as a Liqui Moly sticker on the swingarm!!!.....gota match!!!

Klotz and 110 octane gas. It smells good and doesn’t gum up if it sits too long. When I mix it for the RM, it also gets used in my leaf blower chain saws and snow thrower. 

H1R is great stuff, and I never had a mess to clean up like 927 can leave behind.  Had great luck with Yamalube in the past as well, in fact back in the YZ days, thats all we would put in them.  H1R was great in our RM's.....

I use Motul 800v off-road 2stroke, is the road version a better oil then? 

Tom Morgan did my 144 jug, and he recommends either Amsoil dominator, Redline, or Klotz R50. He says those oils use the same base stock as what is used for jet engines.

I'm in the same boat with wanting a good smell, so Klotz R50 it is. It does have a pretty high flash point, so I'm curious to see how the piston and PV look in my 250 that runs it as well.

You won't find a bad Motul product.

I've got nothing to add, except Motul 800 smells good for a synthetic.

Maxima themselves told me not to run 927 in my tc250, instead pointing towards K2 or I think SuperM? If you're Carson Brown it's probably fine, but most of us are sadly pretty far off.

I never had that happen with Klotz. What gas you using and what bike ?  I started with Yamaha r then belray h1r. Local shop has maxima too expensive and Klotz cheaper. Klotz smells great even after riding you can smell it going near the bike. And my sinuses r shot.  I mixed with cam2 110 leaded gas station stopped selling it. Then renagade at the pump 3 gal to 2 of ethanol free.  That mix is 2 yrs old so I add 5 gal of vp c12 in bulk to freshen up the gas.  Stock 04 cr125 with a ikat which helps with jetting if it’s a little off.  I hv it jetted a little on the rich side because of the big temp swings and change in humidity. Bike runs clean top to bottom.  Change pipes with no jetting change , it still runs Great. I usually shift on the bubble but I do some laps screaming above 12K.  Klotz it’s an oil that can handle Professional 125 Level riding. Haha 

I've got 2 kids on 2 strokes.  Pretty fast 10 year-old son on a yz65 and a beginner 11 year old daughter on a 85sx.  I've used maxima superM, 927, and k2.  Son burns 927 great but it drools black out of the powervalve drain.  It didn't do that running superM.  So ill be switching him back to it.  

Daughters bike splooges out muffler something terrible with 927.  She's getting faster but still doesn't rev the bike much.  I've just switched to k2 for her but haven't seen results yet.  

But everyone in here described 927 perfectly in my experience.  

Professional, I was using 100% VP C12 mixed at 28-1. Bike was a 2014 YZ125 with full mod schoolboy 1 motor. 
 

Oddly enough, I only tried this oil because of everyone claiming how good it smelled…

Yep, as others have said , avoid 927...burns super dirty and gums stuff up. 

I've run Yamalube for years and based on my experience it's good stuff.  If you want something that smells racy and burns much cleaner than 927, I'd go with Klotz. 

I'm not selling anything, but I use R50 Klotz

I ran 927 from the late 80's through 2002, on 250's.  Always ran clean and no gumming of power valves.  I did have my bikes jetted correctly.  Maybe the formula has changed since?

Damn that stuff smelled good! 

1. Gather ingredients 

2. Fill glass with ice

3. Pour 2 ounces of Bel💧Ray into glass

4. Add 4 to 6 ounces ginger ale, or club soda. Add more, if needed, to top off glass. Serve and enjoy!

Local shop doesn’t hv it. How is it different than Klotz techplate ? 

R50 is 100% synthetic with scent and SuperTechniplate is 80% synthetic/20% Benol