Yamalube 2S and 2R

[jk50]

It’s funny about those two oils. Yamaha doesn’t say at all that one is only for pre mix, and the other only for injector applications. Some digging and experimenting, I found that 2S pre mixes just fine, and 2R is made by Phillips 66 and very similar, or the same as their AirKool 2 cycle oil. it seems both can be premixed or injector. I’m not sure why Yamaha markets two separate products. 2S is made by ENEOS

[sc00ter]

I seem to recall seeing the 2S is recommended for injector. I thought I had a bottle laying around but it's long gone. I do remember the one recommended for injector had 4 product pictures on it, and a Zuma bug-eye was one of those products. Something about the other oil, has a too thin of a viscosity and will back drain in the injection line, or something along those lines. But I've used the 2S in all of my injected Yamaha Zuma 2-strokes, from mild tuned to extreme tuned, and have never had a problem. Good stuff and I can get it locally.

[jk50]

I stopped using Lucas because I suspect it was causing oil flooding. Perhaps they put their tackifer in the oil. It slings around the crank in great volume, when you shut it off it all pools in the crankcase. Upon restart and accelerating all of that gets sucked into the cylinder and it ran terribly for a while till it burned off. I noticed this as the factory fill oil was being used up and I suspect the Lucas was starting to be used from the bottle. The weather has not been good lately to test my theory. I have 2S in the 70cc kit buddy (still putting it back together) and Phillips 66 in the stock one. I plan on adding 1/2 an ounce extra oil per gallon to supplement the oil pump on the 70cc one.

[sc00ter]

All I can say is I've had great results from the Yamalube 2S oil using the auto-lube pump. I'm going to ask though:
Did you do a leak down and/or pressure check after installing this BBK?
Did you collect any data such as head temps with the stock set-up for comparison with the BBK data?
Did you start with over-jetting the main and work down in jet sizes?
Did you re-torque the head after a few heat cycles?
Do any plug chops? (I never do.)
I've built my fair share of BBK kits and still get something wrong, but thankfully it's a much rarer occurrence nowadays. But anyways, Yamalube is good stuff.
One thing to note: I've never did a BBK on a Buddy 50 BUT is there a chance you could have pinched the oil supply line putting the cylinder shroud back on? I know the Zuma is prone to this and have seen it happen more than once.

[jk50]

Have not started the 70 up yet. I have a temp guage but, I intend to hook it up after break in, and when temperatures are warmer. Jetting is what sigma 6 recommended as a starting point 82 main 35 low. 82 is about 35% bigger than stock 75 (based on area)