Hello All, I know this has been talked about millions of times but my search results on this site are proving to be worthless for whatever reason.

My questions is I want to remove my oil pump and start running premix. Who here as a DT250 and has done this and what gas/oil ratio has worked good for you for miles and miles of service? I don't ride hard or wind it out very often. I've seen 20:1, 32:1, 50:1. What is best for these motor?  I'm looking for a good all-round mix for an old tired original DT20 with about 4kmiles on the clock.

BTY, I understand how the auto pump works and delivers different mix at different throttle positions. Like I said, I want a mix that will keep the motor happy at normal operational levels.

Thanks

Hey partner....just a question but since you know how the pump delivers a varying amount of oil to the motor based on RPMs and throttle position...then why would anyone want to remove it. Whatever you mix it at will be static and really only right for that set RPM level that the Yamaha engineers designed for that mix ratio.  The experts on here also seem to agree that the pumps are very reliable once they are set correctly. I'm just sayin.....

I did a couple thousand miles using premixed at 32:1 on my '72 CT2 175 before getting the oil pump functioning again. Could probably do less oil with a high performance two stroke oil, but I just get whatever is on sale. Didn't have a problem fouling plugs.

Really depends on what oil. I’d use something mineral like yamalube or supertech at 32:1. I’d avoid super synthetic oils designed to mix at 50:1 or leaner. Lots of oil good. Most modern super oils are not designed for air cooled engines. 

Actually, I’d leave the pump. 

If you do pull it, make sure you remove the shaft and install a block off plate. 

My pump has a slow leak coming from the shaft/plunger. I'm worried if I let it sit to long it may develop air bubbles in the line if the oil leaks out. Even if the pump was working 100% it's still something that nags me knowing if it fails while riding it's pretty much assured that the motor will be fried in short order.
It's not like I can get a new pump and really don' t want to waste my time picking a used one from e bay with no guarantee it works. I figured using premix would give me piece of mind.

I am a fairly competent compulsive tinkerer and still sent my DT360A pump to Mr. DEET for piece of mind when rebuilding my melted engine, he did a terrific job restoring it.  This pump, in combination with modern non-synthetic 2 cycle oil, is really great!

I also bought a used pump on eBay for same and rebuilt it myself just to see if I could...I did and it worked perfectly, but let me tell you that the override clutch pins and springs are beyond challenging to reinstall if you can keep them from going airborne.

I am a huge fan of these amazing pumps that to your point vary output based speed and load.  I would not do premix beyond initial firing up when your validating things like pump output, but obviously this is a personal decision between you and your bike .