LG, the 56-1 is lots leaner on oil than I would consider with the spectro. Now, remember when i said that your bike is likely very rich and that is why it starts well? You gave me one more reason to think that I am correct. I think your PO kept leaning out his mix to try to keep from looking like a mosquito fogger, kept going, probably fouls plugs still, and it was one of the reasons for unloading his bike. Usually I get them with lots of trick parts added because someone was trying to make the old sled work good again, but finally gives in to someone who has been telling him to just get something new.
My yz's 125's run really nicely on 20-1 mixes. They run very long for 125's too.
If it was mine, i would set the float and give it a short ride. if the jets that you find it in are more than two sizes leaner than what is called for in the manual I would get it back to within one to two sizes of what was in the rig when it was delivered and ride it and see if a plug looked white or bright gray. If not I would ride it and learn something about jetting. First up would be set the float, and put it back on a mix that the builder suggests.
My fears would not be about the former owner jetting for ANYTHING at this point. Second to that my fears of putting it on a 32 to 1 mix and changing the jetting to a dangerous point are tiny. If you do the math, you cant effect a whole mainjet size from dropping from 75-1 down to 32-1.
Anyway, the last guy put some bandaids on this one, as is the normal case, and it is one of the reasons you got it.
That nice rich condition that allows you to start easy cold and idle nice cold isn't your friend after about 10 minutes of brisk riding and a few downhills. Really sucks with ones which are tuned right seem to fly by you.
I just finished a 242 mile drive at 80mph after a long days work so that's the reason I quoted myself, this time! However there are many ways a guy can go to mix your gas. I can say that after 40 plus yrs experience I have found the perfect mixture and I'm not telling anybody!
