125-200cc What does a stock 125 run like?

Rock. Great feedback and shared experiences, thank you!

Since I don't have a '99 owners manual, referencing a '02 CR/WR 125 OM, and it shows the 400 main and 30 pilot stock, so just assumed my '99 is the same, which I'll know soon once I crack it open to take a look, but I'm definitely thinking so. Still and likely will always use the WR ignition because of the type of riding I will do with this particular bike, so hopefully that 380 will work in conjunction with the 30 pilot. Maybe I should lean the needle pos some? Guess I won't know until I run it at the specific elev and also first tune the a/f screw. I just want the thing to sing and have a nice usable powerband. Did anyone know if the 96 or so mixed octane mentioned earlier I wanted to run will affect much on the jetting side? As in, when using higher octane, how does that affect jetting normally?

Good to hear the needle in these older ones are better than the TMXX that all seem to hate, haha.

Being that I'm 220lbs currently, near 5'10, I'm not a light weight, but should be 200 end of year since I'm tired of dragging the weight around lol, so I think a 165/167 kit is in my future. I do need some lugability, I don't want a light switch, so something with little low and mid, even though I know it won't be much since it's still a 125. So, with tuning and pipe selection, maybe I can get this thing to work well. I'll have such a grip into this thing shortly, a bb kit might be a year or more out. I'm apprehensive to buy an FMF pipe (that works awesome on stock bore) since it will be useless if I go BB later, since they work best with a few other pipes geared toward the extra cc's as this site speaks to. Hmm Guess maybe I can pick up a used one in the meantime, there has to be some FMF's laying around that no one uses anymore after having gone to the BB kits and swapping out to another pipe. We shall see.

Higher octane fuel will cause no issues it can hide some the higher the octane the more squeeze it will withstand before self ignition soo your motors ignition can be advanced a fair bit to get her really singing but if you get lazy or run out of octane booster use normal gas you may experiance detonation caused by lower octane, the mix your prescribing may be a little better than pump but unless your using race fuel 110 oct then i wouldnt worry.
We get 99 at pump in uk thats what i use every day.

Thanks Juicy. Sounds like I have nothing to worry about then with that race % concoction and jetting. I'll leave timing in place, since I'm sure standard 91 prem fuel will be used from time to time too. 99 at the pump, wow...sweetness!

Thats shell advance its more expencive but worth it.

so octane question
is it RON, MON or (R+M)2
there is a big difference

Ron research octane number
Thats what we get at the pump.
Just in case you dont believe.

Ok, FattyFat on the way! And no, that's not a new and improved Fatty, haha

View: https://www.youtube.com/watch?v=_kwc9mIDML4