TM250 Stinger length

[ninjamk]

Thanks Lozza, what is the correct diameter?  I haven't measured it in a while but I want to think mine is 1 1/8 in.

[Lozza]

No "correct" diameter but 28mm is on the large for a 250. Diameter is down to how much your piston can handle. Heat in the pipe is down to compression and advance .............etc etc etc  Smaller stingers favour high rpm, but I wouldn't go lower than 26mm

[ninjamk]

Well, I measured it up and its at 25.2mm.  Am I safe to run it that way? Jet on the rich side, retard the timing?   I just want to make sure the pipe is good before I fine tune the jetting.

[GMC]

25.2 will be fine, it's not that critical.
Of all the dimensions in a chamber the length of the stinger is the least critical (within reason)
Stinger diameter is probably the next least critical (within reason)

I would say you have a window of 23-26mm diameter for your TM.
and around 200 -400 long for a stinger.
Outside of these dimensions is getting outside the norm.

Most 250's would run around the 1 1/8" OD stinger which equates to aprrox. 22 to 23mm ID depending on wall thickness