Had the same sort of issue a bit with my 172, 900ml seems to work fine in it.

If the gears/clutch is all one cavity, I'm betting 900mls but thats a guess.

If you post your question on Trials Centrals site a fellow called King Scorpian will most likely respond, I haven't caught him in error yet, he's pretty good on Montesa specs for any model & anything.

Greg Harding, forgot to add, no I didn't buy it, the advertised ( surely couldn't be real) price was 90 Euro/British/strange pound things & I'm sure it converts to ridiculous Aussiebucks, think I'll go for a bit of Rh angle silicon pipe of the right dimentions & stick a dust jacketed pod on attached ...

Greg Harding, The air box pictured is actually off the first model 172's & 123's ( from memory) I didn't know about the 247 look alikes or the up ended 247 air box with the straight connector, neither of which offer any needed support ( Imo) the 247 gets away with it (not really) because the front ...

I recently inquired about a Montesa 172 air box, this is what I was looking for.

Greg Harding, I've seen the 247 look alike airbox, however every 172 airbox I've ever seen in Australia is a square plastic box with one corner champered & a foam sandwich for filter, I don't know that they were that gr8 of a box as air intake is very minimal & the sandwich was a dicky sort of ...

I also have many 172 parts for sale or swap

Can someone enlarge on this? my 2013 EVO 250 has the slightest near hesitation just off idle & having checked everything else out to the best of my ability, am starting to wonder about carbon & goop in the exhaust. I try & find a bloody big mountain climb as regulary as I can for clean out purposes ...

Juggle art or circus supply, ones in Melbourne the others in Sydney & there's somebody in Perth whose name escapes me, the ones I'm thinking of a very light bruise pads.