DT 175 B,C and MX Crankshaft/Pistons

[Loydee]

Hi, is it right that a Crankshaft from DT 175 MX is the same and will go in a 1975 DT 175 B ? Whilst I'm on here are Pistons basically the same or not? Thanks in advance...

[Nathan S]

What's a DT175MX? Are you talking about an MX175?

The short version is that virtually all of the old Yammie 125/175s cranks are interchangable.

The exceptions:
mid 1980s+ DT175s have a longer stroke;
1979+ YZ125s have a smaller diameter taper for the ignition rotor to fit onto;
some AutoLube equipped have longer shafts on the drive side that wont fit under YZ side covers;
the AT1/CT1 type engine use a splined primary drive gear (rather than a single key-way).

If you can avoid those pitfalls, then you can swap cranks willy-nilly.

Pistons are all interchangable, AFAIK. The smaller bore, late DT175 is the obvious exception.

[Loydee]

Yeah just to clarify, the DT175MX is what the monoshock models were called here in Pommieland. I was watching a later (79 "MX") rebuilt crank on eBay and wondered if it'd go in my '75 B. The pics on Yamaha's catalog the crank webs and pistons look well different (79 piston has port holes,75 plain). Anyway though I didn't get it thanks for the vital info, especially as the later engines are plentiful here.
All is not lost as I now also have a running '76 DT 175C to play on, they're like beers - you can never just have the one.......!