CR125M pipe hassles.

[Quicksilver]

I have been cleaning up and checking over my CR125m in readiness for CD5. One of the jobs on my to do list was to replace pipe, its current pipe is pretty much a throw away, no worries no big deal thought to myself, I have another i'll put it on. Not so simple.
Seems their two different sizes where pipe meets flange. The pipe I need to use is larger. No doubt this wont seal very well. 
Can anyone shed some light on going on?

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[cyclegod]

Its a later model pipe, exhaust diameter went from 54mm to 56mm in 1976. You can use an early pipe on a later bike with the correct exhaust flange but not vice-versa, sorry but it looks like you have to get a new pipe or do some cutting/welding.

[Quicksilver]

CG.
Even if I could track down a later flange? If early flange fits later bike wouldnt same apply other way around?

Spose I could cut peice from alloy can to rap around old flange see if that tighten things up a for while.

[cyclegod]

No, unfortunately.

[oldfart]

Exhaust shops should be able to help out with there expander   ...  take the flange with you to get a snug fit    if it goes wrong at least you have the flange to get correct pipe size

[GMC]

I machine the early CR spigots to 40.4mm ID and 76-77 spigots to 44.1mm ID.
The barrels bolt on flange is interchangable.
I don't think you would be able to expand it that much, better to machine a new spigot & weld on.
It sounds like you have it the wrong way round CG, I suspect you can fit the later model pipe to the early bikes but the early pipe may not fit the later bike as the shock mounts are mounted further forward on the swingarm & may interfere with the muffler. I can't remember how different the pipes are.
I build my pipes the same for 73 - 77 with the only difference being the front spigot.

[Quicksilver]

Thanks guys. Few good options to think about.