Hi all. Its been awhile since I have been on here. 
Hope all is well!

I want to fit a 76 125c top end on my ct3 bottom end. And my ported 175 top end on anther build 

Are the small end bearings and gudgeon pin the Same size? Should be direct swap? 

And does anyone have a 125c intake? 

Cheers 

www.dropbox.com/s/vpzimx2s073ak9z/IMG_9286-01.jpeg?dl=0

Same rod dimensions.  Use 125 bearing and pin. 

YZ125c intake should be available from aftermarket like DC Plastics...  same bolt pattern as other bikes.  YZ85 intake (angled) might be worth a look...  might be same bolt pattern. 

Perfect! Thank mark much appreciated! 

I actually already have a yz85 intake on my 175 I will have to check in the morning. I swear the yz125 intake looked twice as big 

Should hopefully give me that top end scream I'm after for the street. Obviously if the pipe will allow it. 

Thanks 

You might be right on the reed valve size... I thought it was the 1976 YZ125X where they went to the larger bolt pattern...

I think what it was is the C had the larger pattern already... just a smaller carb mount. X went to larger carb,

If it has the larger bolt pattern you can use an older original aluminum DT2 manifold with a two-bolt rubber flange adapter.

77-79 IT 175 had that larger bolt pattern too. And of course the YZ125C manifold.

hotfootmoto.net/store/home.php?cat=257

Ebay aluminum manifold

The YZ125 C, X had the same bolt pattern as the DT400. So you could install the 6 petal reed of the DT400 into the YZ125 C,X. just by removing material from the castings of the cylinder where the reed valve was housed. (carefully). This mod however resulted in less horsepower because it slowed the velocity down of the gases entering the cylinder. The original reed cage of the YZ125C, X worked best during that time period. For what its worth the YZ100 exhaust was the best exhaust for a performance increase to be used on the C,X model YZ125's during that period, That exhaust greatly raised the top end performance of the 76, 76.5 YZ125's. One of the most beneficial porting mods was to add another boost port facing down into the cases on the intake side to mirror the upward facing boost port already on the intake side. Do not raise the exhaust port height.
 

Thanks for that WRH
​​​​​​I was just going to run stock size cage but run V force reeds. 
Note taken, I have a pipe already on my 175. Hopfuly it works okay with the YZ cylinder 

Will look into that extra port you are talking about also. 

Sent an email with hop up article on the C model.

Hello MarkT,
Any chance I could get a copy of that hop up article for the YZ125C?
Thanks!