CT-1 175 bore size

[LWC82PE]

What is the standard bore size for a CT1 175 yam?

[cz400]

66 mm, cheers

[LWC82PE]

oK thanks would you have a piston you could measure a couple areas for me?

[David Lahey]

I've got some old pistons that would work in a CT1 that have been used in DT175s and TY175s, but have not got an original Yamaha CT1 piston.
I remember what the CT1 piston looks like, but have not kept one. Does it have to be a CT1 piston to tell you the measurements you want to know?

[Nathan S]

Are you chasing a piston-port one, or a reed valve one? If you're thinking about using a piston-port one in a conversion, be aware that they're quite hard to find (despite all of the Ebay adds for "AT-1 or CT-1 pistons"....).
The reed-valve ones are basically the same as all the other air-cooled Yammie 175s of the 70s.

I've got a used piston-port CT1 piston here.

[LWC82PE]

I need one with no holesor windows in the side of the skirt so this should be like the one one ebay below? If they dont have holes in the skirt, then the next thing i need to know is

total height inc dome
skirt height minus dome
height from top of gudgeon pin

http://cgi.ebay.com/ebaymotors/New-Yamaha-CT1-Piston-Kit-175-Enduro-CT-1-Rings-Pin-Std_W0QQcmdZViewItemQQhashZitem518b856657QQitemZ350233126487QQptZMotorcyclesQ5fPartsQ5fAccessories

this might make it easier. D & B are the most criticle. I already know C is 16mm

[TT5 Matt]

Leith are you making a big er185?from memory i measured a it175d piston against a 185 piston and to correct things you had to machine the bottom of the barrel or top of the cases or find a long rod,it might be in a old thread i started last june