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CB160 big bore to 175
Posted: Thu Nov 08, 2012 8:24 am
by Jlovvorn
I just picked up a cylinder and piston kit to take my tired CB160 engine out to 175.
It's basically a 2.0 over kit.
Anyone have any experience with this modification, or concerns?
Seems like I should be able to just tear down the engine, swap in the cylinder and pistons, and put it back together.
Thoughts? Warnings?
Posted: Mon Nov 12, 2012 2:49 am
by G-Man
You might encounter a little clearance problem between the larger pistons and cylinder head. A 175 head does not have the cast iron 'skull' so may be slightly different.
With only 2mm you should be OK. You might need to re-jet the carbs, also.
G
Posted: Thu Nov 15, 2012 1:51 am
by kirbb9
If you bought liners then you will have to press your originals out and then have the
cylinder bored to fit the new liners.
Brady
Posted: Thu Nov 15, 2012 8:21 am
by Jlovvorn
I bought a cylinder with the 2.0 over sleeves already installed, with matching 2.0 pistons and rings.
I am hoping I can crack it open, swap the cylinder and pistons, button it up and be on my way.
It's running strong now with no smoke and 155 each side, so I am a little reluctant to mess with it.
I wonder how much I would notice the upgrade in terms of acceleration and top speed.
Not sure it's worth it.
Posted: Sat Nov 17, 2012 4:09 am
by kirbb9
Okay, that should work, and I agree I would hate to tear that motor apart at this time.
Brady
Posted: Sat Nov 17, 2012 7:45 am
by Jlovvorn
I assume this thing has a nice long shelf life. And I have a spare 160 frame and a lot of parts. Maybe I will start building a racer.
Posted: Thu Feb 07, 2013 1:28 am
by teazer
2mm were offered as a big bore modification and can be bored into stock liners. The crown is fine - if it's a big bore 160 and not a 175 piston.
175 pistons won't fit inside a 160 head.
If your motor is running 155 psi on both sides, I'd keep those pistons on the shelf for the day they are needed.