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Compression???

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64199 Robert_Tadic https://p.vitalmx.com/photos/users/64199/avatar/c50_IMG_20180606_072739279_1540446562.jpg?1540445623 https://www.vitalmx.com/community/Robert-Tadic,64199/all 06/05/18 3 3

Posts: 6

Joined: 6/5/2018

Location: Hebron, IN USA

8/17/2018 7:54 PM

1988 yz80 just got a new top end and gaskets, was bored up to a 90cc by millennium technologies, haven't broken it in yet, but how much psi should it be after broken in? It doesn't seem like it will gain much compression after breaking it in, I have a brand new ring and piston and bored/honed jug, right now before starting it up to break it in it feels low, really low compared to my 216cc ored blaster (broken in). Any suggestions or does an 80 naturally have pretty low compression compared to a doggish 200cc 2 stroke?

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Bikes/Quads:

1988 Yamaha Yz80

2005 Suzuki Lt80

2007 Honda 400ex

Totaled 05 Blaster

kb228

61852 kb228 https://p.vitalmx.com/photos/users/61852/avatar/c50_48AD01BA_8BE7_43D5_B767_B4A5D12AFA64_1538263085.jpg?1538262140 https://www.vitalmx.com/community/kb228,61852/all 01/31/18 3 74 5773 1

Posts: 5851

Joined: 1/31/2018

Location: Mansfield, OH USA

8/18/2018 5:29 AM

Its a smaller motor. Thats why it doesnt feel like its got a lot. Like an 85 will never be as hard to kick as a 500. And yes compression does go up slightly after break in because the rings will seal better to the cylinder

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Robert_Tadic

64199 Robert_Tadic https://p.vitalmx.com/photos/users/64199/avatar/c50_IMG_20180606_072739279_1540446562.jpg?1540445623 https://www.vitalmx.com/community/Robert-Tadic,64199/all 06/05/18 3 3

Posts: 6

Joined: 6/5/2018

Location: Hebron, IN USA

8/18/2018 8:09 AM

kb228 wrote:
Its a smaller motor. Thats why it doesnt feel like its got a lot. Like an 85 will never be as hard to kick as a 500. And yes ...more

kb228 wrote:
Its a smaller motor. Thats why it doesnt feel like its got a lot. Like an 85 will never be as hard to kick as a 500. And yes compression does go up slightly after break in because the rings will seal better to the cylinder

...more

That's what I figured, thanks for the help

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Bikes/Quads:

1988 Yamaha Yz80

2005 Suzuki Lt80

2007 Honda 400ex

Totaled 05 Blaster