2007 YZ144 Rebuild

kx254f
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kx254f
Edited Date/Time 1/5/2018 9:15am
Was a little rushed to get it close to complete for a Christmas present but not too shab even so. Going to be a fun bike. I forgot to snap some photos during the bottom end rebuild. Tranny looked good but replaced all case bearings and seals. I'll upload more photos as the bike progresses.

















































































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MX4EVR
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MX4EVR 12/30/2015 8:09pm
12/30/2015 8:09pm
Looks badass
c0ncEpT
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c0ncEpT 12/30/2015 8:33pm
12/30/2015 8:33pm
Looks like a different bike! Good job!
xr70
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xr70 12/30/2015 9:13pm
12/30/2015 9:13pm
Very nice.
GeorgiePorgie 12/30/2015 11:21pm
12/30/2015 11:21pm Edited Date/Time 12/30/2015 11:23pm
Like your style. Did you mill down the cases for your 144?

Love mine. Did the same thing last year. And 2015 was my most memorable and fun year racing since I raced superminis in 2000-2004. Have fun riding that bike!!!!



The Shop

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GeorgiePorgie 12/30/2015 11:28pm
12/30/2015 11:28pm Edited Date/Time 12/30/2015 11:32pm


Milled case...had to replace when my countershaft bearing let go. Those 144s aren't a true bolt on. Make sure you get cases milled on both sides. Otherwise she will grenade. I'm sure you know that but didn't notice any milling in your motor pics. But in also think that was the before pic of your motor. Just making sure you did it I know allot of people that don't and they let go in a couple hours. I have 15 hours in mine. No problems yet.

Again have fun sick Bike!!!
Uncle Tony
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Uncle Tony 12/31/2015 6:30am
12/31/2015 6:30am
GeorgiePorgie wrote:
Like your style. Did you mill down the cases for your 144? Love mine. Did the same thing last year. And 2015 was my most memorable...
Like your style. Did you mill down the cases for your 144?

Love mine. Did the same thing last year. And 2015 was my most memorable and fun year racing since I raced superminis in 2000-2004. Have fun riding that bike!!!!



Hey Georgie is that an engagement ring on the rear cylinder stud?
Uncle Tony
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Uncle Tony 12/31/2015 6:31am
12/31/2015 6:31am
Nice job kx254f!
hvaughn88
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hvaughn88 12/31/2015 6:40am
12/31/2015 6:40am
Bitchin' bike! I really like it.
Flip109
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Flip109 12/31/2015 7:09am
12/31/2015 7:09am
Nice! Best part about it is it's not so did up that you don't wanna ride it. Looks ready to thrash! Can I send you my 450 to clean up??? Laughing
kx254f
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kx254f 12/31/2015 7:54am
12/31/2015 7:54am
GeorgiePorgie wrote:
[img]https://p.vitalmx.com/photos/forums/2015/12/30/117559/s1200_image.jpg[/img] Milled case...had to replace when my countershaft bearing let go. Those 144s aren't a true bolt on. Make sure you get cases milled on both...


Milled case...had to replace when my countershaft bearing let go. Those 144s aren't a true bolt on. Make sure you get cases milled on both sides. Otherwise she will grenade. I'm sure you know that but didn't notice any milling in your motor pics. But in also think that was the before pic of your motor. Just making sure you did it I know allot of people that don't and they let go in a couple hours. I have 15 hours in mine. No problems yet.

Again have fun sick Bike!!!
Well hopefully the previous owner did this. I rode the bike once and it went good. This is my first 144 rebuild. I'm working on a 2012 YZ125 right now. I'm curious to try both out and feel the difference. Not sure how many hours were on the bike before I tore it down. We'll see if it holds up in the spring!
kx254f
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kx254f 12/31/2015 7:56am
12/31/2015 7:56am
Flip109 wrote:
Nice! Best part about it is it's not so did up that you don't wanna ride it. Looks ready to thrash! Can I send you my...
Nice! Best part about it is it's not so did up that you don't wanna ride it. Looks ready to thrash! Can I send you my 450 to clean up??? Laughing
Yea I knew we were going to rip it in the spring so no need to polish and perfect. Excited to make it sing!
theToothPerry
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theToothPerry 12/31/2015 9:14am
12/31/2015 9:14am
Just curious as to what you used to clean the frame? It looks great.
kx254f
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kx254f 12/31/2015 10:49am
12/31/2015 10:49am
theToothPerry wrote:
Just curious as to what you used to clean the frame? It looks great.
I used Napa Aluminum Brightener. It's perfect for the Yamaha 2-Stroke aluminum frames but not the chrome polished frames of other bikes. Coat the frame and wash thoroughly after 20 seconds. Repeat until clean and make sure to wash off the acid because it will make it look like shit in a hurry. Soap or any other bike cleaner will help remove the acid.
GeorgiePorgie 12/31/2015 8:44pm
12/31/2015 8:44pm Edited Date/Time 12/31/2015 8:45pm
GeorgiePorgie wrote:
Like your style. Did you mill down the cases for your 144? Love mine. Did the same thing last year. And 2015 was my most memorable...
Like your style. Did you mill down the cases for your 144?

Love mine. Did the same thing last year. And 2015 was my most memorable and fun year racing since I raced superminis in 2000-2004. Have fun riding that bike!!!!



Uncle Tony wrote:
Hey Georgie is that an engagement ring on the rear cylinder stud?
Yea. Otherwise I guess I'd have 4 of these bikes in my garage. Lol


My fiancé snoops around. But never looks at my bike. Kept that thing on there for a few weeks before I popped the question. She never saw it. Walked by everyday.
GeorgiePorgie 12/31/2015 8:46pm
12/31/2015 8:46pm
GeorgiePorgie wrote:
[img]https://p.vitalmx.com/photos/forums/2015/12/30/117559/s1200_image.jpg[/img] Milled case...had to replace when my countershaft bearing let go. Those 144s aren't a true bolt on. Make sure you get cases milled on both...


Milled case...had to replace when my countershaft bearing let go. Those 144s aren't a true bolt on. Make sure you get cases milled on both sides. Otherwise she will grenade. I'm sure you know that but didn't notice any milling in your motor pics. But in also think that was the before pic of your motor. Just making sure you did it I know allot of people that don't and they let go in a couple hours. I have 15 hours in mine. No problems yet.

Again have fun sick Bike!!!
kx254f wrote:
Well hopefully the previous owner did this. I rode the bike once and it went good. This is my first 144 rebuild. I'm working on a...
Well hopefully the previous owner did this. I rode the bike once and it went good. This is my first 144 rebuild. I'm working on a 2012 YZ125 right now. I'm curious to try both out and feel the difference. Not sure how many hours were on the bike before I tore it down. We'll see if it holds up in the spring!
I don't think he did looking at your motor pic. Might wanna consider saving yourself a 750 dollar cylinder.....do it now. While it's cold.
Uncle Tony
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Uncle Tony 1/1/2016 5:26am
1/1/2016 5:26am
GeorgiePorgie wrote:
Yea. Otherwise I guess I'd have 4 of these bikes in my garage. Lol My fiancé snoops around. But never looks at my bike. Kept that...
Yea. Otherwise I guess I'd have 4 of these bikes in my garage. Lol


My fiancé snoops around. But never looks at my bike. Kept that thing on there for a few weeks before I popped the question. She never saw it. Walked by everyday.
Guess she said yes! Congrats Georgie
twnorton
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twnorton 1/1/2016 6:26am
1/1/2016 6:26am
looks good! Thinking about a 144 upgrade myself, I will probably send it to Eric Gorr.

Pit Row

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kx254f
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kx254f 1/4/2018 1:02pm
1/4/2018 1:02pm
Forgot to add the finished product. Better late than pregnant.

Wish I would have taken more detailed photos but never got around to it... Here's the one I got.



SmokinJoe439
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SmokinJoe439 1/4/2018 1:53pm
1/4/2018 1:53pm
Your center cases don't look clearanced for the larger piston. It's a must do mod other wise your piston at bdc is gonna bang into the cases.
kx254f
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kx254f 1/4/2018 2:23pm
1/4/2018 2:23pm
SmokinJoe439 wrote:
Your center cases don't look clearanced for the larger piston. It's a must do mod other wise your piston at bdc is gonna bang into the...
Your center cases don't look clearanced for the larger piston. It's a must do mod other wise your piston at bdc is gonna bang into the cases.
Yea after reading about that as a result of this thread I ended up putting another YZ125 motor in that I had Millenium port and polish. The 144 didn't seem to be any better than the new motor that's in the bike. Only put a half dozen rides on it with the 144 and when I pulled the motor apart, there was some scuffing on the piston. Came on the bike and never dealt with athena mods. Probably will never again.
SmokinJoe439
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SmokinJoe439 1/4/2018 2:55pm
1/4/2018 2:55pm
The Athena kits are crap the porting sucks my 06 Eric Gorr yz 144 rips much better than stock.
Musky
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Musky 1/5/2018 12:01am
1/5/2018 12:01am
Please post video, Thinking of doing the same thing, but with the gytr kit.
BobbyM
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BobbyM 1/5/2018 8:48am
1/5/2018 8:48am
That bike is TITS. GREAT JOB!
kx254f
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kx254f 1/5/2018 9:07am
1/5/2018 9:07am Edited Date/Time 1/5/2018 9:15am
SmokinJoe439 wrote:
The Athena kits are crap the porting sucks my 06 Eric Gorr yz 144 rips much better than stock.
Have to give Eric A try on the next build. I have another YZ125 that I’ve started. All I’ve done is powder coat the frame and swingarm black this far. Motor is next on the list.
SmokinJoe439
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SmokinJoe439 1/5/2018 10:54am
1/5/2018 10:54am
Yes, the athena aka gyrt kits might give you a little bit more torque over stock. But thier ports are known to be miss matched and the head is off too. They can be good if it's ported correctly etc or you don't want to mod your stock cylinder. Otherwise they are just good at lightening your wallet.

My Gorr 144 kit was ported for more mid/top end and I had the head done as a higher compression race gas only so it would still make good torque and not be flat off the bottom.

It makes more power then stock I had to run a 14t sprocket to correct the gearing. With the stock 13t it would just wheel spin 1st 2nd 3rd gears. I also had to put a fmf factory fatty on it cause the stock pipe was choking it down on the top end.

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