Author Topic: Back on a eighth liter...  (Read 5191 times)

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Offline Polar-Bus

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Back on a eighth liter...
« on: December 16, 2012, 02:03:08 AM »
So I guess after a 2002 WR250F, and a 2007 YZ450F I finally had to sit back and say "I guess i'm just not a 4 stroke guy" The YZF's are a fun but different type of bike to ride. And when you have an "old skool" pre-programmed 2 stroke point and shoot type riding style, it's frustrating to acclimate to a very different "relax and flow" type 4 stroke style. So i'm done with 4 strokes. Found a nice barely ridden 2008 YZ125 . Very excited ! I should be 100% healthy by spring and my plan is to build a 144cc big bore engine and incorperate a 7oz FWW to see how the power is. My goal is a "fun" and easy to manage engine. I bought an Athena 144 kit, and my plan is to bolt the kit on stock, and see how I like it. Out of the box stock, i'm getting feedback there is not huge gains to be had but everything is interpeted to one's opinion so again we will take things one step at a time. My last 125 was an '89 KX so i'm sure this 08 YZ will slap a huge grin on my face not matter weather it's a 125 or a 144 ! :D  

http://www.ebay.com/itm/Athena-Big-Bore-Kit-Cylinder-Piston-Gaskets-Yamaha-YZ125-05-12-4mm-58mm-144cc-/160939243975?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D4198288824495108206%26pid%3D100011%26prg%3D1005%26rk%3D1%26sd%3D220840109261%26

Here's a few pics of the chassis all striped for an inspection and anti-sieze fest...



And the empty cases waiting for the kit:


« Last Edit: December 17, 2012, 10:34:09 PM by Polar-Bus »
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart

Offline flem469

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Re: Back on a quarter liter...
« Reply #1 on: December 16, 2012, 03:05:34 AM »
You're in for a treat- I race on '05 144 that's been stroked to a 155 by Eric Gorr. It had a 9oz fww, but I don't use it. My suspension is' 06-up with Race Tech gold valves.  Depending on how much you weigh, and the type of riding you do, the torque(yes, on a 125) of the stroker may suit you... I'm going back to a 250 this season, so I'm de-stroking mine for motocross use....

Offline Polar-Bus

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Re: Back on a quarter liter...
« Reply #2 on: December 16, 2012, 04:48:00 AM »
You're in for a treat- I race on '05 144 that's been stroked to a 155 by Eric Gorr. It had a 9oz fww, but I don't use it. My suspension is' 06-up with Race Tech gold valves.  Depending on how much you weigh, and the type of riding you do, the torque(yes, on a 125) of the stroker may suit you... I'm going back to a 250 this season, so I'm de-stroking mine for motocross use....

Excellent ! It took a while for me to find a clean  late model yz125, they're getting very rare, everyone has obviously gone 4 stroke. I specifically wanted an '07+ to get the updated  wave rotors and the plush KYB SSS type suspension. If i'm still not happy with the power after some time, I will send the cyl off to Eric for some porting.
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart

Offline Enginerd

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Re: Back on a quarter liter...
« Reply #3 on: December 16, 2012, 09:25:45 AM »
Excellent ! It took a while for me to find a clean  late model yz125, they're getting very rare, everyone has obviously gone 4 stroke. I specifically wanted an '07+ to get the updated  wave rotors and the plush KYB SSS type suspension. If i'm still not happy with the power after some time, I will send the cyl off to Eric for some porting.
Looks like the start of a great project! I've thought about adapting the '06-up SSS forks to an older bike.  Maybe I still will.

Anyway, lookin good!

Offline Polar-Bus

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Re: Back on a eighth liter...
« Reply #4 on: January 03, 2013, 09:42:22 PM »
All back together,  YZ144 should be a really fun bike to ride this season.





So now that this project is finished, I plan on getting my KX500 kart project going and get back to finishing the starting dillema !
« Last Edit: January 04, 2013, 12:09:33 AM by Polar-Bus »
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart

Offline Foxx4Beaver

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Re: Back on a eighth liter...
« Reply #5 on: January 03, 2013, 10:01:59 PM »
That's lookin sharp Polar!!...I'm assuming you have'nt gotten a chance to take it for a rip yet,since your way has close to a foot of snow.Can't wait to hear your ride report!

Lookin forward to seeing that kart build continue too! :evil:
Excuse me, ma'am...but you've got extremely nice legs!!!...what time do they open???                                                                                                               https://www.youtube.com/watch?v=n8tCgN3aryQ

Offline Polar-Bus

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Re: Back on a eighth liter...
« Reply #6 on: January 04, 2013, 12:03:54 AM »
That's lookin sharp Polar!!...I'm assuming you have'nt gotten a chance to take it for a rip yet,since your way has close to a foot of snow.Can't wait to hear your ride report!

Lookin forward to seeing that kart build continue too! :evil:

It's been SO cold and I have about 5" of snow, it's starts and runs mint, but no I have not yet given the 144 a maiden "beat down"  LOL ! ( but I hear a mild weather trend is on the way !)

I'm itching to get the kart project revived again.... my buddy is supposed to be getting me a old Mopar car starter, i'm trying to figure out if I can fab a mobile 12V starter system like they do with drag bikes.  Gotta figure some easy means of starting the Kong Kart...  LOL
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart

Offline don46

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Re: Back on a eighth liter...
« Reply #7 on: January 04, 2013, 02:44:44 AM »
Many of the hillclimb guys use remote starters, I've seen them on honda 500's and ktm 550's never on a Kawi. having said that I see no reason why it wouldn't work. Most of the guys use Pingel starters, they are compact and can be setup for left and right, obviously in your application you  would have to come off the flywheel
Live today, for tomorrow may never come

Offline Enginerd

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Re: Back on a quarter liter...
« Reply #8 on: January 04, 2013, 05:41:31 AM »
Excellent! It took a while for me to find a clean  late model yz125, they're getting very rare, everyone has obviously gone 4 stroke. I specifically wanted an '07+ to get the updated  wave rotors and the plush KYB SSS type suspension.
I'd really like to find one of these too, but they are as rare as hens teeth around here.

Yours looks great!

Offline Polar-Bus

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Re: Back on a eighth liter...
« Reply #9 on: January 04, 2013, 07:05:59 AM »
Many of the hillclimb guys use remote starters, I've seen them on honda 500's and ktm 550's never on a Kawi. having said that I see no reason why it wouldn't work. Most of the guys use Pingel starters, they are compact and can be setup for left and right, obviously in your application you  would have to come off the flywheel

Yes, this is what i'm leaning towards. I saw a CR500 with a 3/4" nut welded to an old CR flywheel puller. This is what was screwed to the flywheel. Neat idea. The issue with my kart is I will have to drill a hole in the RH side of the seat to allow access to the flywheel nut. But this idea seems the best and easiest. I was also wondering if I could weld the gear to the inside of the kick shaft, remove all the internal kick ratchet mechanisms and spring and weld a 3/4 nut to the kick shaft, and use a 12V remote start ?
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart

Offline don46

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Re: Back on a eighth liter...
« Reply #10 on: January 04, 2013, 11:17:32 AM »
interesting thought, you dont need it to return, not sure what would happen it the shaft was left to go round and round.
Live today, for tomorrow may never come

Offline Polar-Bus

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Re: Back on a eighth liter...
« Reply #11 on: January 04, 2013, 12:47:24 PM »
interesting thought, you dont need it to return, not sure what would happen it the shaft was left to go round and round.

My thoughts as well, the kick shaft is only bushed, but there might be enough trans oil splash to keep the bushing lubed ?
01' KX500
'84 GPz1100
'87 GSX-R  750
'06 HD Fatboy
'73 Kawi H1
'03 CRG KX500 Shifter kart