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Opinions needed..144kit + autoclutch =250f killer?

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I have been thinking of making the ultimate 125 for the c class average joe. I have a 06 yz125 that I have just fully rebuilt the only mod so far is a vforce 3reed block, I had a procircuit full shorty system on it and found it made the bike to peaky and loud so back to stock.

I am looking for opinions of the eg/athena 144 kits with a full exhaust sytem to match. I am also considering an autoclutch with the rear brake on the bars.

What do you all think? Also if people are selling their 144+ kits or autoclutch plz let me know. Everones opinion counts however if you have never ridden a 144 do not be negative, I do not like 250fs that is the reason for upgrading a 125

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I have an 05' with the athena 144 kit in it. I love the thing. You still ride it like a 125 but it has that little bit of extra bottom that comes in handy in the slower tighter sections. Allows you to back off on using the clutch quite so much. As far as an after market pipe...I could take it or leave it. The stock stuff is pretty good. Jetting the bike took a little while. All metering circuits were changed slightly when I was done. It runs great.

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I have an 05' with the athena 144 kit in it. I love the thing. You still ride it like a 125 but it has that little bit of extra bottom that comes in handy in the slower tighter sections. Allows you to back off on using the clutch quite so much. As far as an after market pipe...I could take it or leave it. The stock stuff is pretty good. Jetting the bike took a little while. All metering circuits were changed slightly when I was done. It runs great.

how many hours have you had your 144 kit and how often do you need piston and rings? do you run pump gas or race gas or a 50/50 mix? have you had any major problems? did you do the install yourself? thanks

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Sounds good. Who has an opinion on 144kit with an auto clutch? Or an opinion of having actuallu used an autoclutch on a 125? Is there a major difference in power when you install the 144 kit?

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The 144 does not give you a whole bunch of power. And my personal opionon is that an autoclutch on a 125/144 would not be good due to how the powerband is.

I suggest you just ride your 125 and slap a pipe and fww on.

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Cheers: HAS ANYONE EVER TRIED AN AUTO CLUTCH ON A 125?

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also does anyone know if the 125 shares the same parts as anyother year yamaha? Eg secondhand autoclutch from 250/f etc???

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The rekluse will detune any bike, its just the nature of it. The main benefit of an auto clutch is preventing stalls and 125's rarely stall and if they do they can almost always be bump started without losing hardly any time. I just think an auto clutch will kill a 125 or 144. An auto clutch also adds flywheel effect because it weighs more. The 125 doesn't even need a flywheel weight but definetly don't do both. A 144 will add more piston weight and flywheel effect.

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Im presuming that most people think its a bad idea to mod a 125 to make it competetive with the 250fs?

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Im presuming that most people think its a bad idea to mod a 125 to make it competetive with the 250fs?

sorry to say...but its going to take the right rider and certain track layout and conditions before yz125's will be killing 250f's

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Im presuming that most people think its a bad idea to mod a 125 to make it competetive with the 250fs?

It sounds unnecessary now. If your 125 was not keeping up with the 250f because of power advantages, thats been solved with them allowing the 250 2t into competition.

I am sure the perfect mx weapon is somewhere between a 125 2t and a 250 2t, but do you want to spend the money to find it?

I dont believe 144 is enough. 250 (2t)sounds like too much.

I would love to build a 144 as the bikes are cheap and the fun of a good running 125 is about as good as it gets.

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how many hours have you had your 144 kit and how often do you need piston and rings? do you run pump gas or race gas or a 50/50 mix? have you had any major problems? did you do the install yourself? thanks

I have about 20 hours on mine since the 144cc upgrade. I plan on ringing it before my next race but it's still running strong. I run 100 octane gas. I buy 110 and mix it 50/50 with 91 octane pump gas to make it last longer and to cut the expense. I did the install myself including machining the cases (used a rotary file in a die grinder). Had no problems what so ever but it was a headache jetting it. I wish I could remember where I ended up so I could share my settings. From what I've heard, the key to making these things last a long time is to run 100 octane minimum.

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I have no problem spending big money to find out. I hate 250fs. Suggestions as what mods would make the yz125 competative?

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Id say go with the 144 but no auto clutch. The 125/144 needs a bit of clutch work to get the revs where the need to be in certain situations. Id say go with the 144, aftermarket pipe, proper jetting and maybe mess with the gearing a little. Thats as good as it gets.

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