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Author Topic: So what to do with the 125?  (Read 1202 times)

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Offline msambuco

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So what to do with the 125?
« on: July 16, 2018, 08:32:15 PM »
My youngest (now 17) is more interested in the 250's these days. The 125 is never going away. So what do I do? Interested in a build of epic proportions. Think money is no object but not going to waste a penny on anything that doers not add real value. Don't want a "Pro only" powerband that is peaky and hard to ride but willing to sacrifice a little to get some more top end. Me and the boy's know how to punish the poor clutch to make things happen.

So any advice on this? Bike is a 2012. FYI we are talking engine only. More than satisfied with everything else. And no oversize kits. Will always be a 125. After all that's what makes it fun, right? 8)
08 373 Fuzion Toyhauler
1 wife, 2 kids, 1 dog
A lot of toys
A map and a credit card
A lot of memories no one can take away

Offline beaner

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Re: So what to do with the 125?
« Reply #1 on: July 18, 2018, 09:31:40 AM »
You don't say what kind of bike it is but you don't leave many options.

Porting, compression, pipe and maybe see if you can get some oversize or rough power valves and grind them to fit better for more low end power.
Ontario, Canada

Offline msambuco

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Re: So what to do with the 125?
« Reply #2 on: July 18, 2018, 08:00:56 PM »
Sorry, left out that is a Yamaha ;D
08 373 Fuzion Toyhauler
1 wife, 2 kids, 1 dog
A lot of toys
A map and a credit card
A lot of memories no one can take away

Offline Coop

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Re: So what to do with the 125?
« Reply #3 on: July 19, 2018, 04:57:56 AM »
Since making it a "big bore" is not an option I would probably do some porting, mill or change the head (Bud, Harris, Langston, etc.), maybe reed cage and reeds, change the pipe, get timing and jetting perfect, and let her rip.

For the record this is what Harris performance does to their top tier YZ125. I am not affiliated with them, just sharing info.

YZ125 Mod Stage 3 National Package | $3500
The fastest yz125 available, period.  Our 125's have won national titles, holeshot mammoth, glen helen, and regionals.
-Porting stage 3
-Custom billet HP head
-Reed cage
-Custom HP piston
-Crankcase coatings
-Case blueprinting and assembly
-Crank super true, welded crank pin
-Superfinished transmission
-Custom programmable ignition and special powerjet carb conversion, carb mods
-Dyno tune and break in
- Mike - Don't take life so seriously, nobody gets out alive.

Offline msambuco

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Re: So what to do with the 125?
« Reply #4 on: July 19, 2018, 05:57:10 PM »
I was thinking $1500 to 2000. Gotta hide it from the wife. Along with the new rear end and fuel injection needed for my old car!
08 373 Fuzion Toyhauler
1 wife, 2 kids, 1 dog
A lot of toys
A map and a credit card
A lot of memories no one can take away

Offline rsmith

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Re: So what to do with the 125?
« Reply #5 on: July 24, 2018, 06:39:05 PM »
I'd add a Lectron carb to the above list.

--Ron.

Offline msambuco

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Re: So what to do with the 125?
« Reply #6 on: August 22, 2018, 06:19:10 PM »
This is not a dead end here, just waiting for cooler weather to come to FL to get back into our season. Appreciate the replies. Also distracted by the 2 650HP two strokes getting added to my toy box. Regardless the 125 is the most exciting engine ever built ever! Should start the tear down mid October and then be able to send out the cylinder and head to Pro Circuit. Kind of old school due to age and they are tried and true. If we get 3 more ponies without making it hard to ride it should be worth it.
08 373 Fuzion Toyhauler
1 wife, 2 kids, 1 dog
A lot of toys
A map and a credit card
A lot of memories no one can take away