YZ167 Big Bore/Stroker

Motorcycle Kawasaki KX 139

Please call to order 608-842-0680

Availability: In stock.

Regular Price: $2,050.00

Special Price: $1,750.00


Quick Overview

YZ167 Specifications: Fits 1997-Current YZ125


Product Description

Bore: Yes

Stroke: Yes

Actual Displacement = 166.82cc

Engine Modifications Required:

Cylinder: Bore, Port and Replate with Ceramic Nickel Bore coating.

Power Valves: Machined to match big bore ports.

Head: Rechamber to work with the Big Bore piston and stroker crank. 100 octane suggested for most conditions.

Crankshaft: Stroked and balanced.

Crankcase: Modified to clear stroker crank.

Blueprint: Calculate deck height, squish clearance, trapped volume, port timing and compression ratio and list on your perminant Spec-Sheet.

Notes: This kit requires you to send us your entire engine for modification with kick starter and shifter.

Notes: Prices listed are to install stroker kit parts in good condition engine. Should your engine need rebuild parts there will be additional charges. We will call for approval before we install any parts that will have additional charges. (example: rod kit, mains, main seals, trans parts)

Notes: This is it, the one and only YZ167. It is our most popular kit for the YZ125 and it has been for many years. This kit is very popular with Vet racers of all levels and works well no matter how you ride it. It can be lugged like a 250 or screamed like a 125, it does both equally well. Put a flywheel weight on it and it is one of the best woods engines you will ever find. If you are looking for a budget bike build up the best years for this mod was 01-03 followed closely by 05-Current.


  1. Scot says:

    I have had 4 of these, and they are so much fun you cannot even describe it! My current 167 is an 09 that was set up for torque by MAX POWER, and I ride desert and mountains – I dropped 6 teeth in the rear and up 1 tooth in the front, so it is geared really tall, and it handles everything from gnarly, rocky, 1st gear 2 MPH hills to wide open desert, where my top speed is greater than most 450’s.

    I can do any hill that a 450 can do, unless it is a pure horsepower hill – deep sand or something like that.

    I can take off from a standstill in 6th gear with no major drama.

    Too Much Fun!
    I can turn inside everyone.

    If we get into a boulder patch and get stuck, I can pick my bike up and move it, as it weighs 40 lbs less than most bikes…

    I’ll be riding these til I drop.


  2. SOV says:

    Just Plain Awesome !
    This is just plain awesome. I now have the power to go and do what I want with a 125. I’m an old “master” or “super senior” or whatever you want to call a 50+ racer, and I love the fact that I can have the power to get myself into trouble & the power to get myself back out. Even with a desert tank on it, the bike still weights less than any 450 and most 250f’s. It is just plain fun to ride! My only issue was getting it jetted, but Josh helped me out when I needed it. I put an 11oz. flywheel on and the bike will crawl over most any obstacle. With this flywheel on it , it doesn’t rev out as fast and hitting the clutch doesn’t get it spinning like a 125. I think I’ll get an 8.5oz flywheel and try it. I’m running a Barnett basket and the clutch has never been so smooth, even stock. I run a V-Force 3 and an i-boost and response is right now. I use this bike to desert race and trail ride and am so impressed that I don’t think I will get a bigger bike in the future. THIS IS TOO MUCH FUN!
    Dennis Andreasen
    Andreasen Racing

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