Ever Try a 36MM carb on YZ125? & What bikes Came with 36 MM Stryker Carb?

[Live To Ride Mike]

Looking to boost the midrange on my YZ125 and thinking of trying a smaller carb. I have been advised to use a Kehien 36MM Stryker Carb. Anyone every try either a 36MM Carb and or a have experience with a Stryker Carb?  IS is much better then non stryker models? Bike already has Pro Circuit pipe and silencer, Mototassanari reed cage. I run VP 4.4 in my 4 stroked and had good luck with it in my 250 strokes. Went up one tooth in the rear, plan on going 2 or more. I run tight east coast woods enduro trails. Thanks for reading.  

Edited February 16, 2018 by Live To Ride Mike

[mlatour]

If not done yet, reduce the compression squish band's height,

makes a noticeable difference on how crisp the engine runs in the low-to-mid.

 

My 2010 YZ125 stock was 1.37mm, now reduced to about 1.05mm running 94 octane fuel.

(dome cc's not corrected), it also gained a modest 5psi of compression.

 

'Well built' 125 race engines can run as little as 0.7mm

 

If a '06+ YZ125, the Pro Circuit pipe may not be the best choice for that usage,

I think HGS/BUD Racing makes specific low-to-mid pipe.

Edited February 16, 2018 by mlatour

[Live To Ride Mike]

Thanks mlatour, how did you go about lowering the squish? Thinner gasket? Who makes that? Turn down the head? 

[mlatour]

The 'correct' method would have been to machine it (lathe, milling machine?)

but with limited resources I lapped the cylinder head down using 400 grit sandpaper on a machine shop's granite slab.

By design of the combustion chamber, at a certain point (say removing 0.20mm)

the piston to head clearance doesn't decrease anymore

 

Unfortunately I didn't measure the before / after dome cc's for comparison

but using an online calculator I come up with 0.46cc's of removed volume,

the stock 06+ cylinder head volume is said to be around 8cc.

 

In theory increasing the compression should bump up throttle response and low-to-mid

but oppositely decrease top end-overrev which suits my style of riding just fine (recreational MX'ing).

 

Running a blend of pump & race fuel of about 94-95 octane I'm not worried about detonation, could always re-adjust the ratio if required.

 

If you have access to thinner cylinder base gaskets you could try that route first before committing to shave the head.

Myself prefer to only use all OEM engine parts & gaskets.  (with the exception of Boyesen reeds)

Edited February 17, 2018 by mlatour