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ripcuda · 08-03-2020, 02:12 PM

Stock carb on my HC is the PZ-25 Keihin clone. I slotted the tamper-proof bowl screws with a dremel so I could get to the jets.
The stock jets are 88 main, 32 pilot.
I drilled out the main jet to 90 (mm).

I put one thin washer under the throttle needle (for better midrange).
I also drilled out A/F screw tamper-proof plug and set A/F screw to 1 turn-out.
My HC runs great in stock configuration (w/ stock airbox) with these settings.

But wanting more... I too have gotten a vm22 Mikuni clone carb.
The vm22 fits the stock intake and spacer... but it does have a larger diameter hole than the spacer. I dremeled the spacer to taper the sharp edge where they meet to smooth airflow... but it still necks down a little through the spacer into the stock intake. I've had no air leak issues with the o-rings on the intake/spacer with the vm22.

I have not got my vm22 fully jetted proper yet. Keeping the stock airbox... I did have to lower the throttle needle... as I was bogging badly in the mid range. My vm22 came with a #95 main jet... I drilled this open to ~#98... but it's still not fully reving out for me. Think I need to try #100 next.

08-03-2020, 02:12 PM	#1
ripcuda Join Date: Mar 2015 Location: Spokane, WA Posts: 253	Stock carb on my HC is the PZ-25 Keihin clone. I slotted the tamper-proof bowl screws with a dremel so I could get to the jets. The stock jets are 88 main, 32 pilot. I drilled out the main jet to 90 (mm). I put one thin washer under the throttle needle (for better midrange). I also drilled out A/F screw tamper-proof plug and set A/F screw to 1 turn-out. My HC runs great in stock configuration (w/ stock airbox) with these settings. But wanting more... I too have gotten a vm22 Mikuni clone carb. The vm22 fits the stock intake and spacer... but it does have a larger diameter hole than the spacer. I dremeled the spacer to taper the sharp edge where they meet to smooth airflow... but it still necks down a little through the spacer into the stock intake. I've had no air leak issues with the o-rings on the intake/spacer with the vm22. I have not got my vm22 fully jetted proper yet. Keeping the stock airbox... I did have to lower the throttle needle... as I was bogging badly in the mid range. My vm22 came with a #95 main jet... I drilled this open to ~#98... but it's still not fully reving out for me. Think I need to try #100 next. __________________ '20 TaoTao Hellcat 125 "grommet" '04 Yamaha TTR-125LE '00 Yamaha TTR-90 '07 Kinroad XT200GY Runmaster (sold) '07 KMD GY6 150cc ATV (sold) '07 Kangchao 250cc ATV Monster (sold) Baja Moto DB-30 "Doodlebugs"(x3) (sold) '06 Hi-Bird 200 parts bike (sold)
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