I killed the master cylinder

[laruetou2]

I'm new to Chinese bikes and new to this forum. Just bot a BD125-10 - it came with many upgrades. No operator manual (which sucks). No parts manual (which sucks).

Was fooling around with it and put my thumb on the round seal or panel (about 5/8" circular) on the aft side of the master cylinder reservoir. It broke and fluid began dripping out. Bad design, but who am I to advise Honda or the clone makers.

Questions:
1. Do I have to pay for an operator's manual. I'm generally used to finding manuals (all kinds) online with no charge for download.
2. Same with parts manual.
3. Can I repair this master cylinder by replacing the plastic panel or do I need to buy a new master cylinder. Where do I get the panel or the new master cylinder? Is there a spec?

Thanks to all in advance,
Larue

[dirtbkr188]

Click HERE and scroll down to find one that matches your brake lever length

[laruetou2]

For those that bot the BD125-10 new, what did you get for manuals and documentation? I'm in bad need of a wiring diagram - front turn signals and brake lights are not working. I've scoured the web and have found nothing. My clone is a 2020.
Thanks,
Larue

[laruetou2]

SPARK PLUG
The Grom manuals recommends two NGK plugs (and Denso plugs) - one with a hotter heat range for tooling around the neighborhood and a cooler one for extended higher speed cruising. My BD125-10 came with a A7RTC which is the equivalent of the cooler plug. Mine is pretty well fouled but the carb plays into this equation so can't blame the fouling on the plug without dialing in the carb.

There is a A6RTC available that is one stage hotter. That might be an option for bikes that seem to run just a tad rich and wont quite dial in.

SPARK PLUG BOOT
The plug (A7RTC) has no cap and the boot apparently slides over the threaded end (the opposite end of the electrodes). But the boot was loose and felt like it could fall off while running (vibration). As a temporary fix, I cut a strip of aluminum foil about 1/4 inch wide and wrapped that around the plug connecting end. It felt better but will probably change out the boot and add a cap.

[laruetou2]

My BD125-10 has the VM22 carb upgrade (upgrade may be wishful thinking). PO installed the carb.

Problem: when idling it seems to run pretty well, but it will, sooner or later, just quit running and it seems like it is running out of gas. Anyone else have this problem? I've adjusted the idle jet on the bottom of the carb - it's about 1.25 turns out from being seated and that would not be considered a lean setting. The main metering rod is on the 2nd notch from the top, which means it's on the lean side of life (we're at 4,600 feet elevation).

Any ideas greatly appreciated.
Larue

[dirtbkr188]

If THIS is the VM22 carb you have, it is the Mikuni-clone carb, and the 'idle jet" you refer to is actually the fuel screw for the pilot jet system. Turning that fuel screw OUT richens the mixture for the idle to 1/4-throttle range.
Did you check the spark plug after it dies, to see if possibly it is loading up due extended idling, and maybe still a tad rich for your altitude?

[rideoutadv]

Originally Posted by laruetou2

I'm new to Chinese bikes and new to this forum. Just bot a BD125-10 - it came with many upgrades. No operator manual (which sucks). No parts manual (which sucks).

Was fooling around with it and put my thumb on the round seal or panel (about 5/8" circular) on the aft side of the master cylinder reservoir. It broke and fluid began dripping out. Bad design, but who am I to advise Honda or the clone makers.

Questions:
1. Do I have to pay for an operator's manual. I'm generally used to finding manuals (all kinds) online with no charge for download.
2. Same with parts manual.
3. Can I repair this master cylinder by replacing the plastic panel or do I need to buy a new master cylinder. Where do I get the panel or the new master cylinder? Is there a spec?

Thanks to all in advance,
Larue

I've successfully reached out to venom powersports for a copy of both the owners and dealers manual, they handed it over to me for free w/o question.