I killed the master cylinder

laruetou2 · 08-31-2024, 12:52 PM

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 · 08-31-2024, 02:04 PM

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

laruetou2 · 09-02-2024, 01:06 AM

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 · Yesterday, 09:11 PM

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.

08-31-2024, 12:52 PM	#1
laruetou2 Join Date: Aug 2024 Posts: 4	I killed the master cylinder 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
	0

08-31-2024, 02:04 PM	#2
dirtbkr188 Join Date: Aug 2009 Posts: 566	Click *HERE* and scroll down to find one that matches your brake lever length
	0

09-02-2024, 01:06 AM	#3
laruetou2 Join Date: Aug 2024 Posts: 4	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
	0

Yesterday, 09:11 PM	#4
laruetou2 Join Date: Aug 2024 Posts: 4	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.
	0