SUNL scooter, questionable condition

BrianW · 08-20-2019, 08:31 PM

A neighbor just gave me a 50cc SUNL scooter that was in his barn when he bought his property. It’s a 2006 model with 218 miles but has been in this barn for at least 8 years and who knows if it ran when parked there. No title, no key, no gas cap, etc. I’m wondering what my first steps should be, particularly how to bypass the ignition switch. Primarily, (if not blown up) I hope to teach my wife to ride on it and have it as a “farm bike”.

Engine has compression. Definitely going to drain tank and change oil/ spark plug. Any feedback is appreciated

BrianW · 08-20-2019, 08:36 PM

A photo for reference, I believe it is the basic gy6 engine

humanbeing · 08-21-2019, 05:38 AM

Typical color code: http://chinariders.net/showpost.php?...3&postcount=11
Typical 50cc GY6

Divides electrics into different groups is easier for layman's mind.
Good old 125cc Kymco GY6 (ie. the real deal) in above format

BrianW · 08-21-2019, 12:35 PM

Thanks Humanbeing, that is a very helpful schematic. Following it, it looks as though everything electrical on this bike is satisfactory so far.

Since I’ve not much experience with the gy6, I’m not sure what this black cylinder is for. This cylinder and the throttle handle/cable seem to be the only disconnected pieces at this point.

tortoise · 08-21-2019, 01:58 PM

Quote:

Originally Posted by BrianW

not sure what this black cylinder is for

Quote:

Originally Posted by BrianW

how to bypass the ignition switch

Remove kill switch pin from CDI connector.

wheelbender6 · 08-21-2019, 02:11 PM

Farm bike is a good use for it. The engines were pretty good but electric problems were common.

BrianW · 08-21-2019, 06:52 PM

So I got the scooter to fire up. It idles surprisingly well and will rev up if done very slowly and carefully but will then die and is difficult to start. Cleaned the jets, bowl, float, changed oil and spark plug. Not sure what else to do next.

The vacuum systems on these are interesting- I have a lot to learn about them still. Also, unfamiliar with the concept of an electronic choke.

tortoise · 08-21-2019, 08:14 PM

Quote:

Originally Posted by BrianW

Not sure what else to do next.

Cut a strip from the side of an aluminum beverage can for a feeler gauge.

BrianW · 08-21-2019, 08:19 PM

Quote:

Originally Posted by tortoise

Cut a strip from the side of an aluminum beverage can for a feeler gauge.

But I’ve been drinking bottles all day!

Thanks for the video- good suggestion!

humanbeing · 08-21-2019, 08:58 PM

Quote:

Originally Posted by tortoise

Cut a strip from the side of an aluminum beverage can for a feeler gauge.

That trick is good enough for GY6 125/150

BUT 50cc needs narrower 0.05mm/ ~0.002" clearence.

BrianW · 08-22-2019, 03:58 PM

Adjusted the valves and they certainly needed it. Top was at .007 and bottom was too tight to measure. Bike still runs rough and behaves pretty much the same. Will idle but does when revved and then is hard to start. Wondering if my effort to clean the carb wasn’t good enough, as it was my first time ever actually cleaning a carb and not just replacing it.

tortoise · 08-22-2019, 05:47 PM

Quote:

Originally Posted by BrianW

Wondering if my effort to clean the carb wasn’t good enough.

Guidelines

BrianW · 08-23-2019, 11:22 PM

Put a new carb on today and the bike idles and revs perfectly now. A new throttle cable, throttle tube, keyed ignition/gas cap/seat lock and everythingis coming together nicely. Need to charge the battery, sort out the electric start wiring, and fix-a-flat the back tire and it will be ready for a quick riding lesson with my wife.

This thing was certainly ridden hard and put away wet for a very long time and still wants to run. These little motors are tough. Thanks again everybody!

BrianW · 08-25-2019, 03:47 PM

Alright, so not smooth sailing yet. First issue is that when the rear brake applied, there is a noise that comes from the rear of the engine that sounds like the noise you get when you try to turn the bike over with elec start when it’s already running. I don’t know if this is related to the stock brake system or if it has been tampered with in the past. Second issue is that after getting the rear tire to re-seat on the rim, the whole this is lopsided and bouncy when spinning on the center stand. Maybe a bent rim but I’m fearful that the rear drive shaft may be bent.

cbrfxr67 · 08-26-2019, 05:11 PM

cool reading your progres!

08-20-2019, 08:31 PM	#1
BrianW Join Date: Feb 2008 Location: Wheeling, WV native currently living In Natchitoches, LA Posts: 297	SUNL scooter, questionable condition A neighbor just gave me a 50cc SUNL scooter that was in his barn when he bought his property. It’s a 2006 model with 218 miles but has been in this barn for at least 8 years and who knows if it ran when parked there. No title, no key, no gas cap, etc. I’m wondering what my first steps should be, particularly how to bypass the ignition switch. Primarily, (if not blown up) I hope to teach my wife to ride on it and have it as a “farm bike”. Engine has compression. Definitely going to drain tank and change oil/ spark plug. Any feedback is appreciated
	0

08-21-2019, 05:38 AM	#3
humanbeing Join Date: Mar 2008 Posts: 2,436	Typical color code: http://chinariders.net/showpost.php?...3&postcount=11 Typical 50cc GY6 Divides electrics into different groups is easier for layman's mind. Good old 125cc Kymco GY6 (ie. the real deal) in above format __________________
	1

08-21-2019, 02:11 PM	#6
wheelbender6 Join Date: May 2015 Location: Houston area Posts: 1,902	Farm bike is a good use for it. The engines were pretty good but electric problems were common. __________________ "Its not WHAT you ride; its THAT you ride"
	1

08-26-2019, 05:11 PM	#15
cbrfxr67 Join Date: Jun 2018 Location: HOuston Posts: 357	cool reading your progres! __________________ BD125-15
	0

08-21-2019, 06:52 PM	#7
BrianW Join Date: Feb 2008 Location: Wheeling, WV native currently living In Natchitoches, LA Posts: 297	So I got the scooter to fire up. It idles surprisingly well and will rev up if done very slowly and carefully but will then die and is difficult to start. Cleaned the jets, bowl, float, changed oil and spark plug. Not sure what else to do next. The vacuum systems on these are interesting- I have a lot to learn about them still. Also, unfamiliar with the concept of an electronic choke.
	0

08-22-2019, 03:58 PM	#11
BrianW Join Date: Feb 2008 Location: Wheeling, WV native currently living In Natchitoches, LA Posts: 297	Adjusted the valves and they certainly needed it. Top was at .007 and bottom was too tight to measure. Bike still runs rough and behaves pretty much the same. Will idle but does when revved and then is hard to start. Wondering if my effort to clean the carb wasn’t good enough, as it was my first time ever actually cleaning a carb and not just replacing it.
	0

08-23-2019, 11:22 PM	#13
BrianW Join Date: Feb 2008 Location: Wheeling, WV native currently living In Natchitoches, LA Posts: 297	Put a new carb on today and the bike idles and revs perfectly now. A new throttle cable, throttle tube, keyed ignition/gas cap/seat lock and everythingis coming together nicely. Need to charge the battery, sort out the electric start wiring, and fix-a-flat the back tire and it will be ready for a quick riding lesson with my wife. This thing was certainly ridden hard and put away wet for a very long time and still wants to run. These little motors are tough. Thanks again everybody!
	0

08-25-2019, 03:47 PM	#14
BrianW Join Date: Feb 2008 Location: Wheeling, WV native currently living In Natchitoches, LA Posts: 297	Alright, so not smooth sailing yet. First issue is that when the rear brake applied, there is a noise that comes from the rear of the engine that sounds like the noise you get when you try to turn the bike over with elec start when it’s already running. I don’t know if this is related to the stock brake system or if it has been tampered with in the past. Second issue is that after getting the rear tire to re-seat on the rim, the whole this is lopsided and bouncy when spinning on the center stand. Maybe a bent rim but I’m fearful that the rear drive shaft may be bent.
	0