New Rider
Currently Offline
Posts: 21 
Likes: 4
Joined: Jul 18, 2015 1:02:00 GMT -5
|
Post by truebluethecat on Jul 18, 2015 1:14:08 GMT -5
Ok I just bought a 2008 "sunny 50" scooter. Further research showed its a gy6 139qmb. Bought it knowing it wasn't quite working right sure but it sounded to me like it just had bad gas and a dirty carb. So I drained the 3 year old gas. Hosed the carb down and it starts just fine. All sounds good and twist the throttle it sounds great....while its on the center stand that is. Once the back tire hits the ground it won't go. Idles fine but give it gas and it just barely gives a small tug. That's it, didn't matter where I place the air mix screw at that's all I get. Going to pull the carb off and tear it down and clean it real good. What I'd like to know is this. My first time with a gy6 carb, any thing I should keep an eye for? And any ideas of what else it could be in this situation? Coil maybe?
|
|
|
|
Post by geh3333 on Jul 18, 2015 3:24:53 GMT -5
Ok I just bought a 2008 "sunny 50" scooter. Further research showed its a gy6 139qmb. Bought it knowing it wasn't quite working right sure but it sounded to me like it just had bad gas and a dirty carb. So I drained the 3 year old gas. Hosed the carb down and it starts just fine. All sounds good and twist the throttle it sounds great....while its on the center stand that is. Once the back tire hits the ground it won't go. Idles fine but give it gas and it just barely gives a small tug. That's it, didn't matter where I place the air mix screw at that's all I get. Going to pull the carb off and tear it down and clean it real good. What I'd like to know is this. My first time with a gy6 carb, any thing I should keep an eye for? And any ideas of what else it could be in this situation? Coil maybe? How's it going? How many miles ? The problem could be a number of things. From the carb to the CVT to the valves needing adjusted. Does it bog down when you give it gas " while sitting on her" . |
|
|
|
Post by lain on Jul 18, 2015 8:33:01 GMT -5
I would check the belt. It sat for 3 years, might be due to previous owner storing it when something went wrong, in this case it sounds like a transmission issue. Check the variator as well.
|
|
|
|
Post by ghcoe on Jul 18, 2015 12:08:29 GMT -5
Sounds like the clutch is sticking or faulty since it gives a slight tug when throttled up. Sounds like the clutch is trying to engage by the slight tug sensation description, but is not able to fully grab.
|
|
|
|
Post by scooter on Jul 18, 2015 12:38:04 GMT -5
Ok I just bought a 2008 "sunny 50" scooter. Further research showed its a gy6 139qmb. Bought it knowing it wasn't quite working right sure but it sounded to me like it just had bad gas and a dirty carb. So I drained the 3 year old gas. Hosed the carb down and it starts just fine. All sounds good and twist the throttle it sounds great....while its on the center stand that is. Once the back tire hits the ground it won't go. Idles fine but give it gas and it just barely gives a small tug. That's it, didn't matter where I place the air mix screw at that's all I get. Going to pull the carb off and tear it down and clean it real good. What I'd like to know is this. My first time with a gy6 carb, any thing I should keep an eye for? And any ideas of what else it could be in this situation? Coil maybe? It tugs and dies, or it tugs and the engine keeps zipping along while the wheel doesn't move? |
|
New Rider
Currently Offline
Posts: 21
Likes: 4
Joined: Jul 18, 2015 1:02:00 GMT -5
|
Post by truebluethecat on Jul 18, 2015 18:00:11 GMT -5
Thank you all for your replys. I hadn't even thought to check the transmission good call. Pulled it open and saw what looks to be a brand new belt. Spun it by hand a few times and heard clinking. So pulled open the front variator to find the sliders not sitting right. It appeared the last owner thought they should be standing up instead of rolling on their sides. Any ways she's going now if not as fast as I'd like. Seems to be leveling out at 25 mph. That normal? My old minarelli 2t got up to 30 no prob 35 a few seconds later and on flat long stretch got her up to 40. No mods.got this scoot to be a commuter but cant do that if it only tops at 25. Spent 2 hours adjusting the air flow mix never saw much of a difference till it was nearly screwed all the way in and not a big one at that
|
|
New Rider
Currently Offline
Posts: 21
Likes: 4
Joined: Jul 18, 2015 1:02:00 GMT -5
|
Post by truebluethecat on Jul 18, 2015 18:06:35 GMT -5
Oh and BTW that's 25mph via gps. But the speedo is saying the same so guess I got the rare chineese working one. Haha
|
|
|
|
Post by lain on Jul 18, 2015 18:18:52 GMT -5
Try cutting the wire that goes to the transmission case, it will remove the rev limiter on stock CDIs. That's how a lot of 50cc 4 strokes are though, but you could try some different variator weights to tune the transmission as well.
|
|
|
|
Post by geh3333 on Jul 18, 2015 18:22:00 GMT -5
Thank you all for your replys. I hadn't even thought to check the transmission good call. Pulled it open and saw what looks to be a brand new belt. Spun it by hand a few times and heard clinking. So pulled open the front variator to find the sliders not sitting right. It appeared the last owner thought they should be standing up instead of rolling on their sides. Any ways she's going now if not as fast as I'd like. Seems to be leveling out at 25 mph. That normal? My old minarelli 2t got up to 30 no prob 35 a few seconds later and on flat long stretch got her up to 40. No mods.got this scoot to be a commuter but cant do that if it only tops at 25. Spent 2 hours adjusting the air flow mix never saw much of a difference till it was nearly screwed all the way in and not a big one at that Were all the sliders the same way , or were some flip and others OK ? That's the issue I have with sliders . they can flip out of place on you . I've had it happen many times when I was trying them out. I'mnot sure if it was my junk koso variator or not . let's say for instance you have an issue with the CVT as your slowing down . let's say the clutch pulley sticks open. This means the variator will begin to open back up creating a lot of slack in the belt , which will then cause the variator to become very loose , allowing the back plate to seperate very easy causing an opportunity for the sliders to easily flip . with rollers you do not have this issue. |
|
New Rider
Currently Offline
Posts: 21
Likes: 4
Joined: Jul 18, 2015 1:02:00 GMT -5
|
Post by truebluethecat on Jul 18, 2015 20:31:08 GMT -5
@lian. I'll will investigate that. Was wondering about limiters geh3333. These where round roller weights and they all looked the same. But I know what your talking about happened twice on my old scoot. Ha-ha "stuff" happens |
|
|
|
Post by tvnacman on Jul 19, 2015 7:31:24 GMT -5
Try cutting the wire that goes to the transmission case, it will remove the rev limiter on stock CDIs. That's how a lot of 50cc 4 strokes are though, but you could try some different variator weights to tune the transmission as well. Do Not Cut The Engine Ground wire, You Will Burn Your Stator Ground The First Time You Hit The Electric start. I would remove the clutch and overhaul it. Be sure the variator is not binding either. If you want to change the timing or Rev limiter, go with a different cdi and coil. John |
|
|
|
Post by lain on Jul 19, 2015 7:42:17 GMT -5
Try cutting the wire that goes to the transmission case, it will remove the rev limiter on stock CDIs. That's how a lot of 50cc 4 strokes are though, but you could try some different variator weights to tune the transmission as well. Do Not Cut The Engine Ground wire, You Will Burn Your Stator Ground The First Time You Hit The Electric start. I would remove the clutch and overhaul it. Be sure the variator is not binding either. If you want to change the timing or Rev limiter, go with a different cdi and coil. John No one said anything about cutting engine ground wires, read before you quote. |
|
|
|
Post by tvnacman on Jul 19, 2015 7:45:38 GMT -5
Do Not Cut The Engine Ground wire, You Will Burn Your Stator Ground The First Time You Hit The Electric start. I would remove the clutch and overhaul it. Be sure the variator is not binding either. If you want to change the timing or Rev limiter, go with a different cdi and coil. John No one said anything about cutting engine ground wires, read before you quote. There Are Two Wires That Attach To The engine one is the stator harness and the other is the engine and there can be more than one engine ground. If you know of others please show us/me. John |
|
|
|
Post by lain on Jul 19, 2015 8:00:24 GMT -5
No one said anything about cutting engine ground wires, read before you quote. There Are Two Wires That Attach To The engine one is the stator harness and the other is the engine and there can be more than one engine ground. If you know of others please show us/me. John The answer is literally right in front of you, please read what you quoted so you will understand... I highly doubt you forgot there is also a wire that goes to the transmission, maybe you did, I don't know. That's why I said read before you quote, because you misread what I said. It's really not that serious, but when you do that you make people get confused and can lead someone away from useful information. |
|
|
|
Post by tvnacman on Jul 19, 2015 12:16:28 GMT -5
There Are Two Wires That Attach To The engine one is the stator harness and the other is the engine and there can be more than one engine ground. If you know of others please show us/me. John The answer is literally right in front of you, please read what you quoted so you will understand... I highly doubt you forgot there is also a wire that goes to the transmission, maybe you did, I don't know. That's why I said read before you quote, because you misread what I said. It's really not that serious, but when you do that you make people get confused and can lead someone away from useful information. OK I have worked on many 50 and 150cc engines. I pull them out to rebuild them. There is a vent from the gear box. I have not seen a wire. Again if I'm mistaken please show it to me/us. Is this in any diagrams? John |
|
