|
|
Post by scooternub on May 11, 2015 5:43:18 GMT -5
Just bought this scooter. Comes with a 49cc motor.
I cannot find much info on this model scooter on the web.
I was looking to derestrict it.
Does anyone have any info on this model scooter?
Does it come with a variator spacer?
Is there an exhaust restricter?
Carb restricter?
I had the cvt cover off, looked for a spacer, from what I could tell, it didn't have a spacer. SHould I take the variator off, to see if a washer falls out? SHall I be very careful by holding the variator together with my hands as I slide it off so the rollers don't fall out?
The gas gauge is broke, by any chance does anyone know how big the fuel tank is on this model scooter?
Top speeds:
Uphill: 25MPH
In the wind: 35MPH
Going with the wind: 40MPH
Downhill: 35-40MPH.
|
|
|
|
Post by scooternub on May 11, 2015 8:25:53 GMT -5
As what I suspected. There is no variator washer.   |
|
|
|
Post by niz76 on May 11, 2015 8:28:41 GMT -5
WELCOME!!
From the speeds you posted it sounds like it may not be restricted at all. Pretty typical speeds for a stock 139qmb...
|
|
|
|
Post by 90GTVert on May 11, 2015 9:15:28 GMT -5
 I agree with Niz. What you listed are very typical speeds for a stock 49cc four-stroke. Pretty much the same as mine. You've got a 139QMB (also called GY6 50) so if you are searching for drivetrain related parts and info use the engine code instead of the scooter model number. The gas tank on a "sunny" style scoot should be just over a gallon. I've seen it quoted from about 1.1 to 1.3 gallons. |
|
|
|
Post by scooternub on May 11, 2015 9:42:21 GMT -5
WELCOME!! From the speeds you posted it sounds like it may not be restricted at all. Pretty typical speeds for a stock 139qmb... I agree with Niz. What you listed are very typical speeds for a stock 49cc four-stroke. Pretty much the same as mine. You've got a 139QMB (also called GY6 50) so if you are searching for drivetrain related parts and info use the engine code instead of the scooter model number. The gas tank on a "sunny" style scoot should be just over a gallon. I've seen it quoted from about 1.1 to 1.3 gallons. Wow, fantastic start. Thanks for the warm welcoming, guys. Thanks for the great info on the motor, fuel capacity and it being unrestricted. I have a few questions on mind to ask. What is this thing coming off the muffler?  and Can I use a better CDI unit? If I have any further questions regarding the motor & parts, may I continue it here in this thread or create a new thread? |
|
|
|
Post by Elektrey on May 11, 2015 11:02:40 GMT -5
thats something to do with emissions, believe its called a PAIR unit or something or other.
you CAN use a better CDI unit but whether or not it actually improves anything is a wild card, it may actually make it run worse too.
You could keep asking questions here I don't see why not.
|
|
|
|
Post by scooternub on May 11, 2015 11:10:19 GMT -5
thats something to do with emissions, believe its called a PAIR unit or something or other. you CAN use a better CDI unit but whether or not it actually improves anything is a wild card, it may actually make it run worse too. You could keep asking questions here I don't see why not. Ok, I'll leave the PAIR unit alone. May I ask why CDI unit change would make things worse? On the jets for this motor are listed as #85 #88 & #95. What are the differences between the three? Also, if I upgraded the jets, will fuel/air mixture have to be readjusted? And! I see for rollers there are 4g 5g and 6g. What are the differences between the three? Btw the motor has 2.5k miles on it. |
|
|
|
Post by Elektrey on May 11, 2015 11:19:41 GMT -5
a new CDI Unit could advance, retard, or have the same ignition timing as the old one. advancing a little might help, but it could also retard it. pretty much there isn't a given consensus on how effective it is. I wouldn't expect much performance boost at all from it anyways.
the jets are for the carb and where do you see three listed? a bigger jet will increase the amount of fuel getting to the engine per part of air. You should have one of those 3 installed in the carb.
Changing the jets IS how you change the fuel/air mixture so I wouldn't mess with it.
Also not sure where you are getting 3 different roller weights from. heavier roller weights will increase the RPM your at when you WOT and lighter roller weights will decrease the RPM you get when you WOT. People figure out at what RPMs there engine makes power, and tune the weights accordingly.
|
|
|
|
Post by scooternub on May 11, 2015 11:36:57 GMT -5
a new CDI Unit could advance, retard, or have the same ignition timing as the old one. advancing a little might help, but it could also retard it. pretty much there isn't a given consensus on how effective it is. I wouldn't expect much performance boost at all from it anyways. the jets are for the carb and where do you see three listed? a bigger jet will increase the amount of fuel getting to the engine per part of air. You should have one of those 3 installed in the carb. Changing the jets IS how you change the fuel/air mixture so I wouldn't mess with it. Also not sure where you are getting 3 different roller weights from. heavier roller weights will increase the RPM your at when you WOT and lighter roller weights will decrease the RPM you get when you WOT. People figure out at what RPMs there engine makes power, and tune the weights accordingly. Ok, so leave cdi unit alone. I apologize for not giving the source of showing three items each of the jets and rollers. www.scrappydogscooters.com/139QMB_50cc_Performance.htmlThe jets would come with the air filter. Rollers are at the top of the page. There is a drop down box for each item. From there you may select from under Performance roller polygon sliders 16x13 4g 5g & 6g. For the jets, High performance air filters section, dropbox for #85 #88 & #95. So basically, I should leave everything alone. |
|
|
|
Post by Elektrey on May 11, 2015 11:49:24 GMT -5
a performance air filter will likely not do anything if much so I wouldn't worry about that.
Rollers might help but they go best with a performance variator and on a stock 4 stroke 50cc I don't think would make too much of a difference.
Do you want to increase its performance?
|
|
|
|
Post by niz76 on May 11, 2015 11:57:32 GMT -5
Haha You probably should leave everything alone, but that's no fun!
Here's a video from 90GTVert that may shed some light on the CDI questions. Basically, the performance CDI's usually have advanced timing which can possibly make for harder starting. He shows in the vid how to advance the timing (free mod!) yourself so the scoot won't be hard to start... If you haven't watched these Tao Tao vids you should!
You can play around with CVT tuning by changing roller weights in your variator and see how they affect your scoot. Your scoot may already have a very good weight in it already, but you'll never know if it can be better until you start playing with them. Lighter roller weights tend to Raise RPM's- sometimes giving a faster take-off. Heavier roller weights do the opposite....
If you're looking for more speed and power consider a 70cc Big Bore Kit. After installing a BBK, then you'll find you need to re-jet the carb and also re-tune the CVT. You may find some minor advantages by playing with the tune of a stock scooter, but adding a Big Bore kit is when things start to get fun!
|
|
|
|
Post by scooternub on May 11, 2015 13:49:38 GMT -5
Ok onto the next project.
How often do CDI's go out? Rare?
I have an identical scooter that does not run. As far as I got with it is no spark even with a good core. What I have done was, tested spark at the plug, pulled the core out of the running bike and put into the non running bike. No spark.
Does this lead to the CDI unit going out? Or the fly wheel parts?
|
|
|
|
Post by 90GTVert on May 13, 2015 5:48:45 GMT -5
I check for voltage out of the 2 wires from the stator that are individual, usually black/red and blue/white. Disconnect them, hook a multimeter to one wire and the other multimeter probe to ground, crank the engine over. One should show roughly 0.5VAC and the other should show 50V or more. If you don't get the 0.5V reading you can try checking the gap between the reluctor (raised bit of flywheel) and the pickup. Something like 0.010" to 0.030" (credit card thickness) should work. If you can't get proper readings it's prob the stator. If you do get proper readings you can move on to the coil, CDI, wiring, or kill switches. I'm guessing you meant to say you swapped the coil, not the core? If so that should be eliminated. The CDI is an easy swap in test so you can check that quickly. If you still get nothing then you may have wires disconnected somewhere or a kill switch may be malfunctioning. Check the black and white wire at the CDI for ground. It should not be grounded when kill and ignition switches are in the run position. If it is, check your switches to see which is bad.
|
|
|
|
Post by scooternub on May 14, 2015 7:31:13 GMT -5
I check for voltage out of the 2 wires from the stator that are individual, usually black/red and blue/white. Disconnect them, hook a multimeter to one wire and the other multimeter probe to ground, crank the engine over. One should show roughly 0.5VAC and the other should show 50V or more. If you don't get the 0.5V reading you can try checking the gap between the reluctor (raised bit of flywheel) and the pickup. Something like 0.010" to 0.030" (credit card thickness) should work. If you can't get proper readings it's prob the stator. If you do get proper readings you can move on to the coil, CDI, wiring, or kill switches. I'm guessing you meant to say you swapped the coil, not the core? If so that should be eliminated. The CDI is an easy swap in test so you can check that quickly. If you still get nothing then you may have wires disconnected somewhere or a kill switch may be malfunctioning. Check the black and white wire at the CDI for ground. It should not be grounded when kill and ignition switches are in the run position. If it is, check your switches to see which is bad. Thanks a bunch for this informative information, in which I will probably use as if a new cdi fails with redone plugs I can somewhat troubleshoot the bike with this knowledge. Also if you haven't seen the post, I found the problem. 49ccscoot.proboards.com/post/175198/thread |
|
