Clinician
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Post by steven on Jul 20, 2021 6:40:53 GMT -6
Did you drain and clean the carburetor?
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Clinician
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Post by steven on Mar 15, 2021 0:49:44 GMT -6
Have you checked the belt and variator area- 1st
2nd- may need valve adjustment
3rd- your carb may be fouled up
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Clinician
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Post by steven on Jul 2, 2015 12:55:18 GMT -6
BTW, it is probably just as well that that particular BBK does not fit.
I want to say that I hate to post this, but I will, because I read a post yesterday about the exact same problem.
I installed that kit. As you know, that is the absolute cheapest price you will find on ebay for a BBK. When you add in all the accessories, that price seems too good to be true. Here is the deal.
I installed that kit. First day, it ran great. Second day, it ran a little worse. 3rd day, it was putting. I ordered a new cylinder and piston from ScootersToGo. The cylinder cost as much as that whole kit. It ran a little better. So, I bought an expensive cylinder head, installed it, and it ran perfect. Is still running perfect 6 mos later. I examined the cylinder, and head on that cheap kit. It has little holes that go all the way through to the cylinder. The head has holes that go all the way through to the combustion chamber. These are casting holes, from cutting corners for cost. It ran fine for the first day because of the assembly lube I used, the lube sealed it temporarily.
You would have had the same problem. Nobody can sell those things that cheap. His stuff is crap.
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Clinician
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Post by steven on Jul 2, 2015 12:33:02 GMT -6
I wouldn't go much smaller. You have it going right. A little too much fuel is good. Too little fuel is bad. When you are running lean(too little fuel), the temperatures start going up and up. Heat is bad. Keep it with as big of a main jet as it will take, without losing performance.
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Clinician
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Post by steven on Jul 2, 2015 12:22:35 GMT -6
Order a new belt, first of all. If you have 10" wheels, you order the belt for the SHORT case 139QMB. If you have 12" wheels, you order a belt for the LONG case.
Take the cover off of your CVT. You probably broke something off of the kick start assembly, and it caught in the belt, and broke it. Take everything to do with the kick start OFF. Check that your clutch, and variator are not damaged. Hopefully, they are not. Spin the clutch bell, and make sure it spins the tire freely, without any grinding noises. Take the variator apart, and examine it, as with the clutch. If all is well, leave the kick start crap OFF, put on the new belt, put the case cover back on, and have fun riding.
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Clinician
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Post by steven on Jul 2, 2015 12:15:29 GMT -6
The solution would be to replace the crankshaft.
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Post by steven on Jul 2, 2015 12:14:59 GMT -6
That sounds like it could be a rod knock, to me. I hate to say that. It's hard to tell from the vid. From the video, it's louder over there by the flywheel, which is on the crankshaft. A bearing probably went out, and the rod is hitting something.
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Post by steven on Jul 2, 2015 12:04:35 GMT -6
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Post by steven on Jun 29, 2015 13:57:21 GMT -6
Most folks believe that the Fuel/Air mixture screw is only for idle but the Pilot Jet passage is always having gas sucked out of it along with the main jet. There is no CUT OFF from the pilot jet it is an open passage and the screw if its a CV CARB cuts off SOME of the fuel passage when turned clockwise having the screw tip go more into the passage. As a matter of fact if you look by the butterfly and open it a little you will see about 4 tiny fuel outlets, the back outlets are ALWAYS open those the screw does nothing to them because the passage for those outlets is BEFORE the fuel Ratio Screw. The Fuel Ratio screw controls only the front outlets not the ones further back. So contrary to what most folks believe sorry to say but they are wrong. Here is a chart of when things get going on a carb. Alleyoop  I believe that chart is over-stating the impact the air/fuel screw has on the performance at WOT. I just screwed mine in all the way, and took it on a ride. Then backed it completely out, to where it was removed, and took it on a ride. It obviously made a difference at idle, but if there was a difference in performance under throttle, it was not noticeable. No difference in top speed. Maybe mine is a rare case. |
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Post by steven on Jun 29, 2015 13:47:59 GMT -6
Without seeing it, it is one of 2 things: Either you over filled the oil, and blew out your oil seals, which would be the case if it is coming out of your fan area. Or, you have a cracked head, or a leaky head gasket. I think you blew your oil seals.
The seals are behind the fan, flywheel, and stator. You have to take the flywheel and stator off. Your stator, which is your electrical generator, is surely coated in oil. Your bike is probably going to lose spark here pretty quick.
The seals are what seals around that crank shaft, that spins the fan, and the flywheel.
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Post by steven on Jun 28, 2015 15:39:00 GMT -6
That kit is 50mm. I bought the exact same one, from the same guy. You have a small aperture in your case. You are probably going to have to try the 47mm. Your engine is an anomoly engine. You may have to go 44mm.
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Post by steven on Jun 28, 2015 15:33:46 GMT -6
Alleyoop, I am almost positive that, on a 50cc carb, the air/fuel mixture screw is only for the IDLE. That screw makes no difference once you are on the throttle.
As for the OP, I would bet that your new carb came with a jet upgrade. A bunch of the new "performance" carbs come with an 85 main jet in them. I would pull the 4 hole breather plug out of your air box. See if that helps. You are going to need more air, or a smaller main jet.
The second guy sounds like he is running lean. I would try the 80, or 85 main jet. Both of you are dealing with a main jet issue.
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No spark
by: steven - Jun 27, 2015 12:46:16 GMT -6
Post by steven on Jun 27, 2015 12:46:16 GMT -6
I guess if the CDI is not sending a pulse to the coil, then that's how you know your pickup coil is not working. I would go ahead and replace the entire stator. You are going to need a flywheel puller. Here is a link: www.nycscooterparts.com/#!electrical--under-both-50-150cc/c1svg |
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Fuel leak
by: steven - Jun 27, 2015 12:40:04 GMT -6
Post by steven on Jun 27, 2015 12:40:04 GMT -6
There is only 1 hose that comes out of the gas tank. Well, there are some vent hoses, but they are on the top, and unless you are riding your scooter upside down, which is another issue, all the gas wouldn't be leaking out of them.
The fuel line runs from the bottom of your gas tank to the carburetor. Just follow the fuel line from the carb(you will find the fuel filter along the way), and you will find where the fuel is leaking out.
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No spark
by: steven - Jun 27, 2015 7:57:11 GMT -6
Post by steven on Jun 27, 2015 7:57:11 GMT -6
Alleyoop, is there another way to test the pickup coil on a DC system, if your multimeter will not pick up the voltage pulses coming off of the pickup coil? I have 2 multimeters, and neither one will read my pickup coil, but it damn sure works, because my scoot runs. I have an AC system, so I can measure the ignition coil on the stator. He doesn't have that luxury.
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