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Post by gift on Mar 8, 2015 15:06:13 GMT -5
I also just take a quick look at the carb. It is stock seal carb and now I am thinking if it is worth unsealing it myself or i should just get Keihin carb for $30 (found one on ebay). To unseal the stock one, I will need to get screw extractor and some more replacement screws and lock washers which might end up be close to $30.
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Post by onewheeldrive on Mar 8, 2015 20:29:45 GMT -5
Hmmm. Well, it looks to be running rich, to say the least. I wonder what the main jet in the carb is? How many miles on the engine?
Since you have the piston off the rod, I'd check for play in it--- a bit (1 or so mm) of left/right sideplay is ok and pretty normal, but up/down play where the rod bearing is (you cant see it) is not good. I'd at least rule that out before putting back together.
Did the people you bought it off of mention any symptoms at all, other than it just "not running right"?
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Post by gift on Mar 8, 2015 21:57:21 GMT -5
Hmmm. Well, it looks to be running rich, to say the least. I wonder what the main jet in the carb is? How many miles on the engine? Since you have the piston off the rod, I'd check for play in it--- a bit (1 or so mm) of left/right sideplay is ok and pretty normal, but up/down play where the rod bearing is (you cant see it) is not good. I'd at least rule that out before putting back together. Did the people you bought it off of mention any symptoms at all, other than it just "not running right"? I am trying to unseal the carb to see the jets inside. I will let you know as soon as I can get in it. It has 1757 km on odometer which is about 1000 miles. The previous owner did not tell me anything other than not running right. I will call them and ask for more detail tomorrow. Hopefully they could tell me more about it. |
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Post by JoeyBee on Mar 8, 2015 22:09:55 GMT -5
If I want to replace the engine, it would cost me about $250-$300. Otherwise he would give me $175 for the moped because the frame is still good. What kind of budget do you have for this project? Do you want to just get it running with a few problems, or a reliable working order? |
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Post by gift on Mar 8, 2015 22:30:50 GMT -5
If I want to replace the engine, it would cost me about $250-$300. Otherwise he would give me $175 for the moped because the frame is still good. What kind of budget do you have for this project? Do you want to just get it running with a few problems, or a reliable working order? I would like to have it in reliable working order but I do not have $300 to spend on it right now. I already spent $400 on it if there is a way to minimize my cost I would like to go that way. |
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Post by JoeyBee on Mar 8, 2015 23:14:14 GMT -5
Okay. The first thing noticeable is that the engine was running VERY rich. That is why your spark plug and piston are black as night. Once the scooter is up and running the carb will need to be tuned. To do that access is needed to both the fuel mixture screw and main jet. You may be able to get away with just the fuel mixture screw, but both are preferable. That can be done by unrestricting it or purchasing a replacement online. Carb tuning guides are available in the tech library.
Next will be servicing the motor. Replace all fluids for the engine. Not sure if it is 2 or 4 stroke, but you need to be sure you have good lubricantion. Next would be the decision of if your going to reuse the piston and cylinder wall or replace it. If you go with a stock 49cc replacement set, the cost is not bad. A replacement piston and cylinder wall would be preferable since there was that huge scuff mark on the top of the piston. Once the engine is put back together next would be checking the valve lash. Intake and ex take valves for a 49cc should be .003 inches.
After the engine would be dumping all old fuel and starting fresh. With the tank empty check all fuel line connections and replace the fuel filter. They are very cheap.
Next remove all those emission controls on the scooter. They may also be partly to blame for the poor condition of the engine. Instead of allowing the engine and gas tank vent to the atmosphere, they recirculate dirty fumes back into the cylinder to "burn". That burning is very inefficient and ruins the air/fuel ratio. Removing those allows only clean air and fuel to be burned.
Those steps should get you back to a fairly decent working order.
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Post by JerryScript on Mar 8, 2015 23:33:36 GMT -5
I agree, it's been running a bit rich, but that is not a huge issue. It's better to be too rich than too lean on these engines. I would agree you should start by removing the tangle of emissions related hosing. Here's a thread that will help you identify what emissions parts you have. Let us know which you have, and we can tell you how to remove and plug them. itistheride.boards.net/thread/4902/emissions-scootWhat concerns me is the coloring down around the lower rings of the piston. When it's put together, take the spark plug out and put your finger over the hole, then press the starter. It should blow your finger off the hole. If it doesn't, or just gives a "phhht" without really pushing your finger off, then we may have a compression issue. |
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Post by gift on Mar 8, 2015 23:37:55 GMT -5
Okay. The first thing noticeable is that the engine was running VERY rich. That is why your spark plug and piston are black as night. Once the scooter is up and running the carb will need to be tuned. To do that access is needed to both the fuel mixture screw and main jet. You may be able to get away with just the fuel mixture screw, but both are preferable. That can be done by unrestricting it or purchasing a replacement online. Carb tuning guides are available in the tech library. Next will be servicing the motor. Replace all fluids for the engine. Not sure if it is 2 or 4 stroke, but you need to be sure you have good lubricantion. Next would be the decision of if your going to reuse the position and cylinder wall or replace it. If you go with a stock 49cc replacement set, the cost is not bad. A replacement piston and cylinder wall would be preferable since there was that huge scuff mark on the top of the piston. Once the engine is put back together next would be checking the valve lash. Intake and ex take valves for a 49cc should be .003 inches. After the engine would be dumping all old fuel and starting fresh. With the tank empty check all fuel line connections and replace the fuel filter. They are very cheap. Next remove all those emission controls on the scooter. They may also be partly to blame for the poor condition of the engine. Instead of allowing the engine and gas tank vent to the atmosphere, they recirculate dirty fumes back into the cylinder to "burn". That burning is very inefficient and ruins the air/fuel ratio. Removing those allows only clean air and fuel to be burned. Those steps should get you back to a fairly decent working order. Thank you so much. I will follow all the steps you gave here. Now I really wonder what the previous owner has done to the scoot. From what I have read, these TaoTao scoots are normally set lean from the factory. Thanks again...hopefully, I will get to ride it soon. |
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Post by gift on Mar 8, 2015 23:45:42 GMT -5
I agree, it's been running a bit rich, but that is not a huge issue. It's better to be too rich than too lean on these engines. I would agree you should start by removing the tangle of emissions related hosing. Here's a thread that will help you identify what emissions parts you have. Let us know which you have, and we can tell you how to remove and plug them. itistheride.boards.net/thread/4902/emissions-scootWhat concerns me is the coloring down around the lower rings of the piston. When it's put together, take the spark plug out and put your finger over the hole, then press the starter. It should blow your finger off the hole. If it doesn't, or just gives a "phhht" without really pushing your finger off, then we may have a compression issue. Thanks JerryScript for the thread. I am just looking up on that. Is it possible to have more than one? I am sure I have the PAIR ( Pulsed Air Injection Reburn ) but I am not sure whether there are others or not. I will check on the compression after I put it back together. |
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Post by JoeyBee on Mar 8, 2015 23:51:32 GMT -5
Typically TaoTao are set to be very lean from the factory to adhere to emission controls. Tuning the card will fix that.
Valve clearance, or lash, is also set very tight from the factory. That's why from the factory the valves are very quiet. Once adjusted properly you will notice a faint ticking. Once the ticking goes away, you'll know the valves need adjusting again.
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Post by JerryScript on Mar 9, 2015 0:30:02 GMT -5
I agree, it's been running a bit rich, but that is not a huge issue. It's better to be too rich than too lean on these engines. I would agree you should start by removing the tangle of emissions related hosing. Here's a thread that will help you identify what emissions parts you have. Let us know which you have, and we can tell you how to remove and plug them. itistheride.boards.net/thread/4902/emissions-scootWhat concerns me is the coloring down around the lower rings of the piston. When it's put together, take the spark plug out and put your finger over the hole, then press the starter. It should blow your finger off the hole. If it doesn't, or just gives a "phhht" without really pushing your finger off, then we may have a compression issue. Thanks JerryScript for the thread. I am just looking up on that. Is it possible to have more than one? I am sure I have the PAIR ( Pulsed Air Injection Reburn ) but I am not sure whether there are others or not. I will check on the compression after I put it back together. Yes, but if you have PAIR, you usually do not have EGR. The PAIR system has a metal tube looping up and down in front of the valve cover. The EGR system has a tube coming out of the exhaust header with a rubber hose attached to it. What is more likely is to have an EVAP with either. The EVAP controls gas vapors from the tank, and gets ruined easily if the scooter is leaned too far in any direction with a full tank. The EVAP system does not affect performance other than sometimes causing a lack of fuel delivery at WOT if it is clogged. If you remove either the PAIR or EGR system, you will have to plug the hole they attach to. The PAIR port just needs a small piece of metal with two holes drilled to match where the tube attached. The EGR needs a plug welded onto it. Once you do remove all those useless hoses, it will be easier to work on the engine with less tangle around it. And once tuned, your scooter should run a bit better without them. |
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Post by geh3333 on Mar 9, 2015 0:41:47 GMT -5
Not sure if anyone mentioned this but , since you removed the piston from the cylinder you should just replace the top end . the rings were seated , but now they will not seat right , or u can have the cylinder honed and get new rings .
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Post by geh3333 on Mar 9, 2015 0:45:24 GMT -5
Not sure if anyone mentioned this but , since you removed the piston from the cylinder you should just replace the top end . the rings were seated , but now they will not seat right , or u can have the cylinder honed and get new rings . Also , was the plug out when you were turning the engine with the fan ? It seemed a little too easy to turn , and it also sounded a little rough . |
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Post by gift on Mar 9, 2015 9:48:16 GMT -5
Not sure if anyone mentioned this but , since you removed the piston from the cylinder you should just replace the top end . the rings were seated , but now they will not seat right , or u can have the cylinder honed and get new rings . Also , was the plug out when you were turning the engine with the fan ? It seemed a little too easy to turn , and it also sounded a little rough . No the spark plug was in there when I turned the fan. |
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Post by geh3333 on Mar 9, 2015 10:23:15 GMT -5
Also , was the plug out when you were turning the engine with the fan ? It seemed a little too easy to turn , and it also sounded a little rough . No the spark plug was in there when I turned the fan. When you spin the engine with the fan , does it get harder to turn at times. Or did it stay that easy ? |
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