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Post by dollartwentyfive on Feb 21, 2017 19:31:56 GMT -5
Would torqueing the bolts more than the specs say to try to get the gaskets to seal be a good idea or a bad idea? I'm just not sure what I've done wrong. I have definitely taken my time and tried to do it right. I was pretty careful with the aluminum. How do I tell if the dowel pins aren't too long? I used the old ones. I have two new ones. Should I have used them? I have a new head gasket that came with the head. I had used head gasket that came in a gasket kit. Should I get some Copper Coat and try to replace the head gasket with the one that came with the head and use copper coat? maybe you have done NOTHING wrong. if the above is true then you must assume some sort of manufacturing defect, either with the dowel pins being too long, or their cavities being too shallow, or the mating surfaces aren't exactly true. i do not recommend overtorquing aluminum. i would give those dowel pins a going over. or, make sure there isn't some kind of contaminant inside the dowel cavities. also, are you sure you got the headbolts back into the holes they came from? i don't see how this would matter, but leave it to the chinese to make it happen though. added to that, are you sure nothing fell into the headbolt holes? if you MUST modify the head, then document why and then return it as a manufacturing defect. i can't overstress that, although aluminum engine blocks aren't pure aluminum, aluminum is very soft. i do not recommend any type of metal scraper be used when removing gasket material, unless you are very, very, very careful. even sandpaper can have very bad consequences. from the above, it seems obvious to use gasket sealers that are easily removed. or maybe none at all, although i have never replaced a gasket without some type of sealer (even just a film of grease) |
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Post by dollartwentyfive on Feb 21, 2017 11:11:56 GMT -5
i can't tell you what is adequate as far as fuel flow goes.
i only know that a 6 inch vertical drop is adequate fuel flow for my 244.
as far as your leaking head/ crankcase, i can only guess that there is some kind of contaminant in the joint, insufficient torque, or you have gouged the metal, which is uber easy with aluminum.
it could also be a manufacturing defect.
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Post by dollartwentyfive on Feb 21, 2017 0:09:18 GMT -5
The next issue is when I turn it over nothing happens with everything together. It doesn't ever fire. When I pulled the air box off it will fire and run briefly if I hold my hand over the air intake on the carb. This indicates to me that the air/fuel ratio isn't correct on the carb. Is my thinking right? When I then put the air box back on and moved the a/f screw to several positions I could never get it to fire. How do I get it to fire with the air box on? my guess would be the slow jet or not enough fuel. your engine should run with, or without an airbox or uni filter. these chinese rides can give you screaming fits in trying to diagnose them, simply because of the shortcuts the chinese make. for example, an iffy ignition switch can drive you crazy trying to figure out why it died or won't start. bad connectors only compound the problem. the first and foremost thing i would do is make sure my electrics was solid. in my case that included that critter called an autochoke. the PDI in this case is definitely worth it. not only do you catch a great many problems, you get to know your ride, and not get freaked out when it does break so, judging from the standpoint that your electrics is good, i would check out the slow jet. it seems you could clean it with a guitar string, i doubt a bread tie would be stiff enough. |
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Post by dollartwentyfive on Feb 19, 2017 17:44:32 GMT -5
I wouldn't even say you have to be "mechanically inclined" when looking into a Chinese scooter (specifically). I'd say "physically able and more than half a brain" (maybe not "more than 1/2 a brain", just some common sense and willingness to learn) that can afford a few new tools here and there. I know there are always exceptions. Some people just can't do certain things and that's understandable, but I believe most people CAN--especially with a little encouragement, which I've seen in the forums many times! Really all you need to do is a little searching (most people today know how-- especially the younger generation) for a repair manual, know how to use a wratchet and a screwdriver, maybe an impact wrench. Almost anything you want to know about Chinese scooters is online. It really isn't hard to find scooter forums either, because probably any issue you search for will show up the first page and from a scooter forum. As a matter of fact, I'd even say if you want to be more "mechanically inclined" then buy a Chinese scooter, because you will have to work on it. It's not rocket science, especially when all the information is right in front of you, and a lot of it is well layed out and organized. It's really more about the person and how far they are willing to go to gain the knowledge that is out there already and put it to use. I've seen quite a few people come to the forums that have "worked on bikes and cars their whole life" stumped by a Chinese scooter. It happens to a lot of people, and there is nothing wrong with it, imo. We all learn together from other people's problems here anyway. I'm sure most of us didn't initially sign up to a scooter forum to "hang out", lol. Sooner or later most people will get stumped (I have many times) but like I said earlier, there is lots of help and info out there. Take away the internet, that's another story. +1 i know exactly what you mean. my 50cc was my first encounter with a scooter, and i was obsessed from the get go. i landed on scootdawg (RIP bro), and i'm hopelessly hooked. i'll never own a "geared" motorcycle, and that isn't disrespect, it's that gears just freak me out. that site helped me a lot, maybe i should say IT taught me everything i knew. here's a bone for ya. |
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Post by dollartwentyfive on Feb 19, 2017 13:05:30 GMT -5
dollartwentyfive. Mine has a vacuum fuel pump. How does low vacuum at high engine speed show up? Limited top speed, not responsive at top speeds?... Did you change yours to electric? manifold vacuum is the highest with a closed throttle (idle). the valve/pump operates the best at idle. as you increase the throttle, the vacuum decreases, your pump/ valve becomes less efficient. by the time you reach WOT, manifold vacuum virtually vanishes, rendering your pump/ valve inoperable IOW, you will idle good, but WOT cannot be sustained (you must constantly open/ close the throttle). i tried an electric pump, but it didn't work well for me, i decided to go with a direct feed with a manual shutoff valve. i had no problems at WOT with this setup. in using the above setup, you must remember that the gas tank outlet must be a minimum of 6 inches ABOVE the carb fuel inlet. |
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Post by dollartwentyfive on Feb 18, 2017 22:30:10 GMT -5
The nipple came from Parts for Scooters and I installed it. I am working on putting the rest of the engine back together. I decided to test the fuel pump and see how it is working. When I removed the fuel line between the fuel pump and the carb and turned it over the fuel is not very strong. I don't know if this is normal or if I have low vacuum or a bad pump. i don't know if the 257 has the pump or the valve, but if it uses vacuum, then you should know that manifold vacuum is very low at high speeds. my 244 had the valve, and it was completely worthless at high speeds. some have used an electric pump and said they had good results. if your gas tank outlet is 6 vertical inches above the carb inlet, then you can use a direct feed, but you will need a manual shutoff valve. NAPA sells a briggs and stratton valve that will work. be aware that forgetting to shut off the fuel can have bad effects. a sticky carb float with an open intake valve, and you can be greeted with an engine full of gas. |
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Post by dollartwentyfive on Feb 18, 2017 22:15:02 GMT -5
why try to remove the old one?
i'm sure if you shopped around that you could find something that fits the new head.
don't forget such places as plumbing supply stores, they just might have what you need.
old dehumidifiers might have the right sized tubing.
if you can't get a press fit, then you will need a little JB weld
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Post by dollartwentyfive on Feb 18, 2017 17:37:59 GMT -5
. . .
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Post by dollartwentyfive on Feb 18, 2017 17:34:18 GMT -5
I added a grounding strap between the frame and the starter motor. Now it turns over good and for a long time. hmmm . . . the starter ground needs to run from the starter to the battery using the shortest length possible (disregarding routing issues). i have no idea how that little green wire ground is handling all that starter current. how many ground wires do you have connected to the negative battery terminal, and what color, size are they? my experience is with the 244, so someone else needs to provide input in this area. i want to make a point here though. my bike has an auto choke connected to the carb, and is run from the stator. it also appears that this auto choke is made for 12vdc, and is interchangeable with the stator model. so, if you get a 12v autochoke, make sure that it operates from 12v, NOT the stator, and vice versa. it took me awhile, but i finally figured out how to get rid of this little critter too. it can't be just removed, it has to remain in place, but rendered non functional in the "no choke" position. it can't be just unplugged, the device itself must be modified. be advised though, i still had to manually choke the engine to get it started sometimes. the design of my airbox allowed me to do that. start the bike with my right hand, while reaching down and blocking the airbox intake with my left. yes, i bypassed both brakes with my rewiring job (not recommended) BTW, sparks can be pretty hard to see in daylight. also, i recommend an iridium spark plug. they aren't cheap, i paid either 8 or 12 bucks for mine, but definitely worth it. |
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Post by dollartwentyfive on Feb 18, 2017 7:46:50 GMT -5
Very good advice Twenty, but I think he's turned a corner with this one.... Aren't Chinese scooters FUN?...LOL! actually my 50cc was fun to own. gave $300 for it, rode the crap out of it for a couple of years. changed the oil a few times, then sold it for $300 bucks when i got my 250. i remember waking up in the middle of the night, and the first thing that came to my mind was riding my 50cc. and off i would go. hardly no problems at all with that bike. the plastics was quality material, electrics likewise this is the reason i can't say all chinese scooters are junk. because that simply isn't true. |
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Post by dollartwentyfive on Feb 17, 2017 20:42:04 GMT -5
I just checked and right now the battery is producing 12.45 volts and the starter has 12.25 volts when the start button is pressed. If there is only a 0.20 volt drop across the wiring through the solenoid and to the battery doesn't that indicate that the connections are good? this small resistance doesn't sound like much, but when you start dumping a lot of amps through it, it will cause a voltage drop that would be enough to keep the starter from turning under load. this is one of the reasons you should purchase the entire cable for your car starter. those aftermarket end clamps will soon get to where they will fail, because of corrosion. how can they not have good connection when the cable is literally clamped in there. but it will, you can count on it so, check your battery circuit connections VISUALLY. remove each one, and remove all the stuff that doesn't belong there, off of the wire AND the screw terminal. you will have 2 for the battery, 2 for the solenoid, and 2 for the starter. also, make sure the start ground is actually mounted to the starter mounting ears and that the metal has been exposed. avoid engine ground points. aluminum soon develops an oxide that is resistant to electricity |
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Post by dollartwentyfive on Feb 17, 2017 20:27:21 GMT -5
The starter motor turns when it isn't mounted and the start button is pressed. Doesn't that indicate that the solenoid is working? yes, this indicates the solenoid is working. |
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Post by dollartwentyfive on Feb 17, 2017 14:46:37 GMT -5
I hooked the battery directly to the starter and the starter won't turn over. Thinking the starter was bad I pulled the starter. I then connected the scooter wiring to the starter turned the key on pushed the start button and it turned over. I am really confused. What would make my starter not turn over when in the housing but work when not inserted? How could this be related to the reversed battery? Isn't the starter clutch all mechanical? The only other thing I can think of is that reversing the connections fried my brand new battery and it doesn't have enough oomph to turn it over. My battery voltage is 13.2 volts. Any ideas? do a quick check of the engine by trying to turn the engine over with a socket and ratchet on the variator nut. remove the spark plug, and give the engine a few turns, should turn relatively easy. if the engine turns over, then the problem is with the battery, the start circuit connections, or the starter, or solenoid. go through the steps i outlined in my previous post. reversing the battery did not damage the start circuit, although it might have damaged the regulator/ CDI, (doubtful), but neither of these are in the start circuit. |
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Post by dollartwentyfive on Feb 17, 2017 13:44:42 GMT -5
the only connectors of that type i kept was to the regulator and CDI.
i did away with all the rest, and used direct connections.
i would have used direct connections with the above, but it would have been difficult to replace them when needed.
the switches were purchased at a local electrical shop, and i water proofed them with bicycle innertubes.
my bike wouldn't run if there was even a hint of moisture on the road.
rewiring solved that problem.
yeah, she didn't look all that good, but i finally got it to where i was confident i could take it on a 300 mile trip without a breakdown.
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Post by dollartwentyfive on Feb 17, 2017 13:27:52 GMT -5
voltage checks with a voltmeter will not reveal dead cells.
a battery can read full charge on a voltmeter, but yet still be bad.
reversing the polarity will not burn out your starter, or the solenoid.
there are only 2 other components (regulator and CDI), but they aren't connected to the start circuit.
do a load test on the battery or test it with a hydrometer.
if you don't know how, then take the battery to NAPA or some other parts store and ask them to do a load test on it.
clean the terminals/ connections at the battery, the solenoid, and the starter.
if none of the above helps, then test the solenoid to see if it is actually closing.
remove both of the big wires from the screw terminals, press start button, and check with an ohmmeter.
should read zero ohms.
if you have made it this far, then there is a problem with the starter wires (the 2 big wires going to the starter), or the starter itself.
there is however the possibility that the engine is locked up.
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