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Open since July 17, 1999
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Zippy thanks for the help you were right it was the idle jet clogged and no I did not know about that. It runs great now and idles real well. How would I go about checking the oil injection pump on this vespa grande? Do these pumps usually last along time or are they a problem? My bike has about 180 miles but has sat unused in the barn for about 20 years.
BILL
Posted on Jul 4, 2004, 9:22 AM from IP address 24.61.237.211
Glad you found the Idle jet and have it running smoothly now.
Also check the final reduction gear (transmission)in the rear hub by opening the access screw or bolt on the left side of the hub near the Free Wheeling black plastic button. If oil runs out, its full, if it doesn't add 80-90 wt gear oil. They sell this oil in plastic bottles that have a nose cone like a mustard or ketchup squeeze bottle.
I don't have a manual for your Grande (in fact I have never seen one just for the Grande) but the Puch Service manual gives this procedure for testing a Puch Magnum MKII oil injector pump.
Make sure you have premix (2% or 2.5 ozs of 2 stroke oil to 1 gal of gas mix) in the Grandes gas tank for this test, else you couuld damage your engine from no lube.
Fill the 2 stroke oil reservoir tank with a good 2 stroke oil , I recommend a synthetic 2 stroke oil. Make sure there are no air bubbles in oil line to the pump, in other words the oil line should be full with oil running out the end of it ,when you reattach it to the oil pump intake.
Pull off the output oil line that comes out of the oil pump and goes into the carb or intake manifold (I'm not sure where it is on your bike). Put the free end of the oil line into a clean container to catch the oil as it is pumped.
Start the bike and run it for about 4 1/2 minutes at about 3500 rpms (probably about half throttle or a bit more) Judge by the sound you think the engine would make if you were crusing at about 20-25 mph.
The Puch oil pump is supposed to pump out about 10cc + or - .1cc during the 4.5 minutes at those RPMs. Puch Magnum and Vespa Grande both recommend a 50:1 or 2% mix so I would assume both models oil pumps should pump about the same amount of 2 stroke oil.
If it doesn't pump anything check the oil tank and line for free flow of oil. If it still doesn't pump, you have a defective non operational pump. If it does pump and pumps the correct amount, then you are OK to use it but make sure to do an oil pump test about every 200-300 miles.
Your Grande is a very low miles bike and really hasn't been completely broken in. You are not supposed to exceed 15 mph for the first 300 miles on most mopeds and don't strain the engine too much with steep hills or heavy stress on the engine(such as carrying extra weigh like a passenger). You can vary the speed but don't exceed 15 mph for extended periods. After 300 miles you can open it up but back off on the throttle going down long steep hills and use the brakes to keep the engine from exceeding top end RPMs.
If your bike dies while you are riding or the rear wheel seems to lock up and the bike stops and dies but will restart after cooling off, that is probably a "soft seize". This means the engine was running too hot from lack of lube or improper mix or timing. If this happens, switch to using premix and pull the oil line from the pump and plug it.
The last little quirk the Vespa mopeds have is if the brake light burns out your moped will die each time you apply the brakes. Fix is, replace the dual filament bulb or pull the brake lever brake switch wires as a temp fix until you can get a bulb.
Hope this helps. You have a very nice rare Grande. I have only seen two in the last five years.
Email me some pics if you can.
Happy Trails
Posted on Jul 5, 2004, 1:33 AM from IP address 24.7.114.224
i took flywheel off and took stator out and noticed that there as a thin wire coming off one side wans not connected top anything, it is not a mitsuba, it the other one,
if that helps,
i need help to get this cheap moped to spark so i can get er running, i only paid 20 dollars for it told the guy that id buy it as parts, but may try to get a title for it
help will be apricated
Posted on Jul 4, 2004, 2:06 AM from IP address 216.51.207.87
I have been putting this Express back together, but without manuals etc...How is it started? Also is the battery supposed to have both neg and pos. male connectors or just use the pos.? Any help is appreciated.
Posted on Jul 3, 2004, 4:09 PM from IP address 64.90.78.207
TO start the bike, you turn the key to on, the red kill switch to on, hold the choke on, press down on the starter lever 5 times and then pull the back brake handle. If it starts, it starts. If it doesnt, I suggest you read the guide I wrote on getting a garage sale express started.
The most revised version is at http://www.mopedarmy.com/forums/discuss/6/5035/5035/
As for the battery, it should have two leads coming out of it. Posative and Negative.
Posted on Jul 3, 2004, 10:11 PM from IP address 154.20.89.136
I have a 1978 Honda Express NC50 It runs fine and i have cleaned the carb. but the float stills sticks every once in awhile.. I wanted to know if anyone can let me know where i can get a Carb Kit or Rebuilt Carb???? Thanks Jeff
Posted on Jul 2, 2004, 8:04 AM from IP address 67.167.47.22
Assuming the float actually floats, your best bet is probably a new needle. They are a $2.75 part from a motorcycle shop. Bring yours in and they can match it up.
Posted on Jul 3, 2004, 2:24 AM from IP address 154.20.89.136
I noticed www.50cc.nl also has parts for the NU50. They are in the Netherlands but a lot of mopeders have bought from them and they have a good reputation.
Posted on Jul 6, 2004, 12:01 PM from IP address 24.7.114.224
I have a 1981 Honda Express I just purchased. I can't seem to find an oil tank. I found the oil and fuel pump, but the oil lines run up to the gas tank, was wondering if anyone knew if it was a mixed gas or if there is a oil tank somewhere? help needed, thanx.
Posted on Jul 1, 2004, 8:23 PM from IP address 207.14.76.66
I have a 1978 vespa grande oil injected model that sat for many years. It has 178 miles on it. I did all the usual stuff to get it running again, clean carb,points, flush tank etc.. I can ride it at 30 mph but as soon as I back off it and come to a stop it dies out. Could my problem be the oil pump or would it have seized after riding for a few miles on just gas if it were not pumping oil?
BILL
Posted on Jun 30, 2004, 3:03 PM from IP address 24.61.237.211
Check to make sure your brake light bulb is not burned out. It will kill the engine each time you apply the brakes if it is.
Did you know about and clean the Idle jet in the carb throat?
It is in the side of the carb that goes on the intake manifold pipe. There is a round tubular plastic shim or collar you have to remove to get to it. After the shim is removed, when you look in the carb throat you will see the vertical brass tube with holes in it (thats NOT the Idle jet). Follow the brass tube on down to where it stops at the aluminum carb casing and look just below in the aluminum casing for a tiny hole, you may have to tilt the top of the carb slightly away from you to see the hole. That's the idle jet. Use a small piece of piano wire or a single strand of a control cable to clean out the hole and then use wd40 and air to blast out the hole.
It should idle OK after the cleaning.
If you are going to use (trust) the oil injector it would be a good idea to darin your gas and put premix in your tank to run on while you test the oil pump to make sure it is pumping the oil.
I always run premix, I don't trust the old 20+ year old oil pumps.
Posted on Jun 30, 2004, 11:47 PM from IP address 24.7.114.224
I am a 18 year old male from northeast Nebraska. I used to ride my 1978 Honda Express alot and post on this site, but my moped has sat for about the past year. I decided to pull it out and try and get it started, but it will not start. I know I have spark, fuel, and the carb is clean. Right befor I quit riding it, I changed the the part that is between the head and the crank case(I supose you could call it the "block") because I was bored. I have a seperate junker moped I got the part from, I didnt buy anything. I also was not running an air filter ( I know that was dumb). Changing that part made it run like a champ, I gained about 2 mph, which was huge for me at that time. Now when I try to start it is doesnt go. When I turn it over it just sputters a couple times and dies. I contintued to keep trying to restart it, and it would progressively turn over more and more. Then after about 20 minutes of trying I got it to start, but it was puffing out huge abounts of blue smoke, and it ran really crappy. I let my friend control the throtle while I adjusted the carb. My friend let the engine die and I never got it started after that. I am fairly well educated in eninges and I dont know what else to do. Please help.
Posted on Jun 29, 2004, 7:49 PM from IP address 204.183.157.116
I was wondering how tight the large sprocket should be.Mine is very loose....maybe 2+ inches.My second question is....can I run 93 octane in my moped?.Any feedback would be greatly appreciated....Thank you.
Posted on Jun 29, 2004, 7:36 PM from IP address 24.196.115.46
I've taken ownership of a 1982 Iowa Urban Express. The tank is clean, and the gas flows to the carb. I've cleaned the carb, and checked that it has a nice big spark at the plug. I resorted to stuffing a towel in the itake of the air cleaner box, and after some more kicking, it started up. Some fiddling with the idle screw on the carb and it settled into a nice idle. As long as the engine was still warm, it would start back up with one kick. After I let the engine cool down though, I had to stuff a towel in it agian. Then, same story, it started, adn would continue to start as long as it was warm. Once it cooled of a second time though, no amount of kicking or stuffing would get it to go. Still plenty of gas flowing, and still a strong spark. This time I noticed the tail light wasn't coming on when the key was turned on. Someone help me, please...
Posted on Jun 29, 2004, 12:18 PM from IP address 12.217.81.66
Your Nu50 is equipped with an automatic choke of sorts. If you look on the right side of your engine, on the cylinder head, there is a valve body with 3 lines running to it. Be very careful if you try to remove these lines, they connnect to plastic that breaks easily. One line feeds gas into the valve, one feeds air, and the last goes to the carburetor. There is a bimetallic strip inside that senses engine temperature. When cold, it directs gas to the carburetor. When warm, it's a gas/air mix. When hot it's just air. There is a spindle inside that slides back and forth to open the correct pathway for what is desired. If this is stuck, you may not have any choke operation at all. I'll bet that if you hold your throttle wide open and kick the bike about 10 times, it will start.
Posted on Jul 1, 2004, 4:00 PM from IP address 24.161.57.200
Thanks, I'll try holding the throttle open to see what that does. I'm also guessing that since the screw heads on that auto choke thing are painted, they can't be opened and fiddled with, but I might just try anyway. I also have a 1984 Elite 125. The auto choke was not working on it either when I got it.
Posted on Jul 2, 2004, 5:14 AM from IP address 12.217.81.66
Quick question. My 82 Honda express runs poorly. It has about 1300 miles on it. There is clean gas in the tank. It starts up no problem. The rear wheel slightly rotates. I think I have the air and throttle settings on the carb correct. (air about 1 1/4 quarter turn out). I can only get the bike up to about 21mph, and during so, it will bog down slighly, and then bog around 21 if i give it too much throttle. Previously I could get it to 30-32mph. I cleaned the carb out about a month ago. I emptied some gas into a paper towel and didn't see any rust or dirt. Should I take apart the carb again and clean it? I haven't checked the exhaust, could it be carbon build-up? It has a new spark plug. Any ideas?
Thanks!
Bill
Posted on Jun 28, 2004, 9:41 AM from IP address 135.214.42.162
Checking for carbon would be a very good idea. It took me about 35 miles to go from 31MPH to 26. All due to a bottle of cheap gas station oil.
When they say Use only honda two-stroke injecter oil, they mean it.
Disconnect the muffler and see how it runs like that (besides loudly).
If you suddenly have a top speed of 32 then you should just need to clean out your exaust port and the muffler.
Posted on Jun 29, 2004, 2:56 AM from IP address 154.20.89.136
How exactly am I suppose to disconnect the muffler? It looks pretty much welded on to me. If I can take it off, I can test to see if the muffler is at fault.
thanks,
Bill
Posted on Jul 12, 2004, 10:13 PM from IP address 4.14.95.53
I have 4 urban express' on the road now and they all have front brake squeal that hasn't gone away even though I have replaced the shoes on two of the bikes and logged about 150 miles. Does anyone know how to stop the squealing?
Posted on Jun 27, 2004, 5:00 PM from IP address 24.161.57.200
be sure to clean the inside surface of the hub/drum even the edges where you think the shoes/pad don't contact
also do not over tighten the axle nuts, this puts compression stress on the hub ans sets up conditions for stress vibration while braking that can add to the squeal
TheMopedWhiz
Ride Mopeds..SAve Gas..Have Fun
Posted on Jun 27, 2004, 6:10 PM from IP address 66.174.76.205
i have my starter motor working, but not getting any spark i think. i just cleaned the fuel tank and filter out. i guessed the lines would get some air in them and die for a little while. but now i dont think im getting a spark.
somthing shorted out when i was trying to get it to start. the wire coming off my harness going to ground the bike out made alot of smoke and the rubber burnt off the wire. i taped that all up,but now i think the part that produces a spark to the plug is bad.
what do i test for?
Posted on Jun 26, 2004, 4:30 PM from IP address 67.160.30.178
ive got it to give a spark every few times it try to start it. i think it should be getting a steady rythmic spark tho right? im guessing the ignition coil is shot, or could be somthing else more likely?
i messed up the ground wires while trying to jump the battery from my truck. the + cable managed to contact the frame and battery at the same time.
Posted on Jul 3, 2004, 12:34 PM from IP address 67.160.30.178
when trying to remove the flywheel it stays inplace and the crankshaft turns so what is the best way to hold the crankshaft so i can remove the nut thanks alot brian
Posted on Jun 24, 2004, 10:24 PM from IP address 209.112.146.70
Eather get yourself one of those infernal flywheel holders or find someone with an Air Impact Driver. One quick hit with that and the thing's off. works great to put it back on too.
THW: comments
pull the tranny cover on the left side of the engine
then you can brace/block/lock the crankshaft from turning
the honda tool for holding the crank still: GOES on the tranny side
This message has been edited by themopedwhiz from IP address 69.83.181.187 on Jun 25, 2004 9:50 PM
Posted on Jun 24, 2004, 10:46 PM from IP address 154.20.89.136
thanks alot fro the help got the flywheel and altonator remove just wating for some parts so i can get evorything balck to gether thanks alort Brian Wilcox
Posted on Jun 28, 2004, 1:39 PM from IP address 209.193.29.111
When I first got my 2002 Alpha Sports (Aeon) ls50 I couldn't drive it 5 minutes and it would die. Inoticed a suction in the gas tank as I removed the cap. Not haveing two lines to the carb I suspected it as rather odd. Out of desperation I made the smallest of slits in the gas cap gasket. After that it was totally reliable.
Posted on Jun 24, 2004, 8:58 PM from IP address 12.73.134.74
need help how do you remove the magneto alternator from a 1977 n c50 express read posts just couldn’t find info on how to remove the magneto alternator along with the flywheel any help greatly appreatchiated
Posted on Jun 23, 2004, 9:05 PM from IP address 209.193.54.231
To remove the cover you undo the bolt at the top at the screw at the bottom. The cover just comes off.
To get the flywheel off you can do one of two things.
The manuals I have say to use a special Flywheel Holder tool which goes into the openings and lets you hold it in place while turning the nut with a wrench. This way is a pain in the butt.
My solution was to use an air inpact driver to simply take the nut off. Worked great, and also put it back on tight.
As for taking things apart any further, a good service manual would be more help then me.
Dare I ask what your goal through all this is? you may not need to go in as far as you think.
Posted on Jun 24, 2004, 1:40 AM from IP address 154.20.89.136
