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Open since July 17, 1999
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Hi. I am a student and really need this moped so I can get to class.
I have a yellow 1980 Honda Express that I purchased and it has some minor problems. The bike starts up half of the time, and when it runs it dies after about 15 minutes of riding. I believe this is because the pet-cock only gives fuel to the engine in the reserve position. I also notice that I constantly get a blueish smoke from my exhaust. This means that I am getting to much oil right? I think that I need to disconnect the oil pump and premix the fuel myself, is that right?
Also, I noticed that the the throttle valve when it is "fully closed" is not really closed all the way. When I peak through the air intake on the carb, I notice that there is still a small gap left. Is this normal?
Lastly, I had some trouble getting the spark plug off. I used the ratchet size that is suppose to be for spark plugs 5/8. What size is used for this moped?
Thanks a lot, I really appreciate and advice.
Nick
Posted on Oct 29, 2007, 4:29 PM from IP address 65.35.87.59
Heh,heh......I always tried to SKIP classes,myself...LOL!
(1)Well,yes,it's normal to have that small gap in the carb venturi(throat)so the `ped can get enough fuel and air to idle.
(2)The problem of running can be starving for fuel because of a dirty petcock screen in the tank(the opening for the `ON' position can be clogged),so start there by removing the petcock after FIRST checking that the fuel cap IS venting.SOME Express fuel caps have a VENT position and off position.If you have it in the off position,the tank can't vent.
NOTE: I worked on an Express once that if you turned it ALL the way to the stop on the `OPEN or VENT' position,it would NOT vent.You hadda put it just almost all the way to open and it worked.So watch for that.
(3)Take the fuel line off the carb and do your own test to see if the fuel flows and IF it KEEPS flowing for 3 minutes into a fuel can.............if it slows considerably or stops,you have a venting problem.
(4)If the above passes the test,re-install the fuel line and loosen the drain screw on the carb and see if it flows regularly also. If not,you have a restriction between the inlet and the bowl,which can be a fuel inlet filter clogged or a needle valve not opening or clogged seat of the needle valve.
The MopedWhiz always said to get `em running and they should get better as you ride them.
I say the same,but I would add one tablespoon of good CARB cleaner(not injector cleaner)to a tank of gas.
The most probable cause is a fuel restriction.Gasoline tends to gel and clog with long storage where no STABIL has been added or the cap is left to `vent' during storage.
(5)NOW.....if you tried all this,and it has good fuel flow,you need to check for spark when this `no-start'or `quit after running' condition occurs.This is because a CONDENSOR,when bad, can quit after it heats up a little(Motobecanes are notorious for this).
(6)Important! Main thing to do with a moped when the problems occur is to REPLACE the spark plug with a NEW one.You can't tell by looking at one if it's good.They tend to misfire once compression is introduced with wet fuel mixture.
(7)be gentle when doing anything on a moped head or even replacing the spark plug.Don't replace them when the moped is HOT.....wait for the aluminum to become stronger when it cools a LITTLE...maybe 10 minutes.
NOW for the oiling problem:
(A)If starving for fuel it will smoke more when cold.The oil ratio is higher.
(B)Do a search about unhooking your oil pump if you really want to do that.......but replace the existing oil in the tank with fresh,high quality synthetic INJECTOR type 2-stroke oil(I like Pennzoil synthetic or AMSOIL).
Just make sure you have at least 32:1 ratio gas to oil getting into that engine.
I hope all this might help you a little,and GET TO SCHOOL by any means......except scooter(snail)of course!
JUST kidding! don-ohio (:^)
Posted on Oct 30, 2007, 8:50 AM from IP address 207.69.137.25
Hello, if anyone out there can help, we have a customer with a gyro carb but missing the slide needle. Would anyone know the number from the slide needle, i.e. 76H etc. I would apprecaite it.
Thanks
Harry
Posted on Oct 25, 2007, 8:20 AM from IP address 65.93.150.16
i have a 1986 honda spree that runs but dies shortly i cleaned the carb and was wondering wat people recommend also does any one know if there is a place to look at shop manuels online
Posted on Oct 21, 2007, 9:08 PM from IP address 24.219.13.163
I have a 1982 NC50 Express. When I open the throttle, I don't get nice, smooth acceleration, but rather the engine cuts out, sometimes for many seconds, and then usually, begins to accelerate, but rather poorly. I've done the easy things like replace spark plug, checked that air filter is not obstructing intake, and tinkered with the fuel-mixture adjustment screw. BTW, when I turn the fuel-mixture screw, it doesn't seem like I'm getting any response (no increase/decrease in engine rpm. Any ideas on how to improve this poor engine response during acceleration? Thanks!
Posted on Oct 13, 2007, 11:55 PM from IP address 67.150.218.13
Remove the carb. Check the emulsion tube. You can use a wire from a wire brush. It won't go all the way through. However it should go the length of the tube plus a little. Be careful not the hurt the tube.
You should be getting good response from the air screw at idle.
Posted on Oct 25, 2007, 4:16 PM from IP address 75.45.217.66
I am really hoping someone knows of a fairly late model moped which has multi-gears. Low gear for steep hills, mid gear for most riding, high-gear for long strait riding., etc.
The multi-gears are important since mopeds have small motors.
I also need the multi-gears for peddling.
I hope this is common. I ask the forum since most small 50cc scooters have only one gear (not good for hills and not fast on level ground)
I want to search this further, but I don't know what keywords to search for.
Ok thanks. I appreciate!
Erric
Posted on Oct 2, 2007, 11:49 AM from IP address 64.147.15.130
I dunno anything about them. Make sure they are 50cc or less and can be titled and/or tagged as mopeds first.In Ohio we have to have a Motorcycle license just to ride a Honda Express or anything without pedals. don-ohio
This message has been edited by don-ohio from IP address 207.69.137.20 on Oct 9, 2007 12:37 PM
Posted on Oct 6, 2007, 12:43 PM from IP address 207.69.137.10
I have a 79 Express2, and was told that it had a 3 speed tranny. I can only feel, and hear it change once. On the upshift, it changes around 15 MPH. On the downshift, it changes at around 10MPH. When should it change into either 1st or 3rd, whichever is missing?
Posted on Sep 24, 2007, 4:24 PM from IP address 216.12.82.89
Hey there guys. I been reading through the site and I hope you can answer a ?? for me, not about mopeds. I just bought a 2007 mini chopper for my g/f b-day. Its 49cc, 4 stroke, 4spd with auto clutch, the only #'s I can find on it are, HS1P39FMB & 05037203. I got it used, so no paperwork or manual.(any help identifying it??) I don't even know who makes it. Now for the major problem. Anytime you go into 1st or 2nd, it wants to HAMMER it into gear!! So bad in fact that it wants to shift the rear of the bike violently & it sounds like its going to come apart!! Even at idle & standing still, very audible CLANK and shifts the rear end. 3rd & 4th aren't too bad. So for now we start it in 2nd gear with the electric and go, to prevent further damage. Any idea on what I can do to fix it? replace 1st n 2nd gears? Or will I have to replace the trans? Whats the cost? Thanks for having a look at my problem guys. Hope you can help.
Posted on Sep 23, 2007, 9:12 PM from IP address 24.178.63.47
I have a 1978 Honda Express moped. I just took it to a shop to get the carb cleaned and a tune up. It tops out at about 27 or 28. The mechanic said it has a limiter on it which keeps it from going any faster. Do you guys know anything about this? Is there anything I can do to get it to go faster or even remov the limiter? I live in a city where all the street sign are 30 MPH and that means everyone wants to go 35 MPH. I also don't have any blinkers. Is there a blinker kit I can pick up for this old bike? Are there side baskets for the back wheel to throw books into? Thanx. Ryan
Posted on Sep 12, 2007, 9:07 PM from IP address 69.131.14.100
Expresses sold in Iowa had restrictions,but I don't know of any others.
The limit on a 2-stroke can be a small main jet,but can also be a washer inside the exhaust pipe inlet OR a small intake pipe.
When the muffler gets carbonned up it restricts power and rpms also.
You CAN kit(to 70cc) your Express and then put a performance pipe on it(or you can just put a performance pipe on it and install a bigger main jet while opening your intake air flow up some.That would probably get you to 40 mph with proper carburetion.
Do a search here for stuff like that.Hit `cached' when your results comes up and it will get you to the right page of this forum where your info. might be.
Use EXTRA oil in your mix if you kit it and use only high-grade synthetic blend or full synthetic.
www.westernhillshonda.com www.vtcycles.com www.dratv.com www.partsfish.com all may be of help.
You can get bicycle blinkers(battery powered)from different bike dealers or E-bay.
Baskets are available, but a storage trunk box adapted to the rear carrier would be best.E-bay again. don-ohio
Posted on Sep 15, 2007, 6:55 AM from IP address 207.69.137.15
What is a main jet? I don't think the limited speed has to do with exhaust, but not sure. Does anyone know exactly what is limiting the speed on this 78 Honda Express. What does a "kit" include? I don't have a problem with acceleration. It's just that every time it gets up to about 26-27 mph, the power automatically stops transferring. It seems like it might be an electrical governor or something. Hopefully I can simply remove whatever is causing this. Ryan
Posted on Sep 16, 2007, 10:34 PM from IP address 69.131.14.100
On a 1978 Honda Express, how is the key switch held in place? I have a lock cylinder in a plastic frame and a tree pronged pice that it fits into, but I don't know how these are held together and secured to the headlight housing.
I am making progress on this. I never saw a carburetor so gummed up before and I am not sure it is all clean as it only runs for a few moments before cutting out and I think the tiny passage for the choke feed is clogged too. It is a great scooter, much nicer than the very nice green '78 I used to have.
Thanks again for any hints,
Justin
Posted on Sep 10, 2007, 7:51 AM from IP address 70.101.75.24
It starts and runs well. It won't idle even with the Throttle Stop all in.
Question: Who has or can explain the Air Screw Circuit?
Behind this Screw it goes into the carb and there is a Brass stand pipe into the bowl. Should the Brass stand pipe be clear to the carb? I understand there are little orfices in behind the Screw.
Thanks much.
Posted on Sep 10, 2007, 4:38 AM from IP address 75.45.192.233
...........in those little carbs. You have adjusted the idle mixture screw(lower of the 2 screws)about 1.25 to 2.25 turns out from all the way seated?
Usually on an Express,with a dirty carb, the bike won't accelerate with power.
The brass tube with the holes is the emulsion tube.From bottom to top,it must be clear. don-ohio
Posted on Sep 10, 2007, 8:31 PM from IP address 207.69.137.40
How can I tell when the emulsion tube is clear. I do not believe it is a straight through tube from bottom to carb orifice in venturi. Or should I be able to get a bread tie through it.
I have tried spraying cleaner and air through it. I do not understand what it is suppose to be like when it is clear.
Bike is fine off idle. Steve
Posted on Sep 11, 2007, 1:56 PM from IP address 136.2.1.153
...........are a hollow tube,with the pinhole in the side letting fuel escape in to the ventura(throat or bore) of the carb.I haven't looked at an Express tube for a long time, but it is probably hollow. don-ohio
Posted on Sep 12, 2007, 7:33 AM from IP address 207.69.137.11
I think I got. I read somewhere that a Wire Brush wire is better than a Bread Tie.
Wire Brush wire is smaller and sturdy. I was able to push it into the emulsion tube. I felt it breakout the debris in the top of tube. Now fluid does flow through tube from the bottom into the Air Screw port and into the Carb orfice.
Posted on Sep 14, 2007, 11:37 AM from IP address 136.2.1.153
............than bread tie wire....stiffer.
I started to post that to you,but I wasn't sure that a wire brush wire would be long enough.
Usually what I do is get a stranded copper wire and get a strand of sufficient stiffness to run through the passages,since copper is less likely to scratch than steel,but if you're careful,you're okay with steel.
I hope that this will help your bike run right? Let us know? don-ohio (:^D
Posted on Sep 15, 2007, 6:34 AM from IP address 207.69.137.41
This is my second 78 Honda Express but sicne the last one I have forgotten how to disassemble the carb. The throttle seems stuck. I remember once on the old one installing it incorrectly and not being able to work the grip control and this is similar to how this one feels. Can't move it more than a smidge and it is stuck in the carb.
Any ideas?
Thanks for any help. Otherwise this has 47 miles on it and is coming clean with nice shiney chrome too.
Justin
Posted on Aug 29, 2007, 9:17 AM from IP address 70.101.75.24
........if the cable might be stuck, OR the slide is sticking in the carb.
There's a blow-up of the carb on this site,right? If not,go to www.mopedriders.com and look at their's under `moped repair' and the manuals will come up.
It's basically that you need to operate the carb separate from the cable,and see if it's the carb or cable's fault.
don-ohio (:^D
Posted on Aug 30, 2007, 7:02 AM from IP address 207.69.137.24
1st moped - help/advice for 89 Derbi Variant purchase
by
(no login)
Hello,
I am looking to purchase my first moped. I ran across a 1989 Derbi Variant Sport that was being sold for $100. It looks like it is in nice condition but it does not run. I have been looking into the Derbi and it sounds like it is a great moped but a bit rare to find parts.
I live in Orange County Cali, close to Myrons Mopeds, so maybe the parts can easily be found there.
Is this a moped which can easily be repaired? Will the replacement parts be arrordable even though it is rare.
Any thoughts on this bike and situation would be most helpful.
Thanks,
Micah
Posted on Aug 19, 2007, 11:16 PM from IP address 69.105.21.180
Anyone that can help Ron, answer this,okay? Thanks!
Ron's post:`I hate to bother you with this as I should be able to figure it out.
This has an automatic choke and by disconnecting the hose's and hooking
2
together it will start but will not accelerate. I have tried to find
an
automatic choke but no on has any . The guys that repair them tell me
they rarely go bad. Don' t make sense to me. Thank you for any help.
This thing has 125 miles on it . Everything looks to look brand new.
Ron.
Posted on Aug 15, 2007, 7:54 PM from IP address 207.69.137.6
.....www.mopedarmy.com will have a lot of info. on your bike which probably has a Minarelli engine.
Most bikes with batteries need one in place to absorb extra voltage from the rectifier(sometimes called a voltage regulator).
don-ohio
Posted on Aug 2, 2007, 5:22 PM from IP address 4.224.201.209
We have checked the ignition and spark plug and it sparks. We have cleaned the carbuerator and fuel lines. It still won't start. We think its the mixture, because we had earlier messed with the screws ut we arent for sure. Before we started, the engine would run for a little while, but then it stops. Now it wont even start. Any suggestions???
Posted on Aug 1, 2007, 2:17 PM from IP address 70.130.37.78
Okay,if it's sparking,then it is probably not getting fuel.
Is your throttle cable pulling open the carb slide?
Have you sprayed some starting fluid into the air cleaner? If it runs or fires on this,you probably have a plug somewhere not letting the fuel thru the carb.OR in rare cases,the crank seal may have blown,in which case the vacuum needed in the crankcase won't pull the fuel/air mixture down thew intake throat.If you remove the spark plug after trying to start it and it's wet with fuel,it's just probably a very weak spark.
The first thing to always do,is REPLCE the spark plug with a new one.You can't tell by looking at them if they're firing properly. don-ohio
Posted on Aug 2, 2007, 5:29 PM from IP address 4.224.201.209
I have a 1977 Honda Express (NC50). Last night the throttle cable broke, or at least came loose from the twisting handgrip. I unscrewed the cable from the handlebar, and the end looks frayed. (This happened when I was a couple of miles from home, in the middle of the night. I made it home, slowly, by manually pulling on the remains of the cable enough to keep the bike going, and thanking God I didn’t have to walk the thing back.)
I assume I’m going to need to replace the cable. So, I have two questions:
(1) How do I open up the twisting handgrip housing to pull out any remaining pieces of the old cable, install a new one, etc.?
(2) Where can I get a new cable?
Thanks.
Posted on Jul 31, 2007, 4:51 PM from IP address 66.136.174.210
Hey there,
Just got an 81 NC50 from our neighbor. He was throwing it away, so I grabbed it thinking I might have fun with it. The first think I noticed was that the front wheel is locked up...won't turn. What could be the cause of this, and what could be the cure? I am sure there will be lots of other questions, but this one looms largest. Another question I'll ask now is can I start the moped without a key? My neighbor didn't have a clue where the key might be. I look forward to your replies.
Posted on Jul 30, 2007, 3:20 PM from IP address 74.241.105.54
Also can be locked wheel bearings if bike was submerged.
The key? I just look at the wires going to the switch and figure out which ones contact when the key is in the run position. don-ohio
Posted on Aug 2, 2007, 5:33 PM from IP address 4.224.201.209
i had the same problem. i asked my local honda dealer and there is a number on the side of the ignition switch that tells them they keys cut. so if u have local honda dealer ask them
Posted on Aug 6, 2007, 6:33 PM from IP address 216.51.248.45
