Honda Express II

So I've been working on an old Honda Express II. Every once in awhile, it will start but it dies within a few seconds. I cleaned the carb, the float valve is free. I replaced the spark plug as well, however, I can't tell if it's getting any spark or not. This may be a stupid question, but does the battery need to be charged in order for it to start?

Re: Honda Express II

It should still run with a dead battery, but that's not a good idea as all the lights will blow due to the battery being dead.

Re: Honda Express II

Lucas Roberts /

Ok, could it be the plug wires? The rectifier? Bad engine timing?

Re: Honda Express II

Chris Holbrook /

it could be the timing (depends on if its a points bike), maybe the plug wire (easy check run it in the dark watch for arc), won't have anything to do with the rectifier alls it does is charge the bat. & run the lights (convert AC to DC).. the coil runs off straight AC current from the alt. to the plug wire.. i'd say if the thing starts & runs even for a few seconds its getting spark.. all you need to run one of these is air, fuel, & spark..

Re: Honda Express II

Chris Holbrook /

http://projectmopedmanual.info/

its got service manuals for this bike..

Re: Honda Express II

Chris Holbrook /

something that really helped me understand how simple the ignition sys really is.. check out this old post..

https://www.mopedarmy.com/forums/read.php?6,1844724,1844755#msg-1844755

Re: Honda Express II

Lucas Roberts /

I'll take a look at it tonight when i get off work. This also may be a stupid question but would it have something to do with there being no air filter for it at the moment?

Re: Honda Express II

Chris Holbrook /

no question is really stupid.. we ask to learn, or spend hours researching & going thru old posts ;) no i don't think so.. if you actually get the thing to run for more than a few seconds it would probably be a good idea to get a new filter to protect your carb.. while i am thinking about it did you check your fuel flow + filter? trash in the fuel tank? if you had any of these problems you'll have to clean the carb again, after you correct the prob.. air, fuel, spark

Re: Honda Express II

Lucas Roberts /

I had disconnected the line below the filter and it flowed freely. There was also fuel in the bowl of the carb when i took it apart. I think I may go ahead and poke something through the jet to make sure it's not clogged.

Re: Honda Express II

Hey Lucas, to answer your air filter question, you can try using something in place of the air filter, like a clean rag, or even wrap some nylons around the carb. It's possible you could just have way too much air, and it needs to be restricted, especially if this is a stock bike. It could be running way too lean. I would also check the spark plug gap.

Re: Honda Express II

Lucas Roberts /

I'll do that tonight as well. I'll let you all know how it goes.

Re: Honda Express II

Lucas Roberts /

Also, this thing doesn't look like it has an ignition key anywhere. It looks like it may have a spot where an ignition switch should go but other than that, nothing. I don't believe this to be a problem but later on down the road, I may want to get this fixed.

Re: Honda Express II

Hey Lucas, I bought a new ignition switch for my 78 Express from BikeBandit.com. It was so worn out that the key would fall out while I was going down the road! It was pretty easy to install. I bet they probably have one for your bike as well.

Re: Honda Express II

Lucas Roberts /

OK, definitely not getting any spark. Going to clean the Spark plug boot on the wire and see if that does anything.

Re: Honda Express II

Lucas Roberts /

So stripped the spark plug wire and put it close to my mountain bike to see if I could get a spark. I did. I attached it to my spark plug but, alas, nothing. Does the moped have a ground or something that may be unattached?

Re: Honda Express II

Chris Holbrook /

did you look at the service manual link i posted earlier? it has all the wiring diagrams.. & ignition coil tests, how much resistance (ohms) should be on what, volts etc. these are old bikes that have often not had the most pampered lives & alot of hack & chop to make stuff work.. it may be as simple as a connector not pluged up on your wiring harness.. or somebody splicing in a hurry & now its grounding out.. do u get any power from the alt when u kick it over?

Re: Honda Express II

Lucas, make sure your ground wire has good connections. Also, I would check out the spark plug boot and consider replacing it. Cut about 1/2 inch off the end of the spark plug wire where it attaches to the boot and screw the boot back in to make sure you have a good connection there.

Re: Honda Express II

Lucas Roberts /

Someone had put the wrong spark plug on the bike! I caught that a couple days ago and I now have spark. However, I watched the spark and when I attempt to start it up, there is a spark, then a pause, then a series of sparks at the end of the start cycle. There is also a lot of black liquid on the plug after I take it out of the cylinder. I am checking the points now to see if they need to be fixed. (taking the flywheel off was not the easiest of tasks.)

Re: Honda Express II

Chris Holbrook /

emory board nail file, 400 sand paper, spray can of electric contact cleaner, air compresor, can of starting fluid & an electric drill to use as a starter for the bike.. thats what i used when i first got my hobbit going.. get a couple more plugs so they can dry between trying to start.. once you get it going don't let it die or idle, run it half to wide open for a few min.s till you get to operating temp.. burn all that old trash outa it..

Re: Honda Express II

Gruff "(OFMC)" - /

also since your troubleshooting, it sounds like its super rich fouling adjust your carb to stock settings should be in the manual somewhere. the exhaust may be gunked up now with all the starting going on, you may want to disconnect it and burn it out if you get the chance. but definetly take it off while your trying to troubleshoot starting it , it could be an issue. see if it starts with it off. and since you have it off blow through it to see if there is blockage, it should be free with no restrictions when you blow through it.

Re: Honda Express II

Lucas Roberts /

Got a new battery for it today. That actually seemed to give it a thicker, bluer spark for awhile. However, it went away. I went ahead and got some new plugs to cycle through. How should I attach the electric drill to the bike? Straight to the nut on the flywheel?

Re: Honda Express II

Lucas Roberts /

The exhaust seems to be free of obstructions and clogs. I actually realized the jet was clogged on the carb yesterday so I cleaned it out. Still nothing yet. I'll try again when I get some more free time.

Re: Honda Express II

Make sure to clean the pilot jet tube next to the main jet tube. These are notorious for clogging because the hole is so tiny. It should pull out with some needle nose. If it wont come out do not squeeze harder, or you will crush the tube. Heat up the area with a small torch to get it hot, no more than a couple seconds of heat from a small propane bottle torch. Assuming you have the carb completely unhooked and you are working with just the carb body and everything else is stripped from the carb including the bowl seal. Heat it up at the base of the tube for a second. Then try and pull the tube out. Works every time for me. Also if you have a fixed main jet express carb you can pull and twist the main jet out if you can't seem to unclog it first. I only advice you do this if you cannot get the jet clean because 9 chances out of 10 the o-ring seal is brittle and with crumble after you have pulled the jet out.

Check your timing and points. Are your points worn? Is your spark plug cap threaded in to the spark plug wire tight? Make sure everything under your seat is connected including the battery. It depends on what year your express is. Later expresses have a square plug that must be connected to the battery to get spark.

Also unhook your kill switch behind your headlight and see if this changes anything. It will the black wire with white stripe coming from your throttle. Loose and faulty kill switches sometimes will cause this.

You can buy a new key switch for about 8 bucks shipped on ebay that works excellent for express'. You just have to cut the plug off and hard wire it to the existing wires.

http://www.ebay.com/itm/Key-IGNITION-SWITCH-Suzuki-Motorcycle-Dirt-Bike-ATV-/270960839407?pt=Motorcycles_Parts_Accessories&hash=item3f16864aef&vxp=mtr#ht_2799wt_952

Let us know what you find out.

Nick

Re: Honda Express II

Also stock air mixture screw setting is 1.5 turns OUT

Nick

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