Dead '78 NC50

Rich Secret /

I have a 1978 Honda NC50. I wanted to fix it up for my son to ride around the yard on. It was once running poorly and the muffler was loosened to allow exhaust to bypass the clogged muffler and it did run but again poorly so it was parked until I could clean the carbs.

He pulled it out the other day and it would not fire up. I pulled the carb, tore it down and cleaned it out. It was indeed gummed up. I put it together but still it doesn't fire up. I checked the plug, it can use a new plug but it does get some spark.

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A little history on this moped: the previous owner removed the battery and never replaced it. The moped did function ok without the battery, though the horn didn't work. The oil injector died while the previous owner had it and they had the motor rebuilt, they disabled the injector and started just mixing the oil into gas.

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I am no serious mechanic but know enough to muddle through most anything. If I take it apart I can put it back together.

I assume since the plug gets some spark that the coil is fine. The regulator/diode I assume is ok as well but unsure how to test it.

I put a little gas on top of the piston and put the plug in and gave it a kick, didn't fire up. I assume the plug is too weak or that perhaps something has happened to the wiring thats stopping it from starting.

As stated, I get some spark, just not a big fat one. Ideas?

Re: Dead '78 NC50

Rick...that moped NEEDS a battery, if you take it out, you will blow your lights, and i would imagine that you u could screw up any thing electrical. I didn't know that, and i fried alot of shit on my 78 nc50, just got it back together, and beleive me, it was a very expensive mistake,...the battery can be [picked up at any honda shop,..the one i just got was about 10 bucks.......yo,....spend a little now......save alot later......filley

Re: Dead '78 NC50

Rich Secret /
nc50 OP

Where did you get your battery? I just called the Honda dealership and was quoted $62.95. While I had them on the phone I asked for a price for new points and a coil. The points are not available and the coil was $48.68.

I am unsure yet what exactly I will need but I think the coil is going to need replacing. I looked it over today with my son and the wire that comes out of the coil (and goes to the plug) was not firmly hooked to the coil. After checking it out I found out that the wire was stripped back and shoved into the hole in the coil. I appears that the coil wire/sparkplug wire should have been hooked inside and the wire broke and the previous owner just shoved it in there enough to get a little contact. Does this wire supposed to merely pushed in? or is it supposed to be fixed in place?

Re: Dead '78 NC50

D&D Honda in Coldwater, MI. Just got it there on Friday. Yes the coil wire should be fixed in place. You can also get a battery for the bike on ebay for around $15 usually. Oh,.....I have a set of brand new points for this bike,....still in the original honda packaging. As for the coil,....sounds like another ebay item.

Re: Dead '78 NC50

ಠ_ಠ Jon Folks ಠ_ಠ /

Yea go ebay, save lots of money! Have you cleaned the points yet? If they are dirty thats a simple reason for your weak spark, and the most common.

Brooklyn

Re: Dead '78 NC50

Herb Norris /

Batteries Plus $15

Re: Dead '78 NC50

the exhaust is critical on a two stroke. i think it would at least sound like it was going to start though if that was the only problem. so i would follow these other kind peoples advice,however you must do something about the exhaust for it to run properly. two strokes are much different than 4 strokes in this regard

It Starts, but...

Rich Secret /
nc50 OP

First, I removed the muffler (its sitting with drain cleaner in it at the moment), I replaced the plug and the coil. I cleaned and filed the points and I guaged them to .016 (I think I did it correctly), I removed the carb, tore it appart and cleaned everything. I put it back together. I cleaned the gas tank and put it back on. I am getting gas and spark, compression is 90psi.

Crank it up and it starts. It runs rough and sounds like its about to die but keeps going then all of a sudden after idling for a minute it picks up and sounds like someone is giving it throttle, the back tire spins fast. If you put resistance on the tire in the form of brake or setting it on the ground the engine dies. Is this because the air and gas mixture screws need adjusting? Are the points set incorrectly?

Thanx again, guys (and gals)

Re: It Starts, but...

Leon Swarmer /

points should be between .012 and .016.

your should be ok.

did you check the timing after fiddling with the points?

:eon

Re: It Starts, but...

Jonas Quimby /

If you have the choke on when the bike is warm or if the idle mix is giving it too much fuel then it will do that.

Re: It Starts, but...

i would make sure the intake manifold is not leaking. to do this spray some starting fluid aroung the gasket using a peice of cardboard or whatever to keep the spray from going into the carb. if it races you have a leak which can sometimes produce these symptoms. if it is leaking you may just need to tighten it or replace/make a gasket

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