Honda Express Running Poorly

I recently purchased a 1980 Honda Express II NA50, it only had 127 miles on it when I purchased it. After riding it a few miles it gradually lost power and killed. I had to restart it 5 or 6 times to get it home. After that experience, I replaced the spark plug and battery, hoping that it just needed to be run for a while to get the old gas and oil out of its system. Now, after about 100 miles put on it and only the occasional kill, it seems to have reverted back to its original condition. The engine loses power and needs to be constantly revved to keep from killing, and the spark plug is just as gross and grimie as the one i replaced. Am I getting too much oil, or not enough gas released, or do I need to drain and replace the oil, or do I need to give it an all around tune up? If I need a tune up how should I go about doing this. Thanks for your help everyone!

Re: Honda Express Running Poorly

Jonas Quimby /

I'd guess that you need to clean out your carburator and then set the adjustment screws right.

I wrote up a guide to getting a garage sale express running which covers carb cleaning and setting a bit, as well as some other common problems and tips.

Keep in mind that the express and the express II are a bit differant, but mechanicly as just about identical.

https://www.mopedarmy.com/forums/discuss/read.php?f=6&i=5035&t=5035

Take a look at that and post a message if it doesnt help.

Re: Honda Express Running Poorly

Jason Rundle /

I was starting to take of my carburator and I noticed something funny about my fuel line. I can see air in it. About half of the visible tube is filled with air. I would think that since the gas tank is about half full, the whole thing should be filled with gas. There is even a little bit of air in the tube past the little cone looking fuel filter thing. Is this the cause of my losing power? Is the fuel line from the gas tank somehow clogged, or is this a normal sight.

Re: Honda Express Running Poorly

Drain the old gas out of there.

Re: Honda Express Running Poorly

Jason Rundle /

I took off the gas tank and cleaned out the little cone shaped gas filter in the gas line leading from the tank. A fair amount of sediment came out. I also experimented with the stopcock while the tank was off. I found that the open position would not let very much gas through compared with the reserve setting. I put the tank back on and tried to get most of the air out of the recently emptied gas line. I also replaced the old oil with brand new stuff. This time I put the switch to reserve. None of this seemed to do any good. The moped still loses power between 15 and 20 mph, even lower going up hills. And you have to keep it at these speeds with occasional revving to prevent it from dying. Until about a week ago it would go 25-27 mph on flat ground with no problems of losing power/dying. Do i need to proceed to cleaning the carburator?

Re: Honda Express Running Poorly

Leon Swarmer /

if you had gunk in your tank, it prolly went into the carb too, at very least pull your fuel bowl off and dump and clean it.

you'll prolly have to clean more of the carb though.

Clean the petcock again, too you want a good fuel flow on On so you don't have to rely on reserve.

leon

Re: Honda Express Running Poorly

Jason Rundle /

Hey guys!

I cleaned the carb with some cleaner and now it works great! Back to her old self again. I just have some questions about the screws. I set both of them back to their original positions even though they were different then your suggested placements Jax. If I'm setting them, what should I be listening for, or feeling for when I'm riding it, so I can get the correct setting? Thanks so much guys! Man scooters are so much fun. I love my little Express.

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