Tuesday, May 25, 2010

Honda Express Moped Poor Performance High Speed (Highend Speed)

Honda Express moped - loosing performance all of a sudden at high speeds (high rpm's). What's going on???

So, recently I neglected to check my nc50 express moped oil level and I came close to running out completely. I luckily checked before it was too late. Had I waited too long, the honda engine would have eventually seized. Side Note: You can check the oil level using a little see-through window in the gasoline/oil tank on the back of the honda express. [see diagram]

So I filled up all the oil reservoir with new Lucas Semi-Synthetic 2-Cycle Racing Oil. I then rode my Honda noped to work and 5+ miles into my ride, I noticed poor performance at high rates of speed. Just a few days ago I didn't have any trouble going 30+mph on the moped, but now I can't get over 25 mph. My honda express moped top speed totally decreased and isn't changing. I can also feel the engine "pulling back" or lacking power at the top honda speed ranges. It has no problem accelerating though.

I have been trying to deduce what the problem is. The only thing that has changed in the past couple of days is the oil situation. I was running the 2 stroke (cycle) moped oil from the previous owner. I don't know if he had put in low grade 2-cycle moped oil or high performance synthetic oil. I am betting he used the cheap stuff. Does that mean I should use cheap stuff or good stuff?

After doing research online I have found many fellow moped riders LOVE synthetic 2-Cycle oil. In particular, I discovered many riders stand by AMSOIL DOMINATOR® Synthetic 2-Cycle Racing Oil (TDR). Perhaps I should give this a shot. Maybe my Lucas oil just isn't cutting it.

I will continue to repair my problem and post my results here. Perhaps a video on how to remove the Honda Express Engine Oil Pump??? We shall see... stay tuned and check back often for new posts.

6 noped comments:

Anonymous said...

I'd love a video on how to remove the oil pump. I just switched to premix and just looped it, but I would rather just take the thing off. Been lurking on the site for a few months now its helped a lot thanks!

jfk said...

DONE! The footage has been shot and the process was successful! I just have to splice the video together (doing a little out taking) and I will post it. I will embed the video when done. It is Memorial Day weekend here in USA this weekend and I have friends visiting. I hope to splice video and have it posted mid-to-late next week.



Unknown said...

Hey jfk I am having that same problem you described previous. The bike will accelerate fine till it gets to the top speed area and then just kidna dies and rpms lower. Once it gets to a point it will let me use more throttle. But when the bike is supposed to be hitting top speeds it just goes on a downhill climb and wont let me accelerate. Did you ever find a fix for this? Ive just been using a regular 2 cycle oil non syn. But if you could get back I sure would appreciate it. Thanks

Unknown said...

Hey guys, I just switched to pre mixing my nc50. Right now i have the oil pumped looped also. Do you know of anyway where I can take the oil pump out and somehow seal up the hole were it used to be? I have just been wondering what I could do. Figured you guys might be able to help me out.
Thanks Josh

Unknown said...

i have the same problem. at top speed, if i dont let off the throttle it continues to bog down. did changing the oil solve the problem?

jfk said...

@al & lyndey,

Try adjusting air/fuel screw on carb. I found that my stock muffler was restricting my top speed. Try modifying it or getting performance exhaust.


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