what the !!#@$$$%*&*&!!

When starting up my honda urban express nu50m it revs real high and after about a minute it comes back down and wants to die...but I can keep it running by just tweeking on the throttle. Finally, after about 5-10 minutes of doing this it will idle fine and run ok, but is slow coming down off of full throttle but eventually gets there. I have had the carb off 2 times and cleaned it thoroughly, and it appears to look ok. Is there a specific setting for the air/fuel mixture screw located at the bottom of the carb(underneath the idle screw), or just something even more simple? Please help. Thanks

Re: what the !!#@$$$%*&*&!!

Don Pflueger /

you havean air leak somewhere and as the engine heats up and expands, the leak gets sealed. sounds like a cylinder base gasket to me. replace it and retorque the head bolts to 10 ft/lbs.

Re: what the !!#@$$$%*&*&!!

Thanks....I will give it a try.

Re: what the !!#@$$$%*&*&!!

If the seals are bad you could try marinating them with some automatic transmission sealer.

Re: what the !!#@$$$%*&*&!!

also I know this sounds dumb but lube up your throttle cable to make sure it isn't that.

Re: what the !!#@$$$%*&*&!!

Thanks for all of the replies...I rode the moped all weekend because here is the scenario on this thing. I found out through the guy I bought it from that an older couple owned it. He bought it from the woman because her husband died, and she didn't need it any more. They took it on camping trips....but not very many because he died soon after they purchased it. This guy(that I bought it from) bought it with only 150 miles on it, and he put 340 miles on it and decided to park it...for 7 years starting every once in a while. So when I bought it, it had 490 miles on it. The more I ride it the better it gets, so I am hoping it goes away with time. It now has only 527 miles on it and is running much better. This moped is cherry and is very fun to ride. I also bought a red 1982 urban express from the same guy. This one is the one he rode a lot...it has 3,220 miles on it and runs like a top. Take care and thanks again.

Re: what the !!#@$$$%*&*&!!

Sounds like seals to me. We have an old honda three-wheeler that does the same thing when the valve guide seals (its a four stroke, i know) start to leak, it sucks air and oil in through the intake valve guide and leans out the fuel mixture, causing it to rev real high, then kill. i think Don covered it pretty well, look for seals around the intake area.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account