Y does my nu50 go 27 mph

Ok so I've cleaned my carburetor, fuel filter and fuel lines and gutted my muffler why does my NU50 still only goes 27mph?? It bogs out when it reaches 27mph. any help??

Re: Y does my nu50 go 27 mph

How much do you weigh? Thats just about how fast they go. Maybe variator issues? Maybe its lean? Do any plug chops? are you in Iowa? Is it an Iowa express?

Re: Y does my nu50 go 27 mph

Belt worn? Iowa model? Wrong jetting? Low tires? Dragging brakes? Dirty/stuck variator? Fat ass?

Re: Y does my nu50 go 27 mph

I just put new spark plugs in it. I just got done testing the jetting moved the needle up to 5 and 4. it stopped bogging now it dies every couple of blocks. I have to wait a few minutes then it will starts back up again. I'm driving it with out the air filter box to does that matter? I weigh 188 pounds it's not an Iowa one. Belt I have no Idea about back tire is a little low though not by much. Does that make a big difference?

Re: Y does my nu50 go 27 mph

Meh, maybe a little. The no air box is where your issue is, I reckin. You weigh like 15 more lbs than me, so thats maybe 1mph difference, tops. Heres what you do. Measure the outter diameter of the mouth of your carb, where the air filter would be. Go to your local motor sports shop, and get a uni filter with the closest diameter to what you measured. I wanna say its like 1 3/4 inches, but maybe not, just measure. Any way, ask them for a uni pod with that measurement for an inner diameter on the flange. Throw that on there and you should be good. Now the dying every couple of blocks could be a couple things, It could be a soft seize from running too lean. More likely, its a fuel flow to carb issue. Yank your fuel like off the petcock up under the tank, and see how fast the fuel runs. If its just a slow dribble, blow some compressed air through there. If its running good, then maybe its something to do with your check valve. The other option is it might be electrical, the whole shutting off thing. Unfortunetly, electrical problems are the paper to my mechanical skills rock, so I can't help you if thats the issue.

Also to be considered is the fact that some bikes just aren't as fast as others. I donno why, but most bikes run about 29mph +/- 2-3 mph stock. Some guys say a good running urban does about 32, so maybe if you fix your mixture that will do it, otherwise you can buy a pipe for it off of treats if you want like 4 or 5 more mph.

Re: Y does my nu50 go 27 mph

Ok i have the box for it should i put it back on or use your method for the air box. last summer after it was warmed up it got 30 mph or so though not this year.

Sorry it dies when I stop does that matter?

the thing ran fine before i played with the needle.

I also took off the head to check for carbon build up. I made sure that it went back just the way i took it off. and clean...

? any other suggestions


ks for the advice

Re: Y does my nu50 go 27 mph

thats as fast as they go

Re: Y does my nu50 go 27 mph

new belt , if you can find one, gave me almost +5mph from 27 to 32. about the stalling, put needle back where it was running good, replace stock airbox, hows the foam filter in there? ever clean the autochoke box? gas tank full?

Re: Y does my nu50 go 27 mph

Where did you get your belt Chris? Was it you or someone else who posted a vendor a while back.

Re: Y does my nu50 go 27 mph

yeah, that was me.


call them and talk to vintage honda parts guy. who knows how many are actually still around, you may have to try other honda places from the shop links wiki.

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