Honda Urban Express big bore jetting...

Does your Spree/Elite already run great, and you're trying to make it quicker/faster? Need a monster motor swap? Discuss your ideas here.

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mhardgrove
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Honda Urban Express big bore jetting...

Post by mhardgrove »

Rebuilding a 1982 NU50 Urban Express. I installed a 70cc kit with corresponding head. IÔÇÖm going to need to change out my jetting as IÔÇÖm planning to run a MLM sidebleed pipe from treatland and a pod filter with the stock carb. Asked about the jetting on moped army and IÔÇÖm getting all sorts of wild answers all over the board, all from non Honda owners. IÔÇÖm new to 2 strokes, is there anything I need to replace like the reed (it appears fine)? IÔÇÖm also going to run premix and IÔÇÖm in Denver. Simply looking to get my 260lbs to 30mph without getting creamed, thus the 70cc upgrade.

Seeing that the spree uses a similar engine, is 90 to 93 on the jet a decent range? If not what would be good? Also, what would be a nice and safe range for the premix?
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motormike
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Re: Honda Urban Express big bore jetting...

Post by motormike »

Like what you're doing... :geekdance:
Should be getting you a tad bit over 30mph once tuned.
Can't share any technical advice for jetting...but with a triple
whammy of pod, pipe, & bore kit, seems to me an intake and carb are inline.
I'm like you though, I'd try jetting the OEM carb first.
Good luck with it... :urban:
Last Urban I had was pristine, but the seat and I had a few arguments,
and I let her go. The "tool" that bought it from me for $550
went home and listed it on Craigs for $1200...whatevs... :roll:
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harleyracer59
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Re: Honda Urban Express big bore jetting...

Post by harleyracer59 »

id say jump atleast 10. if its a 70 go 80. you still might need to go higher. id rather start a new barrel richer than leaner
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Wheelman-111
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Re: Honda Urban Express big bore jetting...

Post by Wheelman-111 »

Greetings:

I agree with HR IF the bike was a local Mile-High machine to begin with. However jet numbers from Florida and coastal states won't work at 5000 feet, or at least not very well. Not much Oh-Too up there.
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