86 NB50 first performance upgrades

[fatcharlie]

Hello all,

I'm brand new to the scooter thing and picked up an 86 NB50 to play around on. Id like to look into picking up a few MPH on the top end. (I'm pulling 35ish indicated on the speedo on the flats). Ideally, i'd like to see in the mid 40s.

I'm looking into doing a Ruckus Variator to start with. - Question: What weights should I start tuning with?

I've read that an 85 main jet on a stock NB50 is a good way to go... I'll likely be moving to that.


Any other cheap upgrades for right now? How about drilling out the airbox? Can I open up the exhaust at all?

Thanks in advance, I have experience with motors and tuning, I'm just new to scooter specifics.

[Wheelman-111]

Greetings:

Welcome Charlie.
The Ruckus variator is a good choice. That and a 90/90 rear tire will have the effect of making the overall gearing taller, and may be good for a couple of MPH. Remember that adding gear doesn't necessarily add speed. The Power has to be there to take advantage of the longer legs. (See below)

Stock NB rollers should be 10 grams. Dropping the grease cover and switching to the bigger diameter Ruck vario is a good start already. So is replacing rollers that are probably flat-spotted. I suggest you seek some 8.5s and 9-gram rollers to install in the new vario. Trial-and-error, and you can mix and match 3 of each.

Drilling the air box carefully can open up a little more flow, but only if the engine demands it. If the box's intake restriction was not the Limiting Factor, it won't help performance much if any. There's even a chance that the reduction in the negative pressure upstream will cause the Pilot circuit to go too lean. If your jetting is correct for your engine now, an 85 jet will make it too rich. If you do drill the box, then maybe it's safer to start with the 85. I have no confidence in predicting improved power from those mods alone. It might even decrease.

Same for the pipe. There's little to do to improve performance there. Drilling baffles usually only makes more noise.

If 45 is your goal, a healthy Aero 50 may only get you close. The Next Step is the lip of a Slippery Slope. Big-Bore kit with all the accoutrements can get over 55, but the cash/MPH ratio goes WAY up. If you can live with 42, you could already be there.

[Bear45-70]

The 85 jet is a know performance enhancer because Honda was big on running a step or two too lean to make the EPA happy and trying to improve mpg.

[fatcharlie]

Stock NB rollers should be 10 grams. Dropping the grease cover and switching to the bigger diameter Ruck vario is a good start already. So is replacing rollers that are probably flat-spotted. I suggest you seek some 8.5s and 9-gram rollers to install in the new vario. Trial-and-error, and you can mix and match 3 of each.

You mention removing the grease cover. Is that the portion of the variator attached with the 3 screws? So basically I would have the main part with the rollers, plate and bushings installed in the bike?

[eliteguy50]

Stock NB rollers should be 10 grams. Dropping the grease cover and switching to the bigger diameter Ruck vario is a good start already. So is replacing rollers that are probably flat-spotted. I suggest you seek some 8.5s and 9-gram rollers to install in the new vario. Trial-and-error, and you can mix and match 3 of each.

You mention removing the grease cover. Is that the portion of the variator attached with the 3 screws? So basically I would have the main part with the rollers, plate and bushings installed in the bike?

Correct.