Resurrecting a 2006 NST 50cc By gatekeeper (Read 3,686 times)

[gatekeeper]

Picked up a CL special the other day, a 2006 NST MPS50. The ad said it had 3000 miles on it, ran good but it would not go and he wanted $250.00 for it. I went and looked at it. It had some scratches on it but looked pretty good body wise and it did sound good while running and was easy to start. When throttle was applied, nothing at the rear wheel. I spun the rear wheel both ways and could hear nothing unusual and the gearing seemed to feel smooth. Thanks to some of you hear I was 98% certain that it was just the belt.

Hanging my head, I talked to him for a while and got him to lower the price to $175.00. When I got it home and opened up the CVT case what was left of the belt fell to the floor. I had to take the clutch apart and clean all of the little pieces of belt out of it but the clutch side all looks good. On the variator side I found one of the guide (glide) clips broken in half and a couple of the rollers were starting to get a little flat spot on them. Other than that all seems to be in good shape.

I've got a belt, a complete variator assembly (found the variator on Ebay for $17.00 shipped) and new battery on order. Until they get here I will clean the carb, change oils and fuel lines/filter. The lines and filter look to be OEM from the far east.

Again, thanks to a lot of you I felt confident and knew what to look for.

Attachments:

[JR]

Great find! While you're waiting on your stuff you might just want to give it the good old going over and here is some help:

thescooterprofessor.proboards.com/index.cgi?board=general&action=display&thread=33

Like I've been saying I'm getting more help files in and soon the rest of the manuals but if you need anything before I get them all in just holler and I'll find it!

JR

[gatekeeper]

Hey JR, thanks for the link. I'll be getting on it tomorrow.

[gatekeeper]

OK, so far I've put in a new variator and belt. Pulled the clutch out and cleaned all of the old belt pieces out of it. Clutch looks good. Checked Changed the oil, both crankcase and final drive. Replaced the fuel lines and fuel filter. Pulled and cleaned the carb. Idle jet was partially blocked. Checked all fasteners for tightness.

Checked the electrical connections. and found one black/white wire under the nose that was disconnected. Figured out that was why the engine wouldn't shut off with the key so that works now. Both filaments in the headlight bulb are blown so I have one on order from Scrappy. (Along with a new plug) I checked the voltage at the headlight socket to make sure it has proper voltage to avoid blowing the bulb and it checked out good. On the AC scale it read a little over 11 volts at idle and a little over 12 volts as the rpm's were increased.

I still need to check and adjust the valves as it seems to run good but is hard to start when cold. The enricher seems to be working as when it does finally start it runs at a higher idle for the first minute or so then slows down to a steady lower idle.

Now for a question: Two days ago I checked the charging voltage at the battery. (On the DC scale) I read 16 to 16.5 volts. (Didn't really matter what the engine speed was) Today when I checked it again, (still on the DC scale) it read 12.5 at idle and 13.5 when rpm's were increased. Now to me, the second test seemed normal. Any ideas why it tested higher two days ago but not today?

[cruiser]

Believe it or not, both charging conditions are more or less normal for a Chinese 50cc scoot. The higher voltage condition is what will happen as the battery reaches full charge. In this case the R/R allows over charging instead of reducing the charging voltage. The second case shows a battery which is not fully charged and the voltage is drawn down while the heavier charging current is drawn into the battery. As the battery charges, the voltage will eventually reach the higher values you saw earlier.

In other words, the R/R does not regulate very well and that seems to be the norm for most of these scoots.

[gatekeeper]

Thank you Cruiser. Now that I think about it that does make sense to me. Today I had to crank it quite a bit to get it started and then took the reading fairly soon after it started. Two days ago when I took the reading it had been running for quite a while as I was adjusting the carb and generally playing around before I took the reading.

Now why didn't I think of that?!?!

[cruiser]

You are welcome, grasshopper, I mean gatekeeper. As you progress through the educational offerings of U-Scoot you will in time develop your mental acumen. Seriously though, my VIP50 does the same thing as your NST.

[alleyoop]

Got to say you got a great deal, and with a little TLC which you are giving it you have a nice running scoot on the CHEAP.
GREAT FIND BRO!
Alleyoop

[gatekeeper]

Thanks Alley! I'm considering this one as my "class" project.