An acceptable level of vibration...... By burrhead (Read 1,878 times)

[burrhead]

I have a Jonway YY250T and am nearly finished with all PDI the work......but I have one concern. I know this is a very subjective question but is there an acceptable level of vibration. I have seen post on the trunk rattle and bought and split some 1/4" plastic tubing to run around the lower edge and that pretty much did the trick. But I find at idle the mirrors seem to vibrate more than they should. This is my first scooter so knowing what is acceptable is difficult for me.....would just like some of your thoughts......Thanks.....Dave

[alleyoop]

You will always have a little vibration since it is only one piston but not a heck of lot that the mirrors are moving a lot.

Adjust your fuel ratio mixture to get the smoothest IDLE, the mixture is probably a little off for the motor to run as smooth as possible. after you get the smoothest idle adjusting the mixture then if the IDLE is to high lower the idle USING THE IDLE SPEED SCREW which is on the THROTTLE CABLE SIDE, you will see a screw with a SPRING on it. Turning that CLOCKWISE raises the IDLE Counter Clockwise lowers the IDLE. The IDLE should be around 1800-2000 on the 250s and the REAR WHEEL should not be spinning, maybe just wanting to turn.
Alleyoop

[burrhead]

OK.....will do that.....thanks

[Barnie]

Burrhead, follow Alley' suggestions for good smoothe idle. I have a MP250a and I get some vibs in mirrors etc but soon a I touch the throttle is is glass smoothe at all speeds, I can still see out my mirrors at idle. Hope this helps u. Barnie

[ellpee]

My idle was too low from the factory, but I only had to raise it to around 900 to get good starts and smooth idle. Upping it to 1800, at least on MY scoot, would be way more than I need.

About trunk rattles, I was one of the ones griping about that, and yesterday I finally found a good fix. I had previously put rubber tubing all around the lower edge of the trunk lid; that considerably reduced the rattling, but there was still enough to be annoying. The main remaining rattle source was the third mounting point for the rack where the trunk mounts; the rear plastic and metal were vibrating against each other. I removed the rack, three bolts, and on the bracket for the third (rearmost) one, I cut two pieces of foam packing material -- not the stiff styrofoam, the spongy kind. I worked one piece in underneath the plastic, and another, thinner one on top of the plastic, around the protruding bracket, then reinstalled the rack. Voila, no more rattle AT ALL!

[burrhead]

Thanks everyone.....one more question(yea right!)......is there a proper sequence to removing the plastics? Or does it matter?

[ellpee]

Yes:

(1) Hire somebody
(2) Let him do it



Sorry, couldn't resist. Removing plastic is my worst nightmare, even though it's not really HARD, just tedious and annoying. I've already had to deal with mending three broken tabs where screws are supposed to go, other tabs that never fit together as well as they did originally, mending a crack in the bottom of the trunk from a combination of tight bolt and vibration, yadda yadda yadda.

I first "attacked the plastic" at the front end because I needed to check a bunch of electrical stuff. Windshield and associated parts, not too bad. Plastic on handle bars and top of dash, not too bad. Main plastic that forms the fenders, headlight cowl, etc., removed every screw and bolt I could find, NEVER COULD get the plastic off, and had a LOT of trouble getting it all back in place and aligned as well as it had been. (Managed to get the needed electrical work done by worming my arm through the openings I had created, leaving a little skin along the way.)

Next plastic event was getting at the R/R, which involved both upper panels at the rear, under the seat more or less. Removed all screws and bolts, got them loosened enough to move them up and out of my way, though I never got the two panels completely off because they are held together somehow by the taillight assembly and associated plastic. Never mind, that was good enough for what I needed to do, but when I put everything back, the pieces didn't fit together quite as "seamlessly" as before. Good enough for me, but far from perfect. They're not flapping in the wind, won't fall off somewhere out on the road, but less than ideal from a cosmetic standpoint.

So I can't give any advice on a proper sequence, only lots of anecdotal evidence that it's a major PITA. On the other hand, others have posted that it's not that big a deal, so maybe I'm inept, picky, or both.

BTW, I found removing the seat to be a particular pain. Three nuts involved, in a location where an open-end wrench and one 30-degree turn at a time are required, that x three nuts. No way I could see to get a socket on it and use a ratchet, just not enough room. Definitely a three-Budweiser project. And, since I removed mine, the latch alignment is a wee bit off, making closing/locking the seat compartment a minor annoyance. That can no doubt be adjusted for, just haven't gotten around to it yet.

[burrhead]

Thanks ellpee.....the level of confidence you have instilled in me after reading your post is at an all time high! . Seems like almost all mechanical operations on this scoot are laid out in full detail.....some even with videos. Why not one for removal and reassembly of plastics?

[cruiser]

May 14, 2013 8:53:12 GMT -6 burrhead said:

Thanks everyone.....one more question(yea right!)......is there a proper sequence to removing the plastics? Or does it matter?

The body of your scoot is identical to the Honda Reflex. Use section 2 of the service manual:

.jr-richscooterdoc.com/Honda-NSS250-Reflex-2001-07.pdf" rel="nofollow" target="_blank">.jr-richscooterdoc.com/Honda-NSS250-Reflex-2001-07.pdf

Don't be too discouraged if you are not able to get to the idle mixture adjustment screw. It's almost impossible while the scoot is running. I think you have to twist the carb on its side to see the screw. If the scoot is idling too low, it will shake the mirrors. Try adjusting the idle speed screw for about 1700 to 1800 rpms when warmed up.

[burrhead]

That's a big help......thanks so much!

[ellpee]

Seems like almost all mechanical operations on this scoot are laid out in full detail.....some even with videos. Why not one for removal and reassembly of plastics?

YOU TOO can be the first in your neighborhood to achieve film stardom by recording the whole process as you suffer through it ....

[burrhead]

OK.....so where is the idle adjustment screw on. YY250T and does that also require removing plastic? I know it's on the carb but what's my angle of attack? And yes I will film the misery!

[gatekeeper]

Open the seat. There is a should be an access panel in the bottom of the storage compartment, a couple of screws and take it off. The idle adjust screw is on top on one side of the carb near the wheel the end of the throttle cable attaches to.

The air/fuel adjustment screw is on the bottom of the carb on the intake manifold side. Much harder to get to.

[richardthescooter3]

I also have a vibration problem with my intakes working loose because the carb is not mounted to anything, I need to find a way to bolt this carb down, it seats right on the piece of frame going under carb. I've put loctite on the threads and a lock washer, (it still works loose).

[richardthescooter3]

HERE IS PIC OF CARB

Attachments: