Vibration By blu (Read 835 times)

[blu]

For a while now I've been getting quite a bit of vibration from the engine.  It wasn't always like that.  I pulled the plug and it had burnt to about a .050 gap.  I replaced it with a new one, but it didn't change anything.  What could cause these little 250cc engines to vibrate abnormally??  

[cyborg]

Motor mounts going bad,,, internal parts not spun balanced,,, there's a bunch more things,,, tires not wearing smoothly or evenly,,, warped brake disc or drum out of round

[arskal]

Hi.

Check rear shock absorbers and mounting bushes if they are worned. Check center stand bolts if they are loosened.

[gorj]

Is it a vibration when moving down the road from the drive train (front or rear) or is it a vibration coming from the engine, like when on the center stand and revved up? Do you feel it in the had grips or do you feel it in your butt?

[blu]

I think it's just normal. My trunk lid started vibrating and it just made me pay attention. I put a little cushion under the lid and quieted that, I think it's just the nature of a single cylinder 250cc that I'm feeling. Everything seems to be fine.

[2stroked]

From experience, the horizontal 257c Linhia clones tend to have more vibrations than the vertical 250 Hondas and Clones.

[jct842]

And a straight up 90 degree engine should last longer being better balanced. The weight of the yami clone piston sliding along the flat cyl surface is the killer.

[jct842]

And a straight up 90 degree engine should last longer being better balanced. The weight of the yami clone piston sliding along the flat cyl surface is the killer.

[2stroked]

Yup. Very true. My Helix though 30+years old with over 100k miles still starts runs rides and idles beautiful.
Wonder what's going to happen with the Linhai clones in twenty some years when they are over thirty?

[gorj]

Flat engines do not wear any faster than vertical engines. Consider the BMW motorcycle, the Subaru, the VW air cooled, and many small airplane engines. Longevity has more to do with the quality of the build than if the piston goes north and south or east and west!

[2stroked]

Quality of build and quality of maintainance. It doesn't matter what you have, if you use and abuse it, and do not maintain it will not last.
I have always believed that a well maintained Chinese scooter could last almost as long as a big brand.

[arskal]

Hi.

I think I found reason for my Jonway 250c (15500km on it) engine vibration and little knocking in low rpm, about 3500-3800rpm. Listen this video Jonway 250cc knocking. I think connecting rod cause this knocking. Otherwise the engine will run smoothly in higer rpm.
I changed engine oil regulary, every 1000km. I used synthetic oil 5W-40 every time. Is that oil too thin. Should I use 10W-30 mineral oil?

- Arska -

[cyborg]

I use 20-50,,,with 20% Lucas oil stabilizer,,,cause it gets god awful hot here in SoCal