Weird pulse or vibration By icebear2009 (Read 1,447 times)

[icebear2009]

OK I have a 150cc scooter and every time I use my left side brake handle I get a weird like pulse or vibration coming from the motor I can feel it when sitting on the scooter ....any ideals

[Alleyoop]

Check you idle it may be to high and braking the rear is putting a load on the motor.

ON the centerstand your rear wheel SHOULD NOT SPIN, if it does lower the idle to where it stops spinning.

[mrgigabyte]

alley this is mrgigabytes scooter we are speaking of its not that kind of feeling its almost like a vibration type feeling not like a surge in idle at all like the motor feels ruff and its the rear brake by the way when i do it with the front brake i dont feel it

like to add that we did do a iridium plug a performance cdi and the performance coil you think something there doing it ? couldnt really say if it was doing that before any upgrades because it seems to run a little bit ruff at idle but nothing terrible

[cyborg]

Disc or drum brake? Drum brake out of round? Disc warped? That's my call,,,especially if it's only with the rear brake

[Alleyoop]

Is this Vibration at a stop or as your braking to stop?

IF at a stop then:
If the idle is to high you will get that through the motor the motor is being loaded down if the idle is to high it wants to turn the rear wheel.

Well if its one of your orange performance CDI's it has the timing advanced from the get go. Also with the Performance CDI, Iridium plug and coil you would need to tweak the carb some because that all would change the way your motor runs. Maybe the CDI is advanced to much don't forget all these are from china not much qualaity control (HAHA).

[icebear2009]

Yes one of the orange ones ? So what u recommend then and yes its when the bike is ideling I don't even have to move to feel it

[Alleyoop]

On the center stand does the rear wheel spin some, IF NOT I would put the OEM CDI back in and see if that tames the motor down.
Alleyoop

[icebear2009]

I'm not to sure ill have to double check

[icebear2009]

I did mine with the same stuff and it all seems fine

[Alleyoop]

All motors are not the same and all cdi's are not the same. Also the rear wheel spin on the center stand once the motor is warmed up?

[icebear2009]

OK ill have to double check it all I do u recommend a/f screw adjustment if do ? Also did gear oil change on both of their scooters and would only hold 4 ozs and that was after warming up motor and draining all old out and the both gave the 157qmj motors Like us why only 4 ozs and not 8?

[Alleyoop]

Before you go and adjust anything try just swapping out the CDI with the OEM. The advanced CDI's and Iridium plugs cause higher rpms.

But you NEED to tell me if the rear wheel spins at idle on the centerstand???

[icebear2009]

OK alley checked scooter to see if wheel is spinning at all on center stand and nothing at all ....what u thinking

[Alleyoop]

Ok, so it is not that the idle is to high maybe it is to low to low will also cause to much vibrations from the motor. What rpms does it idle at, it should idle 1500-1800 where ever it idles the smoothest without the rear wheel spinning.
If all that is good then swap out the performance cdi and plug in the Original and see if that tames the motor. If it still does it NOW you can adjust the Fuel Ratio Mixture to get the highest idle out of the adjustment.
Alleyoop

[icebear2009]

His bike does not have a rpm gauge but sounds about 15-18 its nice and smoothe its just a weird feeling when pushing brake handle ...if you push just a little no feeling if u push slot u can feel it and this is all at a stand still