Intense vibration at high rpm and shudder at slow acceleration.

Status
Not open for further replies.

DanielRocha

New Member
Local time
8:26 PM
Joined
Aug 3, 2022
Messages
1
Hi! My name is Daniel and I recently acquired a 100cc engine kit and as it is my first experience with motorized bikes I have two questions that I would like to have clarified by someone with more expertise and experience.

The first question is: The engine is in the initial softening phase, it still hasn't spent 1 full liter of fuel and I'm noticing, since the first lap, that the engine tends to shake a lot at slower accelerations, as if the engine was braking and accelerating (at the same time) the rear wheel. Is this normal?

The second question is: In more intense accelerations (high rpm), I feel a strong vibration in the whole bike, especially in the handlebars and pedals. Is this also normal?

Thanks in advance to anyone who can respond.
 

Wrench

Well-Known Member
Local time
3:26 PM
Joined
Nov 14, 2018
Messages
5,653
Location
so cal
Probably normal, Engine is nicknamed "Chinese Hand Grenade" :ROFLMAO:

But if everything is aligned properly it might not blow up :ROFLMAO: vibrations will lessen

Main issue might be an unbalanced crankshaft
You can learn how to balance your crankshaft here on the forum

Welcome to your new hobby, trying to make your 2 stroke run well and last a long time
 

DAMIEN1307

Moderator
Staff member
Local time
4:26 PM
Joined
Jul 23, 2020
Messages
6,305
Location
Alamogordo, NM, USA
Thanks in advance to anyone who can respond.

Also be sure that you did not use thick rubber on your motor mounts since this increases vibrations on the bike....Metal to metal is usually best when mounting that motor to the bike frame.

Another cause of vibration is when the rear drive sprocket is not centered well on the rear wheel and the chain has to be aligned properly all the way from the motor to the rear sprocket


Certifique-se também de não usar borracha grossa nos suportes do motor, pois isso aumenta as vibrações na bicicleta.... Metal com metal geralmente é melhor ao montar esse motor no quadro da bicicleta.

Outra causa de vibração é quando a roda dentada traseira não está bem centrada na roda traseira e a corrente tem que ser alinhada corretamente desde o motor até a roda dentada traseira.
 

ImpulseRocket89

Well-Known Member
Local time
5:26 PM
Joined
Apr 16, 2014
Messages
824
Location
Omaha, Nebraska
The real challenge is figuring out what vibration is normal and what isn't. Single cylinder engines by nature are going to create vibrations. As the others pointed out though, there are other things that can also cause them, and some can be a potential safety concern.
 

Axl Myk

Well-Known Member
Local time
6:26 PM
Joined
Jul 11, 2020
Messages
510
I had an 80cc BBR engine from Bikeberry. Vibrated like hell. It was ridiculous.
Pulled it and bought a Ridgeyard kit. 80cc. It ran very smoothly.
Now I have a CDR 80cc iron sleeve engine. Oh yeah, it vibrates, some.
Use a piece of inner tube wrapped around the engine mount points on the bike.
 
Status
Not open for further replies.
Top