Engine Trouble Balance

[Eddie Medley]

I was wondering that with all the perfoermsnce part you can get for your 80cc 2 stroke engine do you really need a balance crank for it or will it be fine with stock balance crank.

 

[Deleted member 12676]

if it vibrates now then it will vibrate even more at higher RPM which it will do if you modify the engine.
But some new engines aren't too bad. And others are absolutely horrible.

 

[Eddie Medley]

Ok thanks, so I just got to get lucky with an engine for less vibrations.

 

[Deleted member 12676]

recently someone mentioned that a certain engine was almost vibration free but I don't remember which one that is.
Hopefully someone will jump in here with some good info.

 

[zippinaround]

i recently conducted your spoke test on my 48cc , it barely vibrated at max but around 6k (at a guess) there was minor vibration , and also on reving down but for slightly longer .

i now have said engine apart in bits and the crank wheels on skinny edge are very rough almost like a sharp thread (one wheel is very sharp the other notsomuch) theres 3 phillips screws in the wheels and the holes are filled with some white stuff , no other holes other than where the conrod connects

 

[Deleted member 12676]

My Suzuki doesn't vibrate at all at max RPM. Only around 3000 it vibrates some. This is the way all 2 strokes should be.
You can use my spreadsheet to figure out what size holes to drill in the crank wheels for better balance.
click on my signature link

 

[zippinaround]

was looking earlier couldnt find the specific crank balancing bit but i think i tried it before and couldnt make sense of it.

 

[Deleted member 12676]

did you watch my video about it?