If you drill it with a hand drill, just step up the bit sizes instead of doing it in one go. Takes longer, but goes much smoother and you are less likely to burn up the bit.

And what about a YD100? Same exact thing? Because they're all not the same. Different weights.

Super nice work my friend! 👍

helps to be a competent machinist like these guys, right? what about all the other problems w/the cranks; wobbley, out of true, etc? prolly the crummiest part on these motors is the abysmal stock crankshafts, right? i mean-how often do you get one that is put together right?

Is this Ballance good for a Stihl head that has high rpm or do you recommend taking more off

I have a ld100 and I’ve ordered a Reed valve and windowed piston would you still recommend this?

I’ve also seen them do the 7/16 on both sides left n right 5mm deep as well idk the difference tho so…..

Is this for the 80/66 cc engine ?

Nice work! Hey I had a very important question, I bought a used bottom end and I've had to do lots of things. The recent one being I had to split the case because of a leaking case gasket. I noticed that I have what appears to be a balanced crank, yae! The rod is an AF80. I was using a 49mm iron sleeve, but I was thinking I would have better balance if I used the regular 47mm piston, and use my G4 cylinder. I'm not yet hip to balance factors, but I was wondering if these balance techniques are primarily used for the normal bores size and pistons? Also it appears that the case was ported for a minarelli jug. I haven't ventured into that arena either, lol. Any help with your knowledge would greatly be appreciated, thank you. ☺️

Do you sell them?

It’s 4 wholes 2 each side front n back or only two? I have 80cc chinadoll n I when I get to 30 she does get a bit vibratey

Hello I have only have a 3/8 bit can i drill two holes?

Will lighten the crank by drilling a small 3/16(etc.) at set intervals cause too much offset in vibration or increase the overall r.p.m. factor? Just curious if you have looked at that as an option? Thanks for sharing the information.

Damn it's very hard to hand drill, dtm I know have a drill press but they don't believe in drilling the crank so they didn't service my crank 😔.

what is the drill bit size in metric units. also does this work on any motorized bike engine?

so you don’t drill all the way through?

Acording to my calculation it should be somethink around 15g each hole so around 30g total, but shis is just calculated based on normal steel, I dont know the exact density of the chinese steel.

Ok so if I mod my engine and it vivrates like no tomorrow. I can drill holes as such as you've done here an it will help or make.it smoother completely. Great informative video by the way Thanks for sharing

I have a crazy issue. Been working on a 50cc bike engine. It's been a disaster from the word go. What is the normal width of a 50cc crank From outside of bearing to outside of bearing? Mine measures 2.165". The problem being that the inside of the crankcase is only 2" give or take a few thousandths. There's no way in hell this will work. It had two thick gaskets on it when I got it and was a witch to turn, duh. So which part is wrong so I know which one to replace?

How do you know how much weight to shave?

Yes it's just that simple. Its not really a high tech job to balance china doll. Thanks

my bicycle engines crank 15.77mm thick, do I still go 15mm deep?

What about a 52 mm? I have a phantom

The perfect balance in a crank?? Definitely not! This actually can be done perfectly, but something called maths is required.