Getting my cylinder bored out.

[Arctic Wolf]

Im getting my cylinder bored out .50 on my 50cc motor tomorrow. Im just wondering what my new cc would be?? I read a good article on this a few weeks back but cant seem to find it anymore. Is there anyone out there that could possibly help??
Id go for a big bore kit.... But when I bought the bike it already had one and the guy didnt put the clip in proper. So needless to say there went the piston. You know the saying. Once bitten Twice shy... I wont go with another one for a while. Instead Im going to play with it for a lil bit and see where I end up.

[Kenny_McCormic]

If you are boring it for power there isnt any to be had doing that, you bore em out when they get too worn to use standard size pistons in em. You are only getting a whole matchbook covers worth of bore.

[Arctic Wolf]

Yeah but I know that I saw something on this matter. I know it didnt raise the cc's much but it did raise the cc's non the less. So what would me new cc's be?? 52?? 55?? Its gota be something

[Kenny_McCormic]

I doubt its over 51, any gain in power will be lost throwing the huge piston around on the now too light crank. Balance is everything.

[Wheelman-111]

Greetings:

Now don't you wish you'd payed attention in Geometry class?

A 0.5mm bore-out on an SE50 (AF05) nets you 50.5cc.

A 0.5 bore-out on an AF16 (Dio SA50) gives you just a bit more. -50.7cc.

Look up the bore and stroke specs of your model, add the 0.5 mm diameter of the new bore and plug in the numbers.

[Arctic Wolf]

Thank You Wheelman. Thats what I was looking for... It was that simple.. Not all the Jargin about performance.

[Towlieee]

I don't know scooters, I do'nt know 2 strokes..

But generally, a 'next size up' bore is .02 over, not .2, not .5, .02!!

It's not about making more power, it's about getting fresh cylinder surface so your rings can seal




On a side note, how much you spending on this bore and piston? Have you looked into big bores? You could go 70cc+ for as cheap as $130++

[Kenny_McCormic]

.5mm is just short of .020"

[Towlieee]

.5mm is just short of .020"

ahhhh I'm a retard, I was thinking they were saying .5"

that's what I get for opening my mouth instead of reading more

[Lunytune]

I don't know what kind of prices you are looking at for bore, new piston and rings, but I tried that route and was quoted "around" $200. The HondaCharlie delayed a month, so I cancelled him out, and bought a kit on eBay for $165 plus shipping. My local Honda man was talking in terms of "one over" and "two over", meaning one millimeter and two millimeter. He didn't talk inches. My overbore kit was 6 over (equivalent to 243 caliber bullet), putting it up to about 72cc displacement. I'm not sure about a 1/2 millimeter, or even if there is a piston and ring that size. That's not much more than honing. For the cost involved, I'd go with the overbore kit.

[maddog]

its .060 or one over, yes i bought several polini 72cc kits yrs. ago for $90 no they are not for sale, yes my moderator days are comming

[Kenny_McCormic]

its .060 or one over, yes i bought several polini 72cc kits yrs. ago for $90 no they are not for sale, yes my moderator days are comming

1 millimeter = 0.0393700787 inches, nowhere near .060, no your mod days are not coming XD

[Lunytune]

its .060 or one over, yes i bought several polini 72cc kits yrs. ago for $90 no they are not for sale, yes my moderator days are comming

1 millimeter = 0.0393700787 inches, nowhere near .060, no your mod days are not coming XD

You mean understanding metrics is all that's required to be a mod? Then sign me up. I thought what was required was knowing the firing order on all Sprees and Elites. I've been tinkering with metrics in old military rifles so long I've got 'em mesmerized. That's how I knew the Polini kit was just under 1/4" overbore. Been crunching the numbers, but just last night bid on a set of metric calipers so I won't have to anymore. My brain doesn't function like it used to.