70cc Kstar porting

Hey guys, I am in the process of painting my moped so I decided to pull apart my motor and do a little porting to my Kstar kit, matched with a 15mm bing and proma gp exhaust. I was doing some reasearch and heard that opening up the intake and exhaust port might add a little power, so I decided to do so. On the intake side I took out too much material and went through the ports that are below the intake side. (I dont know what there called) So basically there is a small hole on my intake that shoots into that port rightbelow it. Did I ruin my cylinder?

Re: 70cc Kstar porting

#CrazyWayne™ rocks. #CrazyWayne /

It's a door stopper now, our you can make a porleni out of it.

Re: 70cc Kstar porting

Or a boat anchor if you got one. Any pics of this?

Re: 70cc Kstar porting

Overpriced Parts /

Please post a picture

Re: 70cc Kstar porting

Luke “Funkenet” Hosfield /

Why were you lowering the intake port so much? Even if you didn't go through to the other port, the port timing would make it unusable. Who told you to do that? Even in the other threads people weren't taking several mms off their intake timing only minor 1mm here and there type deals.

Yes we need pics of this one.

Re: 70cc Kstar porting

The blowback is already so much on this cylinder you don't want to mess with intake timing-------------just my own opinion

Re: 70cc Kstar porting

o god! we need pics of this port your talking about! pics!

Re: 70cc Kstar porting

DAMNIT!! I dont know what I was doing. It only had lie 200 miles after break in on the cylinder and the cross hatches from the honing were still very noticeable. I am an idiot I guess. Why wont it work like this? Ill post a pic in a lil..

Re: 70cc Kstar porting

Stupid die grinder...you can see the two little notches going into the two ports under the intake. I read that opening up the intake and exhaust ports will give me more power. I guess not?...

Moped 001.jpg
Moped 002.jpg
Moped 003.jpg

Re: 70cc Kstar porting

Doh!

Re: 70cc Kstar porting

Going wider with them not going down. That sucks man good thing there cheap compared to others

Re: 70cc Kstar porting

wrong way

Re: 70cc Kstar porting

Those ports aren't "below" the intake either they are above it. Those are your boost ports that you ran into.

If you get a new one and decide to port do a little more reading first and don't use a Dremel in my opinion. Get some good quality hand files and spend some time on that shit.

-Aron

Re: 70cc Kstar porting

That wasn't my "finished" product, but hand files sound a little better with that darn soft metal. So the other way huh? I see...anyone want to share any info on what to do with the exhaust ports? The match on the outside with my proma circuit pipe is pretty much the same. Should I pen it up fully round or keep some of the shape it has? Still trying to find an answer for that one...

Re: 70cc Kstar porting

might as well research more, and use that thing for practice on the exhaust side :)

Re: 70cc Kstar porting

you should be getting flamed way more for this.

http://www.mopedarmy.com/wiki/Category:Performance_Tuning

The two links at the top? At least read bell before posting one more time. You never would have done this. All the questions about port shape and bullshit would be answered.

Re: 70cc Kstar porting

Luke “Funkenet” Hosfield /

Try running it. Ya know for science. Your rings prolly will catch though.

Re: 70cc Kstar porting

You could clean up those edges where the boost ports meet the intake so you can have a smooth flow. I don't think the rings will go low enough to cross over the bride, but the edge should be chamfered so it doesn't scratch up the skirt. Then make yourself a little reed block for the intake. Examples of small reeds that might work (honda spree, morini, batavus m48, solo) (edited)

Re: 70cc Kstar porting

Read first? Or reed later?

Re: 70cc Kstar porting

av10 reeds work great as well

Re: 70cc Kstar porting

smooth it out and convert it to a reed cylinder

Re: 70cc Kstar porting

It would be a bit cheaper to turn into a reed kit then to buy a whole new kit? Does treats sell just the cylinder? I just dont know if my skills are up to par yet in creating my own reed kit. Should I go with the Kstar kit if I go that route? Or tccd? Seems as though kstar is a little better?

Re: 70cc Kstar porting

Flame me way more.

Re: 70cc Kstar porting

RADIUM CITY JO$HUA /

Re: 70cc Kstar porting

Yeah I finally got some time to sit down and do some reading. I guess you dont just grab your dremel and widen the shit out of your ports to go faster. Feel like an idiot now...but a smarter idiot atleast.

Re: 70cc Kstar porting

Yep, doorstop. Save the piston as an extra.

Re: 70cc Kstar porting

Yea that cylinder seemingly ruined is a great candidate for more porting with the addition of reeds

Re: 70cc Kstar porting

^This

-Aron

Re: 70cc Kstar porting

Luke “Funkenet” Hosfield /

If you don't want to make a reed kit out of it. I would like to try. How much?

Re: 70cc Kstar porting

The AV10 reeds are the easiest that you can install without a lot of milling machine time. Instead a dremel will work nice. AV10 reeds are small and will only flow a 16mm carb maximum but it still makes for a lot of power if the cylinder and piston are ported for max intake timing. Very easy to tune too. I use that $22 dollar shipped pit bike carb. It has an oval passage through it but all in all its about a 16mm

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account