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Discussion Starter · #1 · (Edited)
EDIT: (Totally rewrote this)

Alright so wanting to learn as much as possible about these things, and to get over being timid when it comes to modifications like this, i want to attempt to port my own cylinder.

I saw a post about which bits to get for the dremel, which i will pick up, and i also need a file set. Both of which i will invest in coming up, and i am in no way in a hurry with this project. When ripping the head off of my crank, the top of the piston has some build up of im assuming old gas/oil mixture. Extremely tough on there, but if i soak the tip of the piston in seafoam, id expect it to come off like nothing.

I've also read as much as i can and seen as many pictures as i can on this subject, so I have an idea where and what to do, but with every first time, im still scared. I surely do not want to screw this up, but ****, thats how we learn, right?

Anyways, i just want to get the basics down, so i really dont wanna butch the head too much, but i would like to smooth some things out and polish them.

Again, since my head is completely stock, from what i can see, i kinda know what to do, but i would like some advice on what extremities to take it to.

I will be posting some pictures following this edit to illustrate what im working with.

Thanks for your time guys and i look forward to reading and learning from this.

This will not happen over night, and i will not start it until im 100% ready with the tools and such.
 

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Discussion Starter · #8 ·
Couldnt get it to start. Had what seemed like low compression, cleaned the carb, which wasnt dirty, swapped for my other stock clean carb, disconnected every single wire, switched plugs, which has spark, but weak one. Going to clean up the coil next and try that. But wanted to pull the head to check the rings to be honest, and see how the top of the head looked. Everything checks out, so i wanted to attempt to port it, but a friend of mine who has modded a couple gopeds suggests i get the **** thing running first.

Good idea, so imma get a gasket set, clean the **** up and get all the grease off, then button her back together and attempt to start it.
 

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Couldnt get it to start. Had what seemed like low compression, cleaned the carb, which wasnt dirty, swapped for my other stock clean carb, disconnected every single wire, switched plugs, which has spark, but weak one. Going to clean up the coil next and try that. But wanted to pull the head to check the rings to be honest, and see how the top of the head looked. Everything checks out, so i wanted to attempt to port it, but a friend of mine who has modded a couple gopeds suggests i get the **** thing running first.

Good idea, so imma get a gasket set, clean the **** up and get all the grease off, then button her back together and attempt to start it.
if you got it open it wont hurt to add 4 windows to the piston,,deburr the edges and raise the sideskirt profile a tad,,widen the intake and exhaust 1/8" on each side and reinstall without a basegasket to raise compression..

Your startup problem sounds like a faulty coil............
 

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Discussion Starter · #10 ·
The coil was greased up beyond belief, which hassss to have something to do with it. The grey plastic cover serves a purpose, but i dont like how it encloses everything which will allow for gunk build up.

Thanks for your expertise cam. I wanna do all of that, and the windows to the pistons worries me the most. How would i do that 100% precisely?
 

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Discussion Starter · #12 · (Edited)
I'm guessing that u didn't get the other engine back?and did ur parts come for ur x12?
sam is still working on my other one, seriously not concerned with that one. That can come back whenever he is ready because that one will be ready to run. Excited? Definitely, but good things come to those who wait

And yes for the x12, i got the throttle cable, which is ready to be put on, cleaned the carb totally out, all jets and everything. Old, but the carb should still function 100%. I however recieved the wrong shock, so 2 nights ago i ordered the correct one, (750lb/s yikes, i know sorry. but ill swap springs from my stock one) and now im waiting for that in order to have a 'rolling bike'. Once thats here, i have a solution to the kick start (bale wire from work, gonna drill and put that through as a pin) and ill change the fluids, hook the intake and carb up and hopefully be good to roll.

Question to everyone. Boost bottle on 4stroke? Beneficial?
 

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You should get your engine from Sam pretty soon, wait till you see the difference from the stock ports. I still clean it up real good, no sharp edges, smooth and shiny, that's the ticket. Get some Yamabond, from Yamaha Dealer or Honda & hondabond. Clean the gasket away, and a thin layer of it with your finger, no beads. Don't waste your time with a boost bottle for a 4 stroke
 

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Discussion Starter · #18 ·
if you got it open it wont hurt to add 4 windows to the piston,,deburr the edges and raise the sideskirt profile a tad,,widen the intake and exhaust 1/8" on each side and reinstall without a basegasket to raise compression..

Your startup problem sounds like a faulty coil............
What do you go off of when adding windows to pistons? Try to match what yours usually look like yeah, but I don't wanna damage the integrity of the piston to a point where it send a piece of metal through the crank lol
 

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What do you go off of when adding windows to pistons? Try to match what yours usually look like yeah, but I don't wanna damage the integrity of the piston to a point where it send a piece of metal through the crank lol
You keep the windows inside the width of the transfer ports on the sides....If you put the 7/64" holes where I put mine then youll be ok,,,,any higher and youll be in the ring lands and any lower and youll be drilling through the beefy part of the pin journal which will slow flow and render the mod pretty well useless..When pistioned properly itll drill through perfectly in the right spot.............

See the two humps in the sideskirt under the pin on both sides...?..Those need to be grinded in aswell....



This is a 40mm 43cc piston

 

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Discussion Starter · #20 ·
Both are drilled at an angle it seems? And these holes are the windows..? Seems aloeasier then the windows I'm imagining. Sorry for the confusion, perhaps I have more to read first
 
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