I am looking to get going on my build. I am open to input on it but have a pretty good idea what I want to do. My first question is with a stock clone block what is the most you can reasonably bore it? I am seeing like .01" and .02" but nothing really more than that. I would think that with only that amount there would be very little power gain. Maybe I am wrong but I would think you could bore it more than that. My next move will be a flat top piston and deck the block. My head is in the process of being machined .065" and ported an polished. I also definitely plan on upgrading the valves and carb. What would be a reccommendation on carb size? I was just gonna get a tilly and not really sure what would be the ideal size. Another thing I am not to sure about is what size cam would see the best gains with this setup?

what are you trying to do with this engine is the question?

what is it gonna be used for ?

your going to have to measure the OD of the sleeve to see how big you can bore it, being the sleeves vary from block to block.

like i said though it will be pretty much impossible to measure the thickness as it is covered at the bottom with the casting. and its really gonna be used for fun....taking it out to the track to mess around with no serious competing.

It is covered with the casting? That's strange. You have to measure the sleeve at the bottom to see what will fit. If you can not measure it, for whatever reason, then it is just a guessing game.
Take a pic of where the sleeve is covered and post it up here. I haven't seen a covered up sleeve.

ok yeah im in class i will take some pics of it when i get home and post em up...i feel like a noob but i dont see how you would measure it and you cant from the top. also i was looking for the .253 over piston from arc and cant seem to find it. Im not sure if you could really bore it out that much but mdbike says you can so I will say he knows a lot more than me

I have one of MDBikes engines with the .253 piston. The block is a YAMAKOYO. These have the thick sleeve. Last I checked you could get a short block for $130.00.

Buddha

I have 3 Yamakoyo complete motors, and I am also gonna go with the piston set up you have with one of them. The problem I'm having is locating one(the .253 piston)......I can't find one, anywhere ?

i talked to tom at arc racing and picked up their 120 over piston. When you refer to the .253 piston he said that is referring to .253 over the 5hp briggs motor....not .253 over bore on the clone. He said the 120 over would require boring about 120 or so from the stock block.....is this what you are referring to when you talk about the .253 piston. Or did I not understand him correctly. After putting a set of calipers I do not see how you could bore .253 over stock on the clone. Let me know if i am understanding correct. By the way Tom at arc is the man and helped me out big time.

where do you get the yamakoyo motor? I have the harbor freight one and am not sure which one that is. but you are saying that the yamakoyo has a thicker sleeve than the harbor freight one?

can one of the mods delete this thread....everything in this thread has already been covered in others sry for not searching good enough

i know where you can get these (.253 over) and many more pistons at.

You have a PM.

what's with all the secrets, the info has been posted more than once by MDBIKE.

no secrets, people need to just search for what they want instead of asking.

jr race car has billet pistons. also blossom racing has the .253 over wiseco pistons

just about any jr dragster place has these size pistons.

hey just wondering, if that is you on the other forum that has made those offers recently then right on. Maybe 99% of the time people don't even bother to read the post except for you. So if that was you, way cool.

yes sir.

that was me

Yeah and those guys wear me out texting them info and where to find stuff daily. 3 of those guys are on this very thread

Buddha52 that little motor was very loud and crackled all through the streets. They use to call it the popcorn machine when I use to cruise it around.

Hey MDBike,
You are right about noise,the header that you sent lasted about 20 min. I got an RLV on it now and it still pops and crackles. This has got to be the loudest engine I have ever owned. It sure gets people attention. This thing loves rpms. Very happy with it.

I'm glad your satisfied with it.