400ex/416ex bigbore questions help needed

[ridein'red7]

so i got my cylinder and piston back from my dads friend who has been in machine shop for 30yrs and he bored and honed my cylinder but anyways i wana double check my piston to wall clearance because mine seems sloppy with it just sitting in there with no rings

[CJM]

With no rings in it, it will be sloppy. The rings are what act as a buffer between the cylinder wall and piston.

Put your rings on, compress them and put the piston in the head and see.

[ridein'red7]

yea bu isnt there a clearence you do with no rings on and do it from the skirts?? i am a 2stroke man not a 4stroker haha

[CJM]

Your supposed to check the rings for end gap of course.

I havent heard of checking the piston skirts. All I can say is I made sure my piston fit in good and my 416 has been running for some time with no issues.

paging ron or steve or johndoe!

[ridein'red7]

i can do the ring end gap but need the specs beacause i do not have the box

[CJM]

Then I would go to the piston makers website and see what you can find.

[ridein'red7]

ok il check wiseco but i remember on the box it had a 52 in it somewhere i wana say .0052??

[ridein'red7]

looked on the website and couldnt dig up anything anyone got an answer??

[honda400ex2003]

Originally posted by CJM
Your supposed to check the rings for end gap of course.

I havent heard of checking the piston skirts. All I can say is I made sure my piston fit in good and my 416 has been running for some time with no issues.

paging ron or steve or johndoe!

The piston sheet that was in the box may say what it needs to be. im not sure here. i went with what the guy gave me back. If he has been doing it for 30yrs i would say that it should be ok imo. I made sure my ring gaps were each 1/3 of a piston away from each other. thats how it came to me so i made sure it went in that way. steve

[CJM]

Im with steve, like I said I made sure the ring gaps were where they were supposed to be and checked the end ring gaps of course.

I believe if you were to email wiseco they could send you the info.

I was really nice and scanned the instructions for my wiseco 87mm piston. it should all be the same tho.

They are in adobe PDF in a zip file. ignore 2nd image in the first file. I messed up scanning it and the 2nd file is that page instead.

Let me know if you have issues with the file host

http://www.fileswap.com/share/399016a74069894e33ac7f9f075bd6b3/rings.zip.html

[ridein'red7]

thanks man u da bomb :D :D

[CJM]

No problem, glad to help ya out.

[ridein'red7]

so one more question i found the box and it says clear(for clearence i assume) now is this ring clearence or piston to wall clearence??

[JOHNDOE83]

If the guys been in the buisness for 30yrs, Id trust his knowledge especially if he's a friend of my dad's.

without the rings in place the piston will of course be sloppy in the cylinder.

As long as its a good firm fit when installed in the cylinder, all will be fine, the clearence and gaps are all factors for the machine shop, avereage people like me dont have tools for that stuff...lol.

Machine shops have formulas for that kind of stuff and simply knowing what mm size the piston is, they can do a bore in their sleep, most of those guys automatically know from years of boring and honeing what size to make all clearences for rings based on piston dimensions.

Anytime Ive done a bore and hone, Ive just given my info to the machine shop and they made everything fit just fine, if I were you. Id install everything, do a compression test, if all checks out, try to start it and start breaking in the motor.

If any issues arise, or if you just wanna make sure of something, try to contact the machinist that did the work and show him the cylinder with the piston and rings inside for some re-asurrance that everything is fine.

[ridein'red7]

yea its my first fourstroke build im a 2stroke wiz

[ridein'red7]

so i just took the digital dial caliper and the piston reeds 87mill and the jug is 87.3/87.4 :(

[CJM]

The rings will take up that little bit of the gap or your measuring could be slightly off.

[ridein'red7]

im just paranoid but should i just slap it together n run it like a Honda?