Cylinder Prep

Got questions? We got answers....
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Cylinder Prep

Post by Jeb »

Since the KDX cylinder is made with the electrofusion process, is there any cylinder surface prep normally done when changing out the piston? My understanding is the coating in the cylinder is very thin. The on-line manual mentions only that no boring or honing is done on this cylinder.
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Lightly with a dry scotch-brite pad only.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

>|<>QBB<
Indawoods wrote:Lightly with a dry scotch-brite pad only.
So we're talking basically just buffing up the glaze, right?

This is a more generic question because I really don't know any better (and maybe it doesn't matter) - is any particular pattern or direction preferred?

Thanks Inda!
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Yes... just breaking the glaze. I just stick the pad in and turn the cylinder and my hand around a few time and it's good.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
KDXer
Supporting Member
Posts: 2845
Joined: 12:11 pm Nov 12 2004
Country:
Location: Sydney, Downunder

Post by KDXer »

GREEN ones NOT the RED ones. I used the pad much like you would a hone.
Image

"I want to die peacefully in my sleep like my grandfather, not screaming in terror like the passengers in his car."
AZRickD
Member
Posts: 524
Joined: 08:51 am Jun 29 2006
Country:

Post by AZRickD »

Cross-strokes, right ??

Rick
I done KX-ed QuailChaser's KDX220R
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Your not honing it... your just breaking the glaze.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
IdahoCharley
Supporting Member II
Supporting Member II
Posts: 1005
Joined: 06:57 pm Mar 19 2005
Country:

Post by IdahoCharley »

I don't think the color matters.

Brown will take more effort than the green scotch pads with the burgundy (red) ones taking the least effort. (The gray ones are somewhere between the green and burgundy ones.) I believe the bore is coated with tungsen/molybdenum and steel composite which is not going to be abraded away by hand use of scotch bright pads - IMO

Bottom line for me is - if a cylinder has sever glazing I will use the burgundy or gray color pads since it seems more efficient and the pads stay intact; since I'm not scrubbing the cylinder surface as hard trying to break the glaze.

Like Inda says - your breaking the glaze only - no way are you honing the cylinder!!

P.S. I do believe most people stick with the green scotch bright pads because everyone seems to have the pads in their tool chest or under the sink.
KTM 380EXC Mine
KDX 200 Mark's
TTR 125 L Wife's
KDX 200 Austin's
EC 300 Tyson's
WR430 Husky - mine
User avatar
stringburner
Supporting Member III
Supporting Member III
Posts: 221
Joined: 06:18 pm Oct 12 2006
Country:

Post by stringburner »

I was reading in the KDX owners manual the break-in procedure. Then it says to install a new set of piston rings for optimum results. Wtf? I thought that was the whole purpose of breaking in, to seat the rings...
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

>|<>QBB<
stringburner wrote:I was reading in the KDX owners manual the break-in procedure. Then it says to install a new set of piston rings for optimum results. Wtf? I thought that was the whole purpose of breaking in, to seat the rings...
Go to the link listed below. Click on "KDX Tech Tips" ** and choose "New Bike Prep" under the GENERAL***. It seems to give a reasonable explanation.

http://www.dirtrider.net/justkdx/

There's some other good links as well. The topics are brief and generalized but they seem to make sense and they'll get you thinking. Then when you want more details/specifics on a particular topic come as the seasoned experts on this site!!

** If you'll right click on the link and select "open in new window" you'll get a better view

*** If you can't see the text, click and drag over the page and you'll see the text: it's as if both the background and the letters are white. :roll:
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
stringburner
Supporting Member III
Supporting Member III
Posts: 221
Joined: 06:18 pm Oct 12 2006
Country:

Post by stringburner »

Thanks Jeb. I appreciate the link. It does make sense I guess. I just never thought of "breaking in" to mean the rings to the piston, but rather the rings to the cylinder. I don't know much I reckon. :neutral:
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

I think that statement is silly myself.... saying that the rings don't have to seat to the cylinder????
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
bradf
Gold Member
Gold Member
Posts: 703
Joined: 02:17 am Dec 11 2004
Country: USA
Location: Anderson, SC

Post by bradf »

Silly? Let's be blunt. It is stoopid and illogical. Parents, see what too much Saki does to kids!
'04 220 w/'01 KX250 USD forks, '02 RM125 Showa shock, Rekluse EXP 3.0, LHRB & all RB'd
johnkdx220
Supporting Member I
Supporting Member I
Posts: 74
Joined: 08:48 pm Nov 15 2004
Country:
Location: Québec

Post by johnkdx220 »

Eric Gorr also recommend using the scotch brit pad method.

My tip: Roll the scotch brite pad around a roller paint brush. Its the right diameter and enables you to do easy in-out-twist motions with risk of scratching anything.
KDX220 (RB'd, EFM Autoclutch, FMF Rev, KX front end... Crash proofed and crash tested tOO often !)
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

>|<>QBB<
johnkdx220 wrote:Eric Gorr also recommend using the scotch brit pad method.

My tip: Roll the scotch brite pad around a roller paint brush. Its the right diameter and enables you to do easy in-out-twist motions with risk of scratching anything.
Cool!! Very creative
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

The link about "break-in" was more to provide some insight about what the writer was saying in general, i.e. mfg flashing, look for scoring, etc.

I, too, was trying to understand ring-to-piston sealing vs. ring-to-cylinder sealing (I wasn't ready to call anybody "stoopid" though). And then I pulled the green "M Series Piston Installation Instructions" pamphlet that came with the Wiseco and re-read it. It states that for cast iron sleeved cylinders, ". . . to ensure poper ring seal, it is necessary to hone the cylinder . . . " and that " . . . crosshatch is necessary to ensure proper ring seal and adequate lubrication." The pamphlet goes on to say that for "plated cylinders" - which include Electrofusion - ". . . if the plated cylinder is in good condition" that deglazing may not be necessary. No mention of ring seal.

I thought ring-sealing was, in the presence of the crosshatched cylinder surface, the fresh piston rings literally resurfacing the cylinder surface for a smoother, tighter clearance. If that's right and you don't crosshatch a plated cylinder, exactly what kind of ring-sealing will be occuring in my 220? And, please, if I'm wrong - let me know how :grin:

Ring-to-piston sealing? 'Don't know about that yet, and I'm lookin', but I'm not ready to buy the ring-to-cylinder seal for the kdx quite yet.
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

They are dis-similar.... therefore they MUST seat to provide a good sealing surface.... period. If they were made of say... Jello.... then yeah... no breakin needed and they will seal perfectly.... :roll:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

>|<>QBB<
Indawoods wrote:They are dis-similar.... therefore they MUST seat to provide a good sealing surface.... period. If they were made of say... Jello.... then yeah... no breakin needed and they will seal perfectly.... :roll:
. . . and how are they seating? Of what exactly is the seat/seal comprised?

. . . and what is happening to the cylinder wall as a result of being forced to use a non-gellatinous substance for rings?
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

It is a high pressure fit... the ring forms to the cylinder and any imperfections are worn into the softer ring material forming a closer seal fit.

I imagine on a 0 hour motor with an absolutely perfectly round cylinder with a perfect coating and brand new rings... it wouldn't be as much of a concern but Ma Kaw has been known to make more than a few mistakes from the factory.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Re: 'It is a high pressure fit... '

When the intake charge lights off, it's certainly a high pressure fit!

THAT is what seats the rings. Pressure, yes..but pressure coming from the burn, not merely the rings spring-fit against the cylinder.

Re: 'I thought ring-sealing was.... the fresh piston rings literally resurfacing the cylinder surface for a smoother, tighter clearance.

'Resurfacing' doesn't happen. SEATING does happen.

Piston to cylinder clearance is important, too. A large part of that seal is a result of mixing oil with the fuel. Same for the ring-to-cylinder seal.

Remember the 2-stroke is pumping air on both sides of the piston.

Re: 'The lining is incredibly hard so the chances of actually tearing the lining is very very slim..'

MY 'chances' of 'tearing the lining' have been 100% when there have been ANY piston problems. I guess that makes me special!

Something to keep in mind: Not everyone agrees with the type of 'break-in' described on CDave's site.

Where to find another approach?

How 'bout HERE!??

:wink:

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply