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Top end Cylinder prep

By VeLcRo,
in Honda 2 Stroke

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Wiseone

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According to the weisco piston installation instructions I have to scrach up the cylinder walls with sandpaper. Is this true it cant be right? That would make for bad seal right?

Uhmm I have the Wiseco Piston installation instructions in my hand and it reads.

Cast Iron Cylinders: DO NOT install a new piston and ring without Honing the cylinder to break the glaze. Finish hone with 280 grit or finer. Crosshatch is necassary to ensure proper ring seal.

Plated Cylinders. IF the Plated cylinder is in good condition Honing may Not be Necasssary. If Deglazing is necassary DO NOT use a ball hone. Use a rigid or brush type Diamond Hone.

I do not see anywhere present or past that instructs to scratch up the cylinder walls with sand paper.

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CharlieT

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Personally, inspite of what Wiseco says, I would not use a diamond hone on a plated cylinder especially a rigid hone. A diamond hone is one thing can can actually dimensionally alter a coated cylinder. A diamond hone will cut the nikasil. Much less likely with a diamond brush hone, but I wouldn't risk it. I've always used a slica or aluminum oxide impreganted nylon brush hone, around a 240-280 grit. Unless you need to alter the dimension for clearence purposes, all you really need to do is remove the glazing. You don't need a diamond hone to do that.

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kelstr

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Personally, inspite of what Wiseco says, I would not use a diamond hone on a plated cylinder especially a rigid hone. A diamond hone is one thing can can actually dimensionally alter a coated cylinder. A diamond hone will cut the nikasil. Much less likely with a diamond brush hone, but I wouldn't risk it. I've always used a slica or aluminum oxide impreganted nylon brush hone, around a 240-280 grit. Unless you need to alter the dimension for clearence purposes, all you really need to do is remove the glazing. You don't need a diamond hone to do that.

you must hone any cylinder you ever do with a flex hone ( silicon carbon---diamond really is needed for nikalsil --but the silicon works )

and yo must spend alot of time cleaning the bore and piston and rings with brakcleaner and rags until its all clean and install the piston and rings all dry .

you must not put any oil on the cylinder or rings at all ever ,

then with the motor all assembled you slowly turn the motor over 60 or so times to seat the ring and or rings and there you go --just like any motor --2 stroke or 4 --diesel or gas --

the plated and or nikalsil is so hard it will wear out the hone long before you ever make any measurable difference in the plated cylinder at all----i know ---i have tried it !! ?

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VeLcRo

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I just finished putting the bike back together and it definitely has more snap! I just cleaned the walls with a papertowel and put the new piston and ring in and we'll have to see how she runs after break in!

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kelstr

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Is there anything wrong with just using a Scotch Brite pad to deglaze the Nikasil liner?

well , you can rap a scotchbrite pad around a three blade hone and make it kinda work on a 4 stroke but it can be hard on a 2 stroke because it wants to hang in the ports with as much pressure as you end up putting on it ,

if you do not have flexi dingle ball diamond silicone hone thining ,

you can get PLUMBERS TAPE ( kinda corse emery cloth stuff )

at home depo or a hardware store ,

and you can rap the tape around your fist and hold your cylinder under hot water and fist the cylinder ( boy this sounds queer or good --depending on how you mind is set up )

and the tape actually will brake the glaze to a nice dull crosshatching that you can assemble all clean and dry with and seat you rings on ,

its crude but i have done it for lots of people at the track when you had nothing else to use and had to get her done !

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CharlieT

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you must hone any cylinder you ever do with a flex hone ( silicon carbon---diamond really is needed for nikalsil --but the silicon works )

and yo must spend alot of time cleaning the bore and piston and rings with brakcleaner and rags until its all clean and install the piston and rings all dry .

you must not put any oil on the cylinder or rings at all ever ,

then with the motor all assembled you slowly turn the motor over 60 or so times to seat the ring and or rings and there you go --just like any motor --2 stroke or 4 --diesel or gas --

the plated and or nikalsil is so hard it will wear out the hone long before you ever make any measurable difference in the plated cylinder at all----i know ---i have tried it !! ?

Well, I'd have to agree and disagree. I think we are probably being a little too picky for your avg rider's engines. We have altered the bore of a Nikasil coated cylinder with diamond stones. Now, did we "bore it"? Well, no not exactly. What's the thickness of most nikasil plating... .002" -.004" depending on stock v aftermarket recoat? So no, your not going to "bore" a Nikasil cylinder at all comparative to a steel liner. However, we have successfully changed the dimension by .0004-.0006". Yeah not very much at all, but our supplier for some time could only get us the psiton we ran in a 53.95 size. On our cylinder we were running, that gave us around a .0014" clearance We had been running 53.93 pistons, which had given us right around .0019-.0020 clearence on this particular cylinder. Using diamond stones, and from what I recall, a fair amount of pressure on the stones, we were able to get the cylinder out to where with the 53.95 pistons we were running .0018-.0019" clearence. Maybe not any significant difference, especially if you got some one running pistons where you already got .0025-.0030 clearence and granted most people probably wouldn't consider altering a bore by .0005" to be any thing of signicance and probably wouldn't even consider it truly "boring a cylinder".

As far as the diamond flex hone, like I said, you probably are nnot going to alter anything because there simply won't be the presure applied necessary

to change anything. But they are not really necesary. In fact the one shop we had do the diamond "boring" on our cylinder felt that the diamond stones left too rough of a surface....peaks and valleys.... and he always did a final pass thru with an alum-oxide stone to give it a plateau finish and increase the ring contact surface.

BTW......this is right off Eric's site:

"These hones are available in several different materials and grits but the profile that bests suits both steel and plated cylinders is aluminum oxide 240 grit"

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kelstr

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Well, I'd have to agree and disagree. I think we are probably being a little too picky for your avg rider's engines. We have altered the bore of a Nikasil coated cylinder with diamond stones. Now, did we "bore it"? Well, no not exactly. What's the thickness of most nikasil plating... .002" -.004" depending on stock v aftermarket recoat? So no, your not going to "bore" a Nikasil cylinder at all comparative to a steel liner. However, we have successfully changed the dimension by .0004-.0006". Yeah not very much at all, but our supplier for some time could only get us the psiton we ran in a 53.95 size. On our cylinder we were running, that gave us around a .0014" clearance We had been running 53.93 pistons, which had given us right around .0019-.0020 clearence on this particular cylinder. Using diamond stones, and from what I recall, a fair amount of pressure on the stones, we were able to get the cylinder out to where with the 53.95 pistons we were running .0018-.0019" clearence. Maybe not any significant difference, especially if you got some one running pistons where you already got .0025-.0030 clearence and granted most people probably wouldn't consider altering a bore by .0005" to be any thing of signicance and probably wouldn't even consider it truly "boring a cylinder".

As far as the diamond flex hone, like I said, you probably are nnot going to alter anything because there simply won't be the presure applied necessary

to change anything. But they are not really necesary. In fact the one shop we had do the diamond "boring" on our cylinder felt that the diamond stones left too rough of a surface....peaks and valleys.... and he always did a final pass thru with an alum-oxide stone to give it a plateau finish and increase the ring contact surface.

BTW......this is right off Eric's site:

"These hones are available in several different materials and grits but the profile that bests suits both steel and plated cylinders is aluminum oxide 240 grit"

yes the 180 and 240 grit flexi hone is what i use on just about everything,

i have some diamond flexi hones also witch work very well on a plated cylinder, and when you are just honing by hand with a dingle ball flexi hone you can not alter the size of a plated cylinder ----

your really just cleaning and braking the glaze to leave a nice rough plateau crosshatch to get the rings to become sized and beaded into the cylinder bore,

this is something that i see alot of people do wrong is the cylinder prep ,

and it is so important to hone and do a dry assembly prep to get the rings to bead and become one with the cylinder ,

its one of the things that separates a super running motor that lives from just a running motor that is short lived.

clearance , prep ,dry assembly and cleanliness are so important

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SC_Spode

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hey SC ---lets go ride and have fun,

i have been mountain biking to try and stay in shape---

i broke my ribs alittle while ago and i am finally kinda strong again from that . ?:applause:

Man, I'd love to twist the throttle a bit, this year hasn't held much in the way of riding time. :applause:

Sorry to hear about the ribs, that can make breathing a bit rough. But what the heck, it's probably overrated. :ride:

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kelstr

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Man, I'd love to twist the throttle a bit, this year hasn't held much in the way of riding time. :ride:

Sorry to hear about the ribs, that can make breathing a bit rough. But what the heck, it's probably overrated. ?

:applause::applause: so true !

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  • 4 months later...
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jamesecox

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kelstr, ive heard of doing a dry top end rebuild on thumpers, but this applies to 2-strokes too? i've always thought you were supposed to use a little bit of oil on the rings and smear the cylinder with oil when assembling it.

I always coat 2-Stroke cylynder walls with pre mix prior to assembly never had a sealing probem, took a stock RM250 to Lorettas in Aug. I would not dry cycle any metal to metal surface ever! Here's my routine (2 or 4)

1. Scoth Brite Cyl

2. Clean

3. Clean More

4. Oil and assemble

5. 2 - 5 minute warm up cool cycles

6. 10 min varied trottle less the 50%

7. Inspect, change oil, change plug

8. Beat without mercy.

Never had any problems leak down tests always good.

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