Deglazing cylinder

Im currently rebuilding my 2002 yz426f that had 300 hours on the stock piston with a new stock piston and ring kit and reusing the cylinder. I need to deglaze the cylinder, and i will be using a ball hone and there are multiple options for the balls hones from the type of abrasive to the grit of the abrasive. Does anyone have any idea what abrasive and what grit to get?

I read on a GSXR forum that suzukis techs say a 240 grit Aluminum Oxide ball hone is best for deglazing a nikasil cylinder. Does that sound right?

Aluminum oxide is OK.  Don't use anything more aggressive than that.  Actually, I mostly use silicone carbide hones from Brush Research, and they produce excellent results.  Nikasil, of course is much harder, but remember that you just want to deglaze it, not change the size.

 

Order the 95mm (3 3/4") hone.  BR hones are sized by the bore size, and not by the actual diameter of the hone, so the 95mm hone is correctly larger than 95mm in order to put the proper pressure on the bore walls as you hone.

 

Lube the hone liberally with shop solvent (mineral spirits) or very light oil.  Use a 1/2" drill with a chuck RPM of 5-600 RPM, insert the wet hone, pull the trigger, and work the hone vigorously up and down the full length of the bore as it turns, so as to create the cross hatch pattern.  Hone the bore for 10 seconds, then pull the hone free as it is still turning.  If the hone leaves any shadows at the top or bottom where the rings stop, go 5 more seconds.  If it's still not cleaned, better get the cylinder measured precisely before proceeding. 

 

Wash with solvent or soapy water and dry it, then follow up with a clean, low lint cloth and some ATF (auto trans fluid), mopping out the bore with that.  You may be surprised how much black comes out on the cloth.  Results should look like this:

 

Before:

 

worn_zpsd05271f0.jpg

 

After:

 

honed_zps69da51cf.jpg

Aluminum oxide is OK.  Don't use anything more aggressive than that.  Actually, I mostly use silicone carbide hones from Brush Research, and they produce excellent results. 

 

Thank you for your help and very detailed reply grey it is apriciated. I just have one more question, what grit Silicon Carbide ball hone would you recomend? What grit do you use?   

 

And for the break in, is it fine to use my regular oil? I use Amsoil 10w-40 Full Synthetic motorcycle oil, or is there a better oil to use for the initial break, i want to achieve the best ring seal.

Edited by Yammer-Hammer
What grit do you use?   

 

240

 

 

And for the break in, is it fine to use my regular oil? I use Amsoil 10w-40 Full Synthetic motorcycle oil, or is there a better oil to use for the initial break, i want to achieve the best ring seal.

 

Assemble it and break it in with any oil, whether synthetic or not.  Use only a light film of oil on the bore walls an piston skirt. Once the piston's installed, lower it in the bore and wipe up any excess oil above the piston.  The rings will seal if the bore is correctly prepped and is round.  The quality of the seal is more dependent on how the engine is run during break in than on any other factor besides bore prep.  Warm the engine up well by riding it around under light loads for about ten minutes.  Shut it down, check the fluids, etc., then ride it at 75% of what it is capable of for 10-15 minutes or so.  Then work up to putting 3-4 good hard full throttle runs on it through one or two gears without running the revs way up to the limit over the next 10-15 minutes.  Then just ride the thing; break in's over.

So your positive SC is a better abrasive the AO? Ive read alot that AO is better. Which one of the two is harder?

Edited by Yammer-Hammer

AO is harder, but not necessary.  The work shown was done with SC.  The AO hone will last slightly longer, but costs more, too.  The SC hone would easily do 20-30 cylinders before being worn out, maybe more.  If I went with AO, I'd probably go to 320 with it.

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