How can you tell if a cylinder needs to be replated with Nikasil?

[Hoosier_Daddy]

The cylinder I took off my Tecate looks really good. It ran good when it was together but I have no clue how long it went without a rebuild or anything. There is no scars or scratches or gouges in the cylinder and when I use the calipers the measurements are pretty good around 70mm. I don't know the tolerances for the measurements on the cylinder though. But, since the cylinder looks good, how can i tell if the coating is wore off? Is the Nikasil a different color or something?

[The Goat]

I always thought the nikasil flaked or cracked off when it went.

take the sucker to be honed for 5 bucks, if the guy doing it is halfway honest, he'll tell you if you need a new plating.

[racerxxx]

Hoosier,

got this from this site: http://kustom-kraft.com/NEWNIKASIL.html

How do you know when your cylinder needs be re-Nikasiled? Some times its not that easy to tell, but
usually you can tell by looking at the cylinder walls. If you can see scratches or chips that's a sure indication
that it's time to have your cylinder re-plated. If you can't see any wear or damage that doesn't necessarily
mean your cylinder is in good condition. The inside of the cylinder has to exactly round (to with-in specs) to
perform properly. This can only be accurately checked with a dial bore gauge. They can measure to with-in
one ten thousandths of an inch. The Nikasil plating that's on the walls of your cylinder is only a few
thousandths of an inch thick but is very hard. It wears extremely well as long as everything is tight and
sanitary. If you maintain your engine as the factory recommends it will last for years. However we all know
how easy it is to suck it full of water or dirt or maybe run it low on oil or some other mistake you'll be needing
our service. The Nikasil plating, or coating as its sometimes refereed to, will have to be stripped and re-plated.

When I looked into it I talked extensively to these guys : http://www.powersealusa.com/

I am local to them and they answered every question I asked without hesitation, they even took the time to explain the whole process to me. On my application I was looking to clean the bore up and replate to a standard bore. My cylinder had very light scratches--very light. They actually bore the cylinder just a few thousandths and then can replate(nikasil) back to the standard bore size and then final hone. If your looking to keep a std. bore it may be the way to go. You probably should have taken a compression test before the tear down, and you need to check the bore in several locations to determing the out of roundness of the cylinder bore if it is.

Call these guys or someone local to you and pick their brains.

Good luck!

[Hoosier_Daddy]

Thanks for all that info!

[tecat-z]

Yes, Racerx knows and is 100% correct. Typically they show first signs of wear at TDC when piston changes direction. A severly worn piston, and rings with low tension allow rings to flutter against liner at that location due to the extreme change in pressures taking place. I've seen a few old cores that have worn through plating and begun to show aluminum in extreme cases and even some where flaking has occured in that area. Nicasil has an incredible life span under normal conditions.

[The Goat]

can you have any cylinder plated? Like a fourstroke cylinder?

[cr480r]

When the plating wears through the lighter colored aluminum will show.. It usually wear off around the edges of the ports first.. If she is runnin decent put her back together and put your money into a ported or KX cylinder.. Any porting should be done before the cylinder is replated.

[racerxxx]

can you have any cylinder plated? Like a fourstroke cylinder?

I'm pretty sure you can do 4 stokers as well, I was told BMW's have it and I'm sure others as well. I believe Mahle(cylinders) invented it or something. It's been done for a long time now, it's just not something you hear of too often. Most shops wants to do a bore job and a piston kit. Dollar for dollar I think it's close to the same mabey a bit more for the nika but if its not scored bad they can get you back to a STD. bore. It actually sounds like a very cool process.