[Allgejeff]

Hello, I’m new here and have searched this forum and a few others and still looking for an answer. Please allow some grace if this is a stupid question, this is my first Polaris and post here.

Can anyone tell me if my 2011 550 sportsman has a nikasil coating on the cylinder?

Mine has been burning oil and needs rings and or a bore. I’ve got it apart and am trying to determine how to proceed.

 

[FPD218]

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Your question has now been logged into the queue and the next available forum member bp405 will answer you shortly

 

[bp405]

This is from the member room painter:

I think that most people confuse honing with de-glazing when it comes to Nikasil coated cylinders, especially regarding polaris engines.

IMHO Nikasil cylinders should never be honed unless being fitted for custom pistons that are just a tiny bit bigger (not a good idea for nikasil cated cylinders, again, MHO). On a polaris, the nikasil plating is NOT very thick, only about 0.003" so there is very little material that can be removed without compromising the cylinder wall.

A nikasil coated cylinder is light-weight with extremely long wearing surface that the piston and rings work against. Baring a mechanical problem that injures the coating, the cylinders will last nearly forever, and only rings, and sometimes pistons, which both wear FAR faster than the cylinder coating, can be replaced at fairly high mileages. The cross-hatch pattern of the cylinder is precisely controlled, and may well look almost original after many tens of thousands of miles, and a precisely done cross-hatch is one key to good ring break-in (controls rotation too!) and good oil control.

I have personally rebuilt probably 200 polaris engines in my home garage and have come to this conclusion:

99% of the time, Nikasil cylinders simply need to be cleaned up using a (red) Scotchbrite pad, followed by VERY thorough cleaning with hot soapy water and brushes.

If the cylinders are scratched or damaged enough to need honing, they really should be replaced or bored OR re-plated but this is not very cost effective thing to do. Most polaris cyclinders can be reclaimed if damaged, but they generally do not wear much under normal use enough to have to actually "HONE", and should not be honed in the classical honing sense when all you need is a new piston and rings.

I'm 99% positive our 550 is Nikasil. But This sounds like one for the forum "Godfather", Latebird!!!!!

 

[polman500]

Yep, its a plated cylinder. Just try to stick a magnet to it. That will tell you instantly.

 

[Allgejeff]

It might be worth mentioning the condition of the motor. It ingested some fine dust through the air filter. Prior to purchasing the vehicle a dealer installed a foam air filter without oil. I overlooked the un oiled filter on my inspection. After several long rides and one 100 mile ride in the dust it started burning oil and smoking.

I have torn the top end apart. There is no major scoring. There is a very light step you can feel in two quadrants where the piston reaches top dead center on the bore. Again very light.

I assume some glaze breaking is needed with a brake hone to make the new piston and rings bite. Given all the other warnings in the Polaris manual I was surprised they didn’t warn about boring a nikasil cylinder.

 

[Allgejeff]

By the way, it runs great, just consumes about a quart in 3 hours of riding. I tried Rislone a treatment to help the rings re seat and it fixed the smoking but still brurns oil. A cylinder leak test indicates leakage into the crank case. And is just barely in service limits. Compression test looked good, also, but the manual says the leak test is recommend.

commentary on preping this cylinder for the new rings is welcomed!!

 

[polman500]

Send it to US Chrome to be replated along with a new piston of your choice or just buy a kit that includes a cylinder and fitted piston if you want it to be right when you get done.

 

[Allgejeff]

For what it’s worth I found that a magnet sticks to my cylinder. Looks like it has a sleeve.

I also read on weisco’s website that magnets don’t stick to nikasil. This is contrary to what I’ve seen on here.

“Other forms of cylinders that aren’t plated commonly have iron or steel alloy sleeves. If your cylinder does have a sleeve, you should be able to see the seam between the sleeve and the actual cylinder. If you’re still not sure, check to see if a magnet sticks to the cylinder wall. If it sticks, it’s a sleeve, and if it doesn’t, it’s plated.”

Guide to Cylinder Prep for Your Bike or ATV Rebuild

Following the proper steps to prepare your dirt bike or ATV cylinder is necessary to ensure proper operation of the top end. Chamfering, replating, honing.

blog.wiseco.com

 

[Allgejeff]