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Followup To
Question -
I have a 1995 articat zr580 efi that had burnt a hole in one of the pistons any idea what could have caused this.
thanks so much
Matt
Answer -
Hello Matt,
Having a hole in the piston indicates top-end upper cylinder over heating. The most common cause of this is spark plugs that are too hot. The correct plugs to the sled are NGK BR9ES, or BR9EYA if it is EFI. If you were using NGK BR8ES that would not pose a problem, unless the sled had a lean fuel condition or over heating problem. I would highly recommend checking the entire engine for wear, including the other piston, as you don't want to get a new piston installed, only to have the engine seize due to other areas being worn. be sure to look at the cylinder walls, there shouldn't be scoring on them. Also, make sure your sled isn't low on coolant, and that the oil pump is operating properly. These are some basic, common things to look at. If you have any other questions at all, let me know. Good luck with the sled! --Arcticatman
arcticatman
Thanks again!
Unfortunately in the course of time today i had installed another old piston and i thought i had checked everything to make sure everything was working properly but now it burnt a hole in the top edge of this piston.
Iam using br9es spark plugs all i can figure is that i have a bad cylinder.
thanks
Matt
AnswerHello Matt,
The cylinder itself being worn is a good possibility. Some things you also may want to look into is, water present in the gas and clogged jets. Both of these will cause a hole in the piston. Pre-ignition also causes this problem. Also, a quick way to check the seals is to start the engine and spray carburetor cleaner all over behind the clutch where the seals are (PTO) end. If the RPM's change, the seals are bad. If you decide to install a new piston, you may want to use premium fuel and a bottle of dry gas for some time. Let me know if you have any other questions. Good luck with the sled! --Arcticatman
