a friend of mine had a 400 scrambler jug bored and i thought i remember some one telling me that the jug was supposed to be coated... i was wondering it this was true and if so what is it supposed to be coated with... im asking this because he just recently just blow the motor and i wondered if that had some thing to do with it...

 

https://atvconnection.com/D...h/Cylinder-Boring.cfm


There is no coating involved on a polaris ATV cylinder - unless you are refering to a coat of oil . Click on above to read about cylinder boring .

Rick

 

Nice set up Rick,I've had my old Boremaster going on 21 years now and it was used when we first got it! Lot of cylinders have gone through it! It may be old ,JUST like me,but still works fine! Good luck

 

Thank you - nice of you to say that .

What that machine is is a Kwikway . I bought is used in around 1986 . It is a 1973 or 1974 model . The hones of course are sunnens , they are about the same age .

Kwikway had some money issues here a while back - I hear I can still get parts for it - I just haven't needed any .

Rick Ritter

 

thanks that was very informative... but what i am talking about is after the boring process... this is the only motor i have takin apart on a atv... i head bored by my local atv shop with no problems... but after that i was told that your not supposed to bore them because it removes the coating on the bore... i think its a nickle coating or some thing like that... IDK for sure though... i your link there you mentioned that you were boring cast iron jugs... this is not a cast iron just, its cast aluminum with some type of steel sleeve... when my friend smoked this motor before he completely melted the piston in it but it did absolutly nothing to the bore... you could still see the honing marks with a problem... the only reason it got bored was because he figured sense it was apart why not... and now im about to go take it apart again because the motor seized up on it after about 150 miles or so... but some of that had to do with the a coolant issue or lack there of... but anyways... how much gape should there be between the cylinder and the piston on that? i was just curious for when i take it apart... well thanks for the info and i hope to here back

 

Aproximately about .0015 clearance between bottom of piston skirt to bottom of cylinder.Can semi accurately measure with piston in cylinder at bottom with feeler gage to get an idea of clearance. Hold piston and cylinder on one side and see if feeler gage has slight drag against cylinder wall on opposite side. When they reach about .004-.005 worn out,can usually hear em rattle, when larger is when they usually break piston skirts. NO coating as Rick said, just a BOREABLE sleeve. The new 850XP has a coated cylinder,not any of the earlier Polaris engines. Good luck

 

thank you again for the info