Just food for thought,I was wondering if Polaris made any changes in the new camshafts they offer today say for my 99 model which are known for wiping out the exhaust lobes.I know the part numbers are still the same

 

Does your sport. have a metal oil tank? In cold climates they build frost on the inside. The experts claim is the main reason for the bad cams.

 

i dont know if they changed anything on the new cams but i havent heard of anybody having any problems with the new ones.

the problem with the cams in those motors is they build the lobes out of too soft of metal. so i it causes premature wear

 

It was mostly the pre HO models that had the cam problem. The older models had problems running real rich after the jet needles worn down contaminating the oil and breaking it down. The cam was the weak link. I haven't heard of anyone with a bad cam in a newer 500 HO. The cams are interchangeable between the old and new models.

 

Lots of issues that could cause these cams to fail along with some others not mentioned I found on a web search like the cam oiling holes,use of nonsynthetic oils,lack of oil changes and the decompression ball cutting grooves in the rocker and eventually eating the lobe,I was chatting with a Polaris dealer last month and he stated people were over tightning the valves which caused premature exhaust lobe wear which I find hard to believe but it can happen,in a way he blamed it as owner neglect.Did Polaris ever have a solid answer to the cause,my thought was always non heat treated cam grinds and the exhaust lobe was more susceptible to wear due to the decomp ball