I have an engine rattle on acceleration in neutral and also whilst riding, that sounds like a big end is about to poke thru? Has anyone else had experience with this?

Second question, how do I check and adjust the ignition timing?
Many thanks from Ozz.

John

 

My 09 sportsman 400 HO has done it since new three months ago and the dealer said it is the oil pump and that the rattle is normal and that all polaris`s do it. Makes me awful mad that I paid $4800 for an engine knock!!!!!!!! Makes you embarrassed to even ride with other atv`s.

 

my 2008 started making that noise after about 150 miles,the noise is coming from the cvt cover,your dealer don't know what he's talking about,polaris oil pumps has always made that noise,that's in the motor,the noise you are hearing is the bearing and the starter clutch.

 

Thanks for your replies. My son in law has the identical machine, and there is no similar engine knock. It's totally different. It's a solid knock like a big end about to come apart.

I have heard of some engines giving a false indication if the ignition timing is way too far advanced. Hence my second question - how to I check and adjust the ignition timing? Can anyone assist please?
Many thanks,
John

 

I have a 2009 Sportsman 400 HO. Has anyone ever figured out what the engine knock is? I took off the belt cover and the recoil cover and ran it and the knock was still there. The only thing left is the engine clutch and inside the engine. It`s hard to believe that after four years nobody has found out what the knock is.

 

The rattle is the Bendix drive located under the pull start cover it fits loose, on start up other ATV rider just cringe when I start the ATV it rattle so bad, yes its embarrassing. LOL

The thumping or tapping is the oil pump but that should only during idle and go away once throttle is applied.

 

I started this thread. Since then my Hawkeye has had the engine rattle fixed by the dealer, following a phone call I made to the Polaris distributor in Australia. They were very helpful.
The problem was the centrifigal clutch buried inside the engine. Exactly which part came adrift, I'm not sure. But Polaris advised the dealer correctly about where to look for the problem. I gather the problem was not unknown to Polaris.
The machine feels like a different bike.
I think there is some recognition of a problem inside the clutch, but it is deemed not a necessary fix by some dealers. That was my experience with the first dealer we took it to.

So if you have a heavy engine knock or rattle on acceleration or when simply revving the engine when stationary, it could be the clutch falling apart. INsist on getting it fixed.
John

 

Well that sucks, welcome to the Polaris family. LOL