From day one I thought my new 2008 Sportsman 300 had a rather loud engine. I found one reviewer online who said the same and the dealer said it was typical of the 300. However, along with the loudness I soon heard what sounded like a rocker-arm kind of noise whenever I throttled up--as if something was pinging the top of the cylinder (a sharp kind of knocking during acceleration). Two years running I've had no problems with the 300 on the trails. However, now the engine seems to be getting ever louder and that accompanying knocking sound at acceleration is getting louder too. Anybody out there want to comment on what the 300 is supposed to sound like? I'm thinking I'll take it into the repair shop soon, but I would love some imput before I spend the $. Thanks

 

Not sure how much my 02 325 differs from your 300 but it's always had that pinging/knocking sound. When it was newer you could hear it but as it's gotten older the knocking has gotten louder. The knock fades away as the rpms come up. I talked to my dealer about it and they claimed that was normal with some of the smaller engines. I've learned to except it. 8 years old and still runs like a top.If the knocking gets louder as the rpm's come up then I might be a little more concerned.

 

I have found that all the Haweye 300's that I purchase for export are loud.

www.thorexport.com

 

my 07 trailboss is louder too.

 

Its an aircooled engine has lots more clearances built into the rotating parts. Also valves need adjusting @ 100 hrs. The noises are normal ! Good quad.