450r questions

[450R NOOB]

I bought an '05 450r with hardened crank, hot cam, jardine exhaust, and a jet kit a few weeks back and there are a few things I want to know.

First of all; some humming/buzzing has started at my front left wheel and I can't tell what it is. Maybe a bearing? Also, when I ride I hear a whistling noise mainly when I give it gas. Is this normal on 450s? And lastly, I know 93 octane is best to run in them (especially with the mods) but will running 87 hurt the engine?

Thanks

Also, how much will having the sprocket one lower than stock change the top speed.

[the Z Man]

Could be a bearing in the front, as for the whistling, are you running a lid on the airbox? if not there may be a leak in the carb boot.
Lastly, do not run 87 pump gas, at the least you should run 91 octane....

[S.A.J]

mine had some whistling when i was runing and i was told it was normal for them by a guy in town that has an atv performance shop.and gas wise what Zman said also sproket wise 14 is stock in front and going to a 13 will give you better low end power but will take away top speed and baisicly make the gears shorter but it'll give it more acceleration,going to a 15 of course has the oposite effect.

[k265r]

if someone updated to an fcr carb they whisle. dont know exactly the mph you would lose woulnt say more than 2 to 3 mph. always run good premium gas in these high performance 4 strokes.

[S.A.J]

not to start an argument but i think its more like 5-8mph that he would lose...

[450R NOOB]

I could only get 32 mph in 4th with the 13 sprocket (using 87 octane) according the gps. Does that sound right?

Thanks for the fast responses

[TJ Bradley]

Keep Running that 87 octane and The top speed will go to... Well however big a hill you have to roll it down in nuetral, or i bet you could hit at least 70 with it... in the back of the truck on the way to the shop. :D