New too this forum, but wondering if anyone out there has any info too help me out would be great..

Ive been known too be alittle paranoid when it comes too engine noises, so i let it slide when i thought my bike sounded like it had a overly loud top end knock, mates told me all 450's sound like that.

But when i took it too the bike shop other day the mechanic pointed it out and he said that it is louder than normal but hes also seen other yz's twice as loud and stil going.
But its starting too do my head in!
Only bought the bike 5-6 weeks ago and it was like brand new 5-10hrs max. Problem is i dont remember hearing the noise when i got it.
Bear in mind the thing has copt a bit of a thrashing but no more than the average rider. i have done no more than 15hrs so all up no more than 25 hrs total

Any you guys out there in my boat that could shed some light on this topic would be greatly appreciated..

My '07 knocks a little as well. Always has since about my second or third ride. It's not bad, but I think it's caused by a little excessive wrist pin movement.

I'll find out later this year. I've got a planned engine tear down this winter.

My 07 Yz450f started hammering at or about the third ride also, at least that is when I noticed it. the bike is now on its second owner still not been rebuilt . the guy that rides it gets the hole shot more frequently than not.
the knocking noise to me seemed real bad . over time I got used to it and assumed it was part of the normal noise you get from a YZ.

dont you guys know anything?
when she knocks.. open the door:poke


no seriously yamahas are known for a little knocking.
but if it is too loud take it to your shop

They all sound like that.......rode the wheels of mine and it sounded like that from damn near day 1. Its inevitable on any one lunger that big with that much compression, they vibrate like hell, the pistons are very short and prone to piston slap...also, due to the vibration / power cycle of a single cylinder 4-stroke all of the other typical motor noises are amplified. Primary gear back lash, clutch rattle, transmission rattle, cam chain noise.
They are actually very durable motors, just always give it time to warm up before ripping on it (due to the short piston).

mine does the same thing its normal i think as long as its not too loud

yeah the ones that i have ridden all sounded like they were knocking,... hell even the R1's all tick :lol

gotta be a trademark or something with YAMAHA... :shrug

soooo im guessing its not a good idea to buy an 07 yz450f?? not that i really have the money but just for future refrence.... :notworking

soooo im guessing its not a good idea to buy an 07 yz450f?? not that i really have the money but just for future refrence.... :notworking

It's a normal noise for the YZ and most of the big single thumpers from other brands.
I had a 04 YFZ 450 that sounded like it had a knock, an 04 YZ450F that sounded the same, my friends 05 YZ450F sounds the same, my 06 KTM 525EXC sounds the same and the 08 YZ450F I just picked up sounds the same:thumbup

It's a normal noise for the YZ and most of the big single thumpers from other brands.
I had a 04 YFZ 450 that sounded like it had a knock, an 04 YZ450F that sounded the same, my friends 05 YZ450F sounds the same, my 06 KTM 525EXC sounds the same and the 08 YZ450F I just picked up sounds the same:thumbup
oo alright. i dont have much expericence with the thumpers. well at least now i no its not a big deal.
thanx :thanks

yeah the ones that i have ridden all sounded like they were knocking,... hell even the R1's all tick :lol

gotta be a trademark or something with YAMAHA... :shrug

The R1's is a different issue, the genesis tick is a whole ballgame/mess of it's own.

Nothing spells consumer confidence like motors that sound like they've got loose fastners and are about to fly apart.


just always give it time to warm up before ripping on it (due to the short piston).

:+1

the shortness of the piston skirts in these modern motors means you seriously can't f*ck around with the warmup time, they slap like a diesel when they're cold, prolongued cold start abuse leads to folded skirts, which is one of the main causes for failure on the 1 lungers. That plus stretched valves from overrev either on a missed shift or touching down and the wheel tugging the motor into a rev-range that's beyond reasonable. They're not like a 2-stroke you can't pull them past the rev limited on landing without consequences.

the knocking on the 450 is the piston hitting the front off the bore, it only happens at low revs , idle , i bought a 2007 YZ450f and it knocked bad , i stripped it down and it had put a fellable mark on the bore where it had been knocking , so i bought a new high comp piston and sent it off with the bore to get it measured so the bore can be re nickle plated and matched to fit the new piston exacltly , and guess What no more knock what so ever , thats why i know 100% the knock is the piston hitting the wall of cylinder , Yamaha said that for the 2009 450 the tightened up the tolerances to reduce engine noise

i have the same noise

I'm assuming the fuel being used doesn't have the proper octane rating needed for our bikes....