[xstar99]

Hello everyone, I just got my grizzly 2 weeks ago its a 2003 with 4400km's on it. When i give it alot of gas it makes a knocking sound almost like its the coming from the motor. It seems to be coming from the motor area anyway but i dont know from where. Its been making that sound ever since i got it. It seems to run perfectly and i tried my friends grizzly 660 and mine seems to have the same amount of power. It makes that knocking noise in 2 or 4 wheel drive and only when i go fast or floor it. I changed all the oils in the diffs and motor and its still there..........ANY IDEAS would be appreciated.
Thank you.

 

[irv]

Not really sure on that one? It sounds like a bearing in the engine to me? Have you checked your compression and your valves? Is it the same knocking/pinging sound you get with under rated octane fuel? Bit of a long shot but you may want to try a higher octane fuel and see what happens(Sunoco Gold). What kind of oil are you using? Have you tried synthetic? What is the viscosity you are running? Try these things first and then take it from there. Good Luck........Irv

 

[dknarnd]

As Irv mentioned probably the first thing is to check the valves, maybe take a short piece of pipe and put it to your ear and the other end on the valve covers to see if the noise can be isolated to that area. Any leakage from either the front or rear diff or motor where the drive shaft enters? How about the axles, do they have play in them?

 

[xstar99]

I hope its not a bearing, I havent checked the compression but after trying another grizzly 660 and realizing that we have the same power im sure its not that. I thought about the valves but im not to sure that would be it either. Its definetly not the fuel i know what pinging sounds like and its not that its more of a light knocking. I also though that it could be the clutch maybe there is some loose pieces in there or no greese. I use synthetic oil from the yamaha dealer and used yamaha dealer oil for the diffs also. There are no leaks on the grizz's diffs at all i would see it on my garage floor for sure. The axles are perfect no play at all. What would the valves affect on the grizz if they were off set?
Thanks for your time guys i hope its something simple.

 

[jpmacmillan7473]

take the recoil start off see if it still does it ..mine had a **** of a racket in the motor a few weeks ago and i chased it to it ..hope it is as simple for you

 

[sneutel]

Grizz03, It may just be something silly and simple!
Remove the right plastic side cover, and check if the "heat cover plate" that covers the exhaust pipe is not loose! Often sounds more like a rattle than a knock!

 

[beavergrizz]

As Beast says the rubber washers under the heatsheild on the header melt and cause it to rattle. Mine did it.
If the Valve Lash gets out of specs you can get a rattle, usully more noticeable at idle, unless they get way out.
Pinging or predetination on a single cylinder engine will sound much more serious than a ping from the engine in your car. Much louder due to the fact that the engine is not insulated and positioned right between your legs.

Do you know the history of the machine before you bought it?

 

[xstar99]

Ill go check the heat cover plate now, The grizz at idle sounds perfect no noise at all.. I called the dealer to check the history on the grizz but they said it was never brought in for anything. I brought it to the dealer for the heat recall and ask them to look at it and they said it was ok. However they couldnt try it going over 50 which is when i hear it most....
Thanks guys. Hope i find it soon.

 

[xstar99]

UPDATE: the rubber washers under the heatsheild on the header seem to be still good there in tight. What i did find is that my rear brake rotor was loose all 6 alan key bolts were loose and i could move the brake rotor side to side like a steering wheel about 5mm to eack side. Do you think that might be it.... I hope so ill try it out tomorrow and let you all know.
Thanks

 

[irv]

Hopefully that is your problem Grizz03, that would be a nice easy inexpensive fix for sure! Good luck and let us know.......Irv

 

[xstar99]

ANOTHER UPDATE: ok so i just got in from a little ride, Its still makes that clacking noise so it wasnt my rear rotor that was loose. Im sure its not a motor bearing becaose the grizzly sounds perfect at idle and giving gas in neutral under 3/4 way. Its not the heatshield i held it with my gloves and there was no change.

So i looked into it a bit more and this is what i came up with in terms of letting you know what it does exactly...

When Driving 2 or 4 wheel drive It only starts to make noise over 45-50 km

If im in neutral and i just rev it up it only starts to make noise at 3/4 way throttle.

Im starting to think its something in the clutch because isnt there something that moves inwards with rpm? Is there something that would make it make noise?

Thanks again guys

 

[beavergrizz]

Yes the clutch does ramp up weather in nutural or in gear. Does sound like a clutch problem to me. I would take the cover off and look for something obvious.

 

[xstar99]

Actualy what i meant was the primary sheeve. Would the rollors or weight make a noise if maybe the greese is gone??

 

[drfrankenstine]

Mine did exactly the same thing. turned out to be the sprag clutch parts all worn.