Just a few thoughts that have crossed my mind, in case you haven't already checked them out: (an '07 with 179 miles on it, the original engine without piston upgrade?)
check oil level, weight of oil(not sure if your in a cold climate), oil pump issue (is oil getting to the valve train?..lift a valve cover and look for good flow), pre-detonation/timing issue (check timing marks on flywheel and cam gear at same time. Any chance this motor has had a rebuild/higher compression piston?) is a valve adjustment needed, balancer out of sync after a rebuild.
I'm sure others will have more to consider.
Good luck!

 

Yes, all original and stock oil straight from the factory. This is virtually a brand new bike that just hasn't seen much time out of a garage the last couple of years. The previous owner has a disability which prevented him from riding and it had gotten to the point where he could no longer ride it.

Thanks for the input. I have most of this on my list to verify.

The oil is a good suggestion that I hadn't thought about. It is a tad low right now and an oil change is also on the list of things to do this weekend.

 

If i would have paid atention to all the noises my 07 grizzly makes i would've gone crazy by now.It made a knocking sound(most probably from the clutch area) since day one.
I would only get worried if i hear strange noises from a distance of at least 3 meters.
These are noisy engines.

 

my 08 has had the same knock since it was brand new, got 1100 miles on it now. i wouldn't worry about it too much these are not known for being quiet motors.

 

I also give a vote for clutch noise. Mine made the noise from day one, and the dealer told me that the knocking noise was normal. I have had no problems since then, and it has not gotten any worse. It is most pronounced when cold.

 

clutch noise. My Grizzly hammers like crazy. Loud when cold, then gets better. But, after you ride hard for a couple hrs, it gets louder. My Rhino is much more quiet, but doesn't have the miles/hrs on it the grizzly has. It's the only thing I don't like about a cvt.

 

I put 50+ miles on it between yesterday and today and what you described is exactly what this one is doing. When cold it is noticeable, then goes away but returns louder after hard riding. I didn't notice any lose of power or performance today so I'm going chalk this up to being normal even though my 09' does not do this.

I did a thorough inspection of everything over the last couple of days including checking valves, etc.. etc.. and everything looks great.

 

Mine knocks pretty good at startup, then not quite as hard. I also feel like its spreading the oil around and its just a tad quieter. I have a 550, so I'm glad to find out this is normal.

 

I just purchased a 08 grizzly 700. It makes the exact noise desribed in this forum. (knocking from the clutch cover) Until I read this , I thought I got ripped off. I thought the bottom end of the engine was gone.
Does anyone know what exactly is making the knocking noise????
Is it the wet clutch inside the engine? , The clutch weights?
I removed the plastic clutch cover then started the bike , it was very loud. I emediatly shut the bike off and removed the aluminum cover with four mounting brackets and the center alighnment hole. I then started the engine and the noise was gone. I believe the noise is generated in that aluminum stabalizer (it is the aluminum cover that has four mounting brackets on each corner and has a center hole in it that the main shaft goes into and covers the primary clutch) When I removed this and started the engine the noise was gone. I placed that cover back on and just held it in place with my hand , started the engine and that knocking noise returned.
I am puzzled. I would love to understand why these grizzly make that knocking sound.
Ross

 

I bought a 550 last friday, & I noticed it knocking right away! It almost sounds more like a low octane ping than anything. Stays the same hot or cold, but is louder loaded at a lower rpm. Also, I hear a squeak at idle once its warm. Sounds like a motor mount or even the exhaust shield right off the motor. One more, the right rear rotor also squeaks under 10mph. Ugh!! Not even 20 miles on the quad!!!

 

one thing that helps with the noise is to get a 2" exhaust tip. i had my friend make one where he works, and it gave my grizzly a nice deep sound. but it doesnt cover up all the clutch noise.

 

Did you figure out what caused the knock? Mine is doing the same thing and I would love to know what it is?

Thank you...

 

Agreed. I want to know as well.

My bike knocks a little when im idiling at start up but its not much. I have 8 x 14g Kodiak clutch weights.. i wonder if this makes a difference?

I just bought the bike and I believe they put a 5w oil in it. She is getting her oil changed this weekend to a 10w because of the heat down here. What oil brand do yall suggest?

 

I can't hear no knocking on my two grizz, course I got an HMF with no quiet core on one and a full muzzy with no quiet core on the other. :icon_ goofy: