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Discussion Starter #1
03 Grizzly 660

So this summer my needle valve on my carburetor stuck at some point during a ride. I proceeded to get gas into my air box and into my oil. I didn't realize it right away and my wheeler sat for about 3 weeks. I then realized coming back to my bike that it had a stuck needle valve I went ahead and rebuilt and replaced Parts in the carburetor, drained and changed oil and filter. Everything was great for about a month but just went out on a ride and came home to clean up my 4-wheeler after a muddy Trail and noticed now that I have oil coming out from the head gasket. I obviously need to tear it down and rebuild however I'm wondering if anyone has opinions on the fact that my wheeler sat for a few weeks with an oil and gas mixture if that would have caused weakening in the gasket material?

Any opinions and suggestions welcomed thanks!
 

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highly doubt they are related at all. What's mileage on bike ?
 

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Fuel is a very "thin" liquid when compared to water for example, if your piston stopped near TDC & the leak was enough to keep a pool of fuel constantly in the chamber before slowly leaking to the bottom end it's possible that the fuel could degrade the gasket material(especially around the oil return gallery area where the gasket is thinnest) to the point where when you start the bike next(with liquid fuel in the chamber) the compression ratio goes sky high & damages that area further causing oil to sneak out of head gasket, it can also cause a thing called hydraulic lock which can bend the conrod(lets not go there!). When guys came to the shop I worked at with this problem they were told to do the same thing you have done & wait & see if it caused more damage, some get lucky, some don't :frown2:
makes a good case for turning the fuel valve off though.
 

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Wow, that a fair amount of mileage / hours!
 

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X2 on what guipago said it makes sense. With that many miles the head gasket could have been on the edge.
 

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Mine made it 3k miles lol.
 

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Discussion Starter #8
I got my 660 torn down today, I didn't notice any obvious damage to the gasket in the area that it was leaking. I am not sure what to think about that. Also after comparing the old vs new gasket I see minor differences. First off the material itself, secondly there is a hole missing right where the leak happened. Any reason for concern wit the new gasket? Should I get another that is exactly like the old?

Thanks for the replying it's much appreciated.
 

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I got my 660 torn down today, I didn't notice any obvious damage to the gasket in the area that it was leaking. I am not sure what to think about that. Also after comparing the old vs new gasket I see minor differences. First off the material itself, secondly there is a hole missing right where the leak happened. Any reason for concern wit the new gasket? Should I get another that is exactly like the old?

Thanks for the replying it's much appreciated.

I always thought the paper gaskets are for base gasket only. Head gasket should have metal in it of some sort like a fire ring impregnated or thin metal shim with some kind of material on both sides to seal fluids
 

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X2 to WW above

obvious, but just to confirm your concern, your pics are showing gaskets for 2 different locations, correct?

the metal gasket in the first image is the cylinder head gasket (between top of cylinder and head)

the green fibre gasket is the cylinder gasket (between block and base of cylinder.)

2 completely different parts.

and since the head gasket blew, for any reason, in this case maybe appears to be fuel hydrolock, .. and especially with aluminum heads and cylinders, you DO want to check the head and cylinder deck for any warpage..if its warped, it will probably blow again.
 

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Discussion Starter #11
Well, this has been a great learning experience for me. I wish I could say everything went great and I am riding again.

I have my bike all back together and it idles great but as soon as I give it throttle it bogs down hard. Back fires and refuses to take off.

I have a manual and follow it when disassembling and reassemble. However knowing that I took the top half off and replaced the top end gaskets do these problems jump out at anyone? What I may have done wrong?

Thanks in advance.

PK
 

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Well, this has been a great learning experience for me. I wish I could say everything went great and I am riding again.

I have my bike all back together and it idles great but as soon as I give it throttle it bogs down hard. Back fires and refuses to take off.

I have a manual and follow it when disassembling and reassemble. However knowing that I took the top half off and replaced the top end gaskets do these problems jump out at anyone? What I may have done wrong?

Thanks in advance.

PK
Recheck your timing. It could be off by a tooth.
 
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