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Discussion Starter #1
Ok folks, I bought a used 2008 Grizzly 350. The man selling it said he was riding it three weeks ago when it died. Since then it won’t start, but it does turn over. Here is what we’ve done:
1. Checked for “good gas”
2. Verified gas is moving to carburetor
3. Bought new carburetor and replaced
4. Changed spark plug, there is a spark
5. Changed battery
6. Sprayed starter fluid directly in
7. Removed spark arrestor and cleaned out muffler
It sounds like it wants to start, but just won’t come on. Any ideas?
 

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Discussion Starter #3
My guess is valve clearance

Ok, so I’m not much of a mechanic so how would I check the valve clearance?
 

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YouTube is your friend...thats how I did mine its a easy job for the most part just a pain to get to....get you a valve clearance tool and pull the exhaust and intake valve covers and adjust them to spec

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Welcome from Colorado.
Install a new plug first, there are many members that have learned you can see spark that is not hot enough to start the engine.
 
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X2 adjust the valves.
 
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Discussion Starter #8
Ok folks, I bought a used 2008 Grizzly 350. The man selling it said he was riding it three weeks ago when it died. Since then it won’t start, but it does turn over. Here is what we’ve done:
1. Checked for “good gas”
2. Verified gas is moving to carburetor
3. Bought new carburetor and replaced
4. Changed spark plug, there is a spark
5. Changed battery
6. Sprayed starter fluid directly in
7. Removed spark arrestor and cleaned out muffler
It sounds like it wants to start, but just won’t come on. Any ideas?
Welcome from Colorado.
Install a new plug first, there are many members that have learned you can see spark that is not hot enough to start the engine.
That was one of the first things I tried! We opened up the intake valve and it is very loose. It seems the arm holding the valve needs to be tightened. Sure hope that fixes it!
 

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Because the fault happened out of nowhere, I am doubtful valve clearances is the issue. Valve clearances tighten up over time and running issues will slowly get worse over time.

I would suspect more of a mechanical or component failure to your issue. Going solely on what you have written, I suspecting a sheared flywheel woodruff key. This is my best guess without being there to troubleshoot it myself. But I have been wrong before.
 
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Because the fault happened out of nowhere, I am doubtful valve clearances is the issue. Valve clearances tighten up over time and running issues will slowly get worse over time.

I would suspect more of a mechanical or component failure to your issue. Going solely on what you have written, I suspecting a sheared flywheel woodruff key. This is my best guess without being there to troubleshoot it myself. But I have been wrong before.
When you adjust the valve(s) correctly you need the engine in proper timing and for this I use the straw down the plug hole trick.
I get the piston to t.d.c. then look at the timing marks for proper alignment. With the piston up and the cam in the exact right position you should feel a little looseness in the rocker arm, the lash. To set the lash I use an angled feeler gauge. This setting is very important so be precise.
If the mechanical timing is off the lash will show up at the wrong time of the stroke, and if so the mechanical problem needs to be identified.
Then once exact mechanical timing is confirmed look to the key mentioned by dezz for proper firing timing. These do not have a distributor, but a crank position sensor for firing timing.
 
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Discussion Starter #11
Because the fault happened out of nowhere, I am doubtful valve clearances is the issue. Valve clearances tighten up over time and running issues will slowly get worse over time.

I would suspect more of a mechanical or component failure to your issue. Going solely on what you have written, I suspecting a sheared flywheel woodruff key. This is my best guess without being there to troubleshoot it myself. But I have been wrong before.
Thank you, I will check that out. We do know the valve clearance was WAY off. Got that fixed and will try again this afternoon.
 

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Because the fault happened out of nowhere, I am doubtful valve clearances is the issue. Valve clearances tighten up over time and running issues will slowly get worse over time.

I would suspect more of a mechanical or component failure to your issue. Going solely on what you have written, I suspecting a sheared flywheel woodruff key. This is my best guess without being there to troubleshoot it myself. But I have been wrong before.
My 660 was running fine then slowly died like it was running out of gas and would not restart but would just turn over I re adjusted valves and she fired right back up


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Discussion Starter #14
We pulled the woodruff key and it has damage. Had to order a new one, it will be here in a few days, we hopefully that fixes it. That could explain the intake valve clearance being way off, so we will reset once new key is installed.
 

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Discussion Starter #15
Update 9/3/20

The Woodruff key was messed up, so ordered and replaced. We reset the intake and exhaust valves. Still doesn’t start. Any new ideas?
 

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Sounds like you have spark and fuel and valves are correct could it possibly be the carb? I know you said you replaced it but maybe air fuel mixture screw adjustment??? I believe you said you checked the timing what about compression did you check it???

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Discussion Starter #17
Where is the adjustment on it? We’ve looked and looked. Haven’t found a good video. We haven’t measured the compression but it can be felt coming out exhaust pipe. Thank you for any and all ideas. May be taking to a mechanic if we can’t fix it soon!
 

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Where is the adjustment on it? We’ve looked and looked. Haven’t found a good video. We haven’t measured the compression but it can be felt coming out exhaust pipe. Thank you for any and all ideas. May be taking to a mechanic if we can’t fix it soon!
Is anything different choking it or giving it gas when its turning over

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Did you follow my detailed instructions above, and feel the lash after adjustment? And use the feeler gauge recommended?
I've had local buddys say they did the work, but the bike still ran like crap. Then later I checked and everything was wrong.
I'm not trying to hammer you, just asking because if you didn't feel the lash when done something was still wrong.
 
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