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2005 Grizzly 660 need help

bloodymary

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Apr 7, 2025
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I don't know what happened but my 2005 Grizzly 660 suddenly stopped working. It can't start no matter how much I try, and I even wait out the morning spring weather and then try when it's hot at lunch time, but it still doesn't start. I think the problem is that the compression is just roughly around 100 psi? I already got the parts for the compression and I know I can fix that quickly but there's like something wrong with the carb or it's just that the air blows out of it before the engine dies. I don't get it. What's something I should focus on apart from the compression? I'm going to do the top end rebuild and update you guys on if anything changes.
 
Sounds like the valve timing is off. Check around the valves, could be that the woodruff key is starting to shear.
 
I don't know what happened but my 2005 Grizzly 660 suddenly stopped working. It can't start no matter how much I try, and I even wait out the morning spring weather and then try when it's hot at lunch time, but it still doesn't start. I think the problem is that the compression is just roughly around 100 psi? I already got the parts for the compression and I know I can fix that quickly but there's like something wrong with the carb or it's just that the air blows out of it before the engine dies. I don't get it. What's something I should focus on apart from the compression? I'm going to do the top end rebuild and update you guys on if anything changes.
The compression is pretty low, so your rebuild should make a big differenc. While you're at it, make sure to double-check the valve timing and clearances,if you're hearing air blowing back, it might mean a valve isn't sealing properly. Also, give that carb a good cleaning just to eliminaet any doubts. Let us know how it goes
 
I don't know what happened but my 2005 Grizzly 660 suddenly stopped working. It can't start no matter how much I try, and I even wait out the morning spring weather and then try when it's hot at lunch time, but it still doesn't start. I think the problem is that the compression is just roughly around 100 psi? I already got the parts for the compression and I know I can fix that quickly but there's like something wrong with the carb or it's just that the air blows out of it before the engine dies. I don't get it. What's something I should focus on apart from the compression? I'm going to do the top end rebuild and update you guys on if anything changes.
Has this been sorted out?
It looks like a valve timing issue like they said.
And yes, double-check for any intake leaks between the carb and the cylinder head.
A cracked boot or loose clamp could cause some funky airflow issues too.
Good luck with the rebuild!
 
I don't know what happened but my 2005 Grizzly 660 suddenly stopped working. It can't start no matter how much I try, and I even wait out the morning spring weather and then try when it's hot at lunch time, but it still doesn't start. I think the problem is that the compression is just roughly around 100 psi? I already got the parts for the compression and I know I can fix that quickly but there's like something wrong with the carb or it's just that the air blows out of it before the engine dies. I don't get it. What's something I should focus on apart from the compression? I'm going to do the top end rebuild and update you guys on if anything changes.
Yeah man, 100 psi is definitely on the low side for the 660. It's quite impossible to fire right. It also seems like your intake valve might not be sealing right. Do that top end and keep us posted.
 
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