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Discussion Starter #1
Ok my 2005 660 Grizzly 4x4 is very hard to start when cold.. It almost fouls the plug out every cold morning I try to go hunting. But once it warms up it is fine the rest of the day. Is this a firing issue or a carb issue? Thanks for any help.
 

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Have you adjusted your valves lately? I often read the first sign of valves being out of adjustment is hard starting when cold.
 
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You could start by checking out the battery if it's turning over slow. If you run thick oil and it's stupid cold it could be causing the engine to turn over slowly if the battery checks good.
 
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I agree with the above causing a hard start.
Below freezing I use starting fluid on my 660, and let it run a couple minutes before touching the throttle.
 
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Adjust your valves clearances. They have more than likely tightened up. Common on the 660 engine.
 
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Discussion Starter #7
Thanks everyone.. It has been below freezing for over a week. Has a new battery , but it was turning
over slow.. Have not checked the valves yet. It did back fire a couple times. Im charging the battery and going to try it again after I put in the shop with some heat going.
 

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Discussion Starter #8
Ok replaced plug and sprayed just quick squirt of starting fluid and this thing fired up better than it ever has.. Go figure.
 

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Ok replaced plug and sprayed just quick squirt of starting fluid and this thing fired up better than it ever has.. Go figure.
It did that because you used starting fluid. I can almost guarantee your valves are still tight and need adjustment. It's a known issue for the 660 engine. If the valves are adjusted correctly, you will not need starting fluid.

Down to about -15 C (5 degrees F), my Grizzly starts first touch of the button without starting fluid. I can actually pull start my Grizzly at that temperature.
Mine doesn't get hard to start until the -20 C (-4 F) mark. At -25 C (-13 F) it requires the use of starting fluid....but that's to be expected at those temperatures and is what starting fluid is designed for.
I have adjusted valves on many 660 engines. All owners told me the same thing. Hard to start or would not start in the cold. Once properly adjusted, they all started perfectly in the cold.
 
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Discussion Starter #10
Yes Im going to check it as soon as deer season is over. Im sure they have not been checked in a while..
 

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Yes Im going to check it as soon as deer season is over. Im sure they have not been checked in a while..
The longer you leave it the more chance there is of carbon fouling the seats & giving bad compression down the track or (worst case) burning a valve out if they tighten up too far.
 
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X2. I was putting off ajusting my valves. I would like to tell you that it is all super easy and you could do it in no time. But that isn't the case. It is a pain in the butt. You will need to remove the following: the seat, gas tank plastic, front rack, the "hood", gas tank, gas tank sheild (which also holds lots of wiring), and valve covers. That's for the intake valves. The exhaust valves only require you to remove the plug like covers. But they are not as easy to access as the intake valves. I have not gotten mine put back together yet, so I can't tell you if it seemed to make a difference or not.
 

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Discussion Starter #13
Kinda what I thought, That it might take a little time. Maybe it will be ok just about 4 more weeks left in deer season. And it only does it on the fist cold start after it warms up its fine the rest of the day.
 

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My old reliable 660 became hard to start even worse in cold weather and after having a valve adjustment done, started like it was new again.
 

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dezz and the others are right - #1 cold start prob is valves.

re-adjustment is pretty easy.

remove tank and valve covers- remove pull start cover and turn the motor forward with a wrench until your valves go loose. you should be top dead center and the timing marks should line up then.

adjust to Valve
Valve clearance (cold)
IN 0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)
----
EX 0.15 ~ 0.20 mm
(0.0059 ~ 0.0079 in)
 
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Discussion Starter #16
Ok finished adjusting valves, this thing fired right up. Even would idle with the choke on. I can hear a little bit of a lifter noise but these things where way out. I guess a little noise is ok.
 

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Ok finished adjusting valves, this thing fired right up. Even would idle with the choke on. I can hear a little bit of a lifter noise but these things where way out. I guess a little noise is ok.
Glad to hear you got your problem fixed
 

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I didn't add to your thread cause everyone was telling you what I would have suggested...adjust the valves.

Noise valves are happy valves.

Thanks for posting back the fix will help other members in the future.
 
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